Exploring the Fundamental Mysteries of the Universe by Seeing the Invisible – SciTechDaily

Michael Troxel has always liked puzzles, especially challenging ones. Which is fortunate, since his job is solving some of the most perplexing, fundamental mysteries of the universe.

At some point in middle school I asked myself, Whats the hardest thing that I could try to do? he said. And at that point the hardest thing I knew about was astrophysics, so I think that was probably the first motivation for choosing this career, if Im honest. But that was before I understood what it actually meant.

A cosmologist and assistant professor in the Department of Physics, Troxel has spent the past two years as the cosmology analysis coordinator in the Dark Energy Surveyan international collaboration involving 500 scientists analyzing a massive dataset of about 400 million celestial objects. It has been what I think is one of the most complex and difficult analyses ever performed in cosmology, which has only been possible with the contributions and leadership of dozens of my colleagues, Troxel said. The outcome will span about 30 published research papers with more than 200 contributing scientists.

Today, in recognition of his contributions to the field, Troxel was granted an award through the Department of Energy Early Career Research Program. Founded to bolster the nations scientific workforce by providing support to exceptional researchers during crucial early career years, when many scientists do their most formative work, the program will support 76 scientists in 2020. It is a welcome validation that my time supporting this project has been well spent, Troxel said. It will also give my research group the resources to tackle some of the hardest problems we face in cosmology.

The award offers five years of funding for a specific project, which Troxel will partly use to support his work on a successor to the Dark Energy Survey: research using the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), which is scheduled to begin operations in 2023, within the Dark Energy Science Collaboration (DESC). Located in Cerro Pachon, Chile, the facility is one of the three large, state-of-the-art telescopes that will come online in the coming decade, including the Nancy Grace Roman Space Telescope that Troxels group also works with. Rubin and Roman will do many of the same things that the Dark Energy Survey does, but 10 times better, Troxel said.

This DES collaboration map of dark matter was made from gravitational lensing measurements. Credit: Chihway Chang/Kavli Institute for Cosmological Physics at the University of Chicago/DES Collaboration

All focus, in part, on the two most pressing cosmological mysteries left to solve: dark matter and dark energy. Theyre the pieces of the universe that we just dont understand, Troxel said. And a bit frighteningly, they seem to make up 95 percent of the universe.

The first, dark matter, is difficult to research because scientists have yet to see itit doesnt interact with light in the way ordinary matter does. But it does interact with gravity, and current astrophysical modelswhich have been very successful at predicting how the universe has evolvedimply that there is five times as much matter as we can see in the form of this dark matter.

Troxel specializes in gravitational lensing, or how gravity bends the path of light and distorts images of distant galaxies. By taking large-scale images of the universe from observatories like Rubin and Roman and analyzing those distortions, he can map where dark matter is located. Through the Dark Energy Survey, Troxel and others have made such maps for about an eighth of the sky. Rubin will allow them to map the entire southern hemisphere.

The other mystery, dark energy, involves the expansion of the universe. Since the Big Bang, all of the universes cosmological objects have been moving away from each other. Until the last few decades, scientists largely expected that the objects would slow down due to the gravitational force pulling them back together. But the opposite is happening.

What we observed is that instead of slowing down, everything is speeding up and accelerating away from each other, Troxel said. This is like throwing a ball up in the air and instead of having it fall back down, it starts shooting up faster and faster.

Duke cosmologists pose together. Troxel is third from left. Walter is to his right and Scolnic is the last on the right. Credit: Duke University

Since the acceleration is inexplicable through gravity from massive objects, scientists have concluded that there must be another force or component of the universe at play. In fact, this other component of the universe makes up 70 percent of the dynamics of the universe, Troxel said. It is also invisible to observation, but through gravitational lensing, Troxel and his colleagues can use data from the Rubin and other telescopes to learn more about it.

With the funding from his Department of Energy Award, Troxel said he will be able to hire another graduate student and postdoc to support Dukes cosmology research, which also includes professors Dan Scolnic and Chris Walter, expanding the departments recent focus on the field. One of the benefits for students is that they will have the opportunity to visit the observatory in Chile as the commissioning of Rubin starts.

Its those opportunities to support future scientists that are most meaningful to Troxel. A first-generation student, Troxel credits those who supported his career for his current success. My path to where I am now was not easy, and I only made it due to the support of my teachers and mentors, he said.

But he also hopes to welcome a more diverse group of students into cosmology. It was only last week [with the US Supreme Court ruling on Title VII], for the first time in my life, that I am protected at the national level from being fired from my job solely for who I am, said Troxel, who is LGBTQ.

The story of modern physics and cosmology has been one of turning around our perspectives and viewing the physical world in a new light, leading to fundamental new insights about how the world works, he added. Physics and cosmology benefit from new and diverse perspectives, but we must ensure that the field is worthy of those new voices. The most rewarding part of my role now as a teacher at Duke is to help make sure the next generation of diverse voices are heard and supported while they find their own paths to grappling with the mysteries of the universe.

See more here:

Exploring the Fundamental Mysteries of the Universe by Seeing the Invisible - SciTechDaily

How Galaxies Die: New Insights Into Galaxy Halos, Black Holes, and Quenching of Star Formation – SciTechDaily

A simple model explains a wide range of observations by describing a contest between galaxy halos and their central black holes that eventually turns off star formation.

Astronomers studying galaxy evolution have long struggled to understand what causes star formation to shut down in massive galaxies. Although many theories have been proposed to explain this process, known as quenching, there is still no consensus on a satisfactory model.

Now, an international team led by Sandra Faber, professor emerita of astronomy and astrophysics at UC Santa Cruz, has proposed a new model that successfully explains a wide range of observations about galaxy structure, supermassive black holes, and the quenching of star formation. The researchers presented their findings in a paper published on July 1, 2020, in the Astrophysical Journal.

The model supports one of the leading ideas about quenching which attributes it to black hole feedback, the energy released into a galaxy and its surroundings from a central supermassive black hole as matter falls into the black hole and feeds its growth. This energetic feedback heats, ejects, or otherwise disrupts the galaxys gas supply, preventing the infall of gas from the galaxys halo to feed star formation.

The idea is that in star-forming galaxies, the central black hole is like a parasite that ultimately grows and kills the host, Faber explained. Thats been said before, but we havent had clear rules to say when a black hole is big enough to shut down star formation in its host galaxy, and now we have quantitative rules that actually work to explain our observations.

The basic idea involves the relationship between the mass of the stars in a galaxy (stellar mass), how spread out those stars are (the galaxys radius), and the mass of the central black hole. For star-forming galaxies with a given stellar mass, the density of stars in the center of the galaxy correlates with the radius of the galaxy so that galaxies with bigger radii have lower central stellar densities. Assuming that the mass of the central black hole scales with the central stellar density, star-forming galaxies with larger radii (at a given stellar mass) will have lower black-hole masses.

What that means, Faber explained, is that larger galaxies (those with larger radii for a given stellar mass) have to evolve further and build up a higher stellar mass before their central black holes can grow large enough to quench star formation. Thus, small-radius galaxies quench at lower masses than large-radius galaxies.

That is the new insight, that if galaxies with large radii have smaller black holes at a given stellar mass, and if black hole feedback is important for quenching, then large-radius galaxies have to evolve further, she said. If you put together all these assumptions, amazingly, you can reproduce a large number of observed trends in the structural properties of galaxies.

This explains, for example, why more massive quenched galaxies have higher central stellar densities, larger radii, and larger central black holes.

Based on this model, the researchers concluded that quenching begins when the total energy emitted from the black hole is approximately four times the gravitational binding energy of the gas in the galactic halo. The binding energy refers to the gravitational force that holds the gas within the halo of dark matter enveloping the galaxy. Quenching is complete when the total energy emitted from the black hole is twenty times the binding energy of the gas in the galactic halo.

Faber emphasized that the model does not yet explain in detail the physical mechanisms involved in the quenching of star formation. The key physical processes that this simple theory evokes are not yet understood, she said. The virtue of this, though, is that having simple rules for each step in the process challenges theorists to come up with physical mechanisms that explain each step.

Astronomers are accustomed to thinking in terms of diagrams that plot the relations between different properties of galaxies and show how they change over time. These diagrams reveal the dramatic differences in structure between star-forming and quenched galaxies and the sharp boundaries between them. Because star formation emits a lot of light at the blue end of the color spectrum, astronomers refer to blue star-forming galaxies, red quiescent galaxies, and the green valley as the transition between them. Which stage a galaxy is in is revealed by its star formation rate.

One of the studys conclusions is that the growth rate of black holes must change as galaxies evolve from one stage to the next. The observational evidence suggests that most of the black hole growth occurs in the green valley when galaxies are beginning to quench.

The black hole seems to be unleashed just as star formation slows down, Faber said. This was a revelation, because it explains why black hole masses in star-forming galaxies follow one scaling law, while black holes in quenched galaxies follow another scaling law. That makes sense if black hole mass grows rapidly while in the green valley.

Faber and her collaborators have been discussing these issues for many years. Since 2010, Faber has co-led a major Hubble Space Telescope galaxy survey program (CANDELS, the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey), which produced the data used in this study. In analyzing the CANDELS data, she has worked closely with a team led by Joel Primack, UCSC professor emeritus of physics, which developed the Bolshoi cosmological simulation of the evolution of the dark matter halos in which galaxies form. These halos provide the scaffolding on which the theory builds the early star-forming phase of galaxy evolution before quenching.

The central ideas in the paper emerged from analyses of CANDELS data and first struck Faber about four years ago. It suddenly leaped out at me, and I realized if we put all these things togetherif galaxies had a simple trajectory in radius versus mass, and if black hole energy needs to overcome halo binding energyit can explain all these slanted boundaries in the structural diagrams of galaxies, she said.

At the time, Faber was making frequent trips to China, where she has been involved in research collaborations and other activities. She was a visiting professor at Shanghai Normal University, where she met first author Zhu Chen. Chen came to UC Santa Cruz in 2017 as a visiting researcher and began working with Faber to develop these ideas about galaxy quenching.

She is mathematically very good, better than me, and she did all of the calculations for this paper, Faber said.

Faber also credited her longtime collaborator David Koo, UCSC professor emeritus of astronomy and astrophysics, for first focusing attention on the central densities of galaxies as a key to the growth of central black holes.

Among the puzzles explained by this new model is a striking difference between our Milky Way galaxy and its very similar neighbor Andromeda. The Milky Way and Andromeda have almost the same stellar mass, but Andromedas black hole is almost 50 times bigger than the Milky Ways, Faber said. The idea that black holes grow a lot in the green valley goes a long way toward explaining this mystery. The Milky Way is just entering the green valley and its black hole is still small, whereas Andromeda is just exiting so its black hole has grown much bigger, and it is also more quenched than the Milky Way.

Reference: Quenching as a Contest between Galaxy Halos and Their Central Black Holes by Zhu Chen, S. M. Faber, David C. Koo, Rachel S. Somerville, Joel R. Primack, Avishai Dekel, Aldo Rodrguez-Puebla, Yicheng Guo, Guillermo Barro, Dale D. Kocevski, A. van der Wel, Joanna Woo, Eric F. Bell, Jerome J. Fang, Henry C. Ferguson, Mauro Giavalisco, Marc Huertas-Company, Fangzhou Jiang, Susan Kassin, Lin Lin, F. S. Liu, Yifei Luo, Zhijian Luo, Camilla Pacifici, Viraj Pandya, Samir Salim, Chenggang Shu, Sandro Tacchella, Bryan A. Terrazas and Hassen M. Yesuf, 7 July 2020, Astrophysical Journal.DOI: 10.3847/1538-4357/ab9633

In addition to Faber, Chen, Koo, and Primack, the coauthors of the paper include researchers at some two dozen institutions in seven countries. This work was funded by grants from NASA and the National Science Foundation.

Link:

How Galaxies Die: New Insights Into Galaxy Halos, Black Holes, and Quenching of Star Formation - SciTechDaily

Spacewatch: Black holes, comets and key dates – Cosmos

The release of the closest-ever images of the Sun understandably grabbed the headlines this week (you can read Richard A Lovetts report for Cosmos here) but there was other news of note. Here are some announcements that took our fancy.

Astronomers reported watching as a supermassive black holes own corona, the ultrabright, billion-degree ring of high-energy particles that encircles a black holes event horizon, was abruptly destroyed.

The cause is unclear, though they guess it was a star caught in the black holes gravitational pull. Like a pebble tossed into a gearbox, it may have ricocheted through the disc of swirling material, causing everything in the vicinity, including the coronas high-energy particles, to suddenly plummet into the black hole.

The result was a precipitous and surprising drop in the black holes brightness, by a factor of 10,000, in under just one year.

We expect that luminosity changes this big should vary on timescales of many thousands to millions of years, says Erin Kara, from Massachussetts Institute of Technlogy, but in this object, we saw it change by 10,000 over a year, and it even changed by a factor of 100 in eight hours, which is just totally unheard of and really mind-boggling.

Following the coronas disappearance, Kara and colleagues watched as the black hole began to slowly pull together material from its outer edges to reform its swirling accretion disc. In just a few months it was able to generate a new corona, with close to its original luminosity.

Journal abstract

Another group of astronomers at the Atacama Cosmology Telescope (ACT) in Chile took a fresh look at the oldest light in the Universe and, combining these observations with a bit of cosmic geometry suggest the Universe is 13.77 billion years old, give or take 40 million years.

The new estimate matches one provided by the Standard Model of the Universe and measurements of the same light made by the Planck satellite. This adds a fresh twist to an ongoing debate in the astrophysics community, says Simone Aiola, from the Centre for Computational Astrophysics in New York.

In 2019, a research team measuring the movements of galaxies calculated that the universe is hundreds of millions of years younger than the Planck team predicted. That discrepancy suggested that a new model for the Universe might be needed and sparked concerns that one of the sets of measurements might be incorrect.

Now weve come up with an answer where Planck and ACT agree, says Aiola. It speaks to the fact that these difficult measurements are reliable.

Journal abstract

Astrophysicists from Russia, South Korea and the US are suggesting that carbon is an indication of how long a comet has been in our Solar System; the less carbon, the longer its been in the proximity of the Sun.

The proof, they say, is the comet ATLAS (C/2019 Y4), which approached the Earth in May but disintegrated, displaying a major outbreak of the carbonaceous particles.

ATLAS was expected to be the brightest comet of 2020, visible from the Earth with a naked eye. However, instead of observing the comet itself, we witnessed its disintegration, says Ekaterina Chornaya, from Russias Far Eastern Federal University.

Luckily, we had begun photometric and polarimetric studies before the process started, and because of that, we are able to compare the composition of the coma before and after the disintegration.

The researchers say the polarimetric response of the particles from Comet ATLAS matches that of one of the brightest comets in the history of Earth Comet Hale-Bopp, or C/1995 O1.

Journal abstract

To finish, a couple of important dates were revealed this week.

The Japan Aerospace Exploration Agency (JAXA) and the Australian Space Agency jointly announced that the Hayabusa2 spacecraft containing samples from the asteroid Ryugu will arrive back on Earth in Woomera, South Australia, on 6 December this year. (You can read our most recent coverage of the mission here).

And NASA announced a new target date of 31 October 2021 for the launch of the James Webb Space Telescope from French Guiana. The ongoing coronavirus COVID-19 pandemic and technical challenges have required a move from the original planned launch in March.

See the rest here:

Spacewatch: Black holes, comets and key dates - Cosmos

An open letter to Australia’s Education Minister Dan Tehan signed by 73 senior professors – The Conversation AU

This open letter is written in response to the Australian governments proposed reforms to the university sector, announced by Education Minister Dan Tehan on June 19, 2020. The so-called job-ready graduates package seeks to make courses in areas such as science, maths and teaching cheaper to encourage more students to get degrees in what the government sees to be job-growth areas. By contrast, fees for many humanities courses will more than double.

Read more: Fee cuts for nursing and teaching but big hikes for law and humanities in package expanding university places

Dear Minister,

We write regarding the recently proposed changes to Australian higher education funding. We welcome the much-needed intent to boost domestic student enrolments. But the complicated and inconsistent nature of the funding changes and the intent to identify work-relevant qualifications risk further undermining the nations fourth largest export industry at a time the Australian economy can ill afford it.

As laureate researchers spanning a wide range of disciplines in science, technology, engineering and mathematics (STEM), humanities, arts and social sciences (HASS) and other fields, we believe this proposal will bring severe negative national consequences for future university training. It is likely to have the unintentional effect of amplifying inequities in higher education, and will work against the very economic goals it is trying to achieve.

Successive Australian governments have refrained from picking winners in industry, but here we see that approach applied to education precisely at a time when future needs are becoming more heterogeneous and unpredictable.

Bracketing the humanities and social sciences as a category deemed less useful for future employment flies in the face of what we see among leaders in both politics and business. More Liberal frontbenchers, for instance, have received an arts degree than studied economics.

Business leader Jennifer Westacott, Chief Executive of the Business Council of Australia, emphasises the importance of a humanities education and Deloitte Access Economics stresses its value in teaching students to ask innovative questions, think critically for themselves, explain what they think, form ethical constructs and communicate flexibly across a range of perspectives.

Read more: If the government listened to business leaders, they would encourage humanities education, not pull funds from it

The proposed changes reflect an outdated view of both HASS and STEM. Each is concerned with advancing our understanding of the world and providing the intellectual framework and critical thinking skills needed to acquire that understanding.

These will be critical for creating a flexible, responsive workforce in an increasingly diverse economy. In the face of our uncertainty about where future needs will lie, what we can be sure of is that interdisciplinary training will become ever more important.

It is unhealthy for a democratic and inclusive society to make some fields the province of those who can pay more for them.

Different pricing is unhealthy for every academic field: the best outcomes grow from an optimal match between disciplines and the talents and interests of those who want to study them, undistorted by arbitrary price signals.

Even within its own premises, many of the subjects it claims to promote (such as maths) will suffer severe cuts. Universities may be discouraged from offering such subjects, or boost their offerings in fields that are cheaper to teach, to cross-subsidise the more expensive courses.

The recently floated patch of an integrity unit to prevent this would simply increase regulatory burdens and consume resources better spent directly on education.

Complex sets of discipline categories greatly reduce the transparency and efficiency of the system. Energy will needlessly be diverted into defining subjects into or out of categories favoured or disfavoured by the funding model.

Universities need to be able to plan intelligently, delivering world-class education and training in an uncertain 21st century. Well-intended but counter-productive distortions in the funding model will not help.

The national economic impacts of these decisions have not been convincingly worked through.

A forward-looking policy of higher-education funding thus needs to do three things:

1. Avoid complex different policies

These will necessitate increased regulation, while failing to achieve either the diversion of student numbers that are sought, or the social and technological goal of better preparing our students for the future.

The simplest way to achieve this is to reinstate a flat HECS rate a simple way to optimise the match between talent, interest and enrolment without distortions from family wealth, easy to administer, and immune from highly uncertain guesses about future trends.

2. Increase funding to universities in real terms

This will assure the growth in quality and capacity of one of Australias transformative success stories and its fourth greatest export. This should be a real increase, not funded from an arbitrary subset of future students at the outset of their careers in a time of great uncertainty.

We appreciate that the COVID-19 epidemic has put unprecedented pressures on the budget, but the need for greater support to our universities is more necessary than ever during this present time of huge financial stress, caused by the plummeting income of overseas students. Wise investment now will pay huge dividends later in the economic, scientific, social and cultural growth of the nation.

3. Integrate the systems for funding university and vocational education, which have long drifted apart

This will ensure every school-leaver has access to the level of training they need for a successful career. What is really needed is not a vocational approach to university education but a more systematic and thoughtful approach to vocational education.

In the modern economy, all kinds of work, including trades, require a broader range of skills than in the past, including communications and IT skills. We have much to learn here from the success of countries like Germany in integrating these two systems of higher education.

We urge this current piece of legislation be shelved in its current form, and replaced by one that has been drafted after proper consultation with a range of experts in the sector who are able to devise an optimal mechanism for building this vital part of our societys future.

Yours sincerely,

Professor Nicholas Evans, School of Culture, History and Language, Australian National University

Professor Chris Turney, Faculty of Science, University of New South Wales

Professor Joy Damousi, President, Australian Academy of the Humanities

Professor Christine Beveridge, School of Biological Sciences, University of Queensland

Professor John Quiggin, School of Economics, University of Queensland

Professor Matthew England, Climate Change Research Centre, The University of New South Wales

Professor Mathai Varghese, Mathematical Sciences, The University of Adelaide

Professor Sue O'Connor, Archaeology and Natural History, The Australian National

Professor Barry Brook, School of Biological Sciences, University of Tasmania

Professor Bostjan Kobe, School of Chemistry and Molecular Biosciences, University of Queensland

Professor Michael Bird, College of Science & Engineering, James Cook University

Professor Ben Andrews, Mathematical Sciences Institute, Australian National University

Professor Ian Reid, School of Computer Science, University of Adelaide

Professor Trevor J McDougall, School of Mathematics and Statistics, University of New South Wales

Professor Tamara Davis, School of Mathematics and Physics, University of Queensland

Professor Steven Sherwood, Climate Change Research Centre, University of New South Wales

Professor Peter Goodyear, Centre for Research on Learning and Innovation, The University of Sydney

Professor Madeleine JH van Oppen, Institute of Marine Science, The University of Melbourne

Professor Christopher Barner-Kowollik, School of Chemistry &Physics, Queensland University of Technology

Professor Hong Hao, Centre for Infrastructural Monitoring and Protection, Curtin University

Professor Paul S.C. Tacon, Griffith Centre for Social and Cultural Research, Griffith University

Professor Matthew Bailes, Centre for Astrophysics and Supercomputing, Swinburne University of Technology

Professor Warwick Anderson, Faculty of Arts and Social Sciences, University of Sydney

Professor Malcolm McCulloch, Oceans Institute, The University of Western Australia

Professor Lynette Russell, Monash Indigenous Studies Centre, Monash University

Professor Ping Koy Lam, Research School of Physics, The Australian National University

Professor Alexandra Y. Aikhenvald, College of Arts, Society & Education, James Cook University

Professor Chennupati Jagadish, Research School of Physics, Australian National University

Professor Margaret Jolly, School of Culture, History and Language, The Australian National University

Professor Justin Marshall, Queensland Brain Institute, University of Queensland

Professor Jason Mattingley, Queensland Brain Institute, The University of Queensland

Professor George Zhao, Faculty of Engineering,Architecture and Information Technology, The University of Queensland

Professor John Dryzek, Institute for Governance & Policy Analysis, University of Canberra

Professor Brad Sherman, School of Law, University of Queensland

Professor Richard G. Roberts, ARC Centre of Excellence for AustralianBiodiversity and Heritage, University of Wollongong

Professor Geoffrey Ian McFadden, School of BioSciences, University of Melbourne, University of Melbourne

Professor Peter Taylor, ARC Centre of Excellence for Mathematical andStatistical Frontiers, The University of Melbourne

Professor Belinda Medlyn Hawkesbury, Hawkesbury Institute for the Environment, Western Sydney University

Professor Fedor Sukochev, School of Mathematics and Statistics, University of New South Wales

Professor Michelle Coote, Research School of Chemistry, Australian National University

Professor Michael Tobar, Department of Physics, The University of Western Australia

Professor Hilary Charlesworth, Melboure Law School, The University of Melbourne

Professor Mark Finnane, School of Humanities, Languages and Social Science, Griffith University

Professor Katherine Demuth, Faculty of Medicine, Macquarie University

Professor Jolanda Jetten, School of Psychology, The University of Queensland

Professor Jon Barnett, Faculty of Science, Melbourne University

Professor Matthew Spriggs, College of Arts and Social Sciences, The Australian National University

Professor Kate Smith-Miles, School of Mathematics and Statistics, The University of Melbourne

Professor Shizhang Qiao, School of Chemical Engineering and Advanced Materials, The University of Adelaide

Professor Peter Visscher, Institute for Molecular Bioscience, The University of Queensland

Professor Zheng-Xiang, Faculty of Science and Engineering, Curtin University

Professor Toby Walsh, School of Computer Science & Engineering, UNSW Sydney

Professor Martina Stenzel, ARC Training Centre for Chemical Industries, University of New South Wales

Professor David James, School of Life and Environmental Science, University of Sydney

Professor Ross Buckley, School of Law, University of New South Wales

Professor Alex Haslam, School of Psychology, University of Queensland

Professor Stuart Wyithe, School of Physics, University of Melbourne

Professor Sara Dolnicar, Faculty of Business, The University of Queensland

Professor Lesley Head, School of Geography, University of Melbourne

Professor Glenda Sluga, Department of History, University of Sydney

Professor Ann McGrath, School of History, Australian National University

Professor Bernard Degnan, School of Biological Sciences, University of Queensland

Professor Philip Boyd, Institute for Marine and Antarctic Studies, University of Tasmania

Professor Richard Shine, Department of Biological Sciences, Macquarie University

Professor Loeske Kruuk, Research School of Biology, Australian National University

Professor Kaarin Anstey, ARC Centre of Excellence in Population Ageing Research, UNSW

Professor Paul Mulvaney, School of Chemistry, University of Melbourne

Professor Lianzhou Wang, School of Chemical Engineering, The University of Queensland

Professor Peter Waterhouse, Centre for Agriculture and the Bioeconomy, Queensland University of Technology

Professor George Willis, Mathematical and Physical Science, University of Newcastle

Read more from the original source:

An open letter to Australia's Education Minister Dan Tehan signed by 73 senior professors - The Conversation AU

Texas Tech astrophysics researcher has projects approved with Hubble Space Telescope – LubbockOnline.com

For A-J Media

For Texas Tech and the Hubble Space Telescope, three may be this year's magic number. After all, there have now been three exciting events this academic year tying the two together.

First, Paul Bennet became the first Texas Tech graduate student to be awarded Hubble observation time as a principal investigator.

Second, Texas Tech was selected to host a special commemorative event later this fall in honor of the Hubble Space Telescope's three decades in space.

And now, Tech postdoctoral research fellow Liliana Rivera Sandoval has achieved the very rare distinction of being awarded two observing times on the Hubble Space Telescope in the upcoming cycle, together with a grant to analyze existing observations. In fact, Rivera Sandoval is one of only 11 researchers worldwide to have been granted at least three proposals in the same observing cycle in the last decade.

"Since Hubble's proposal-selection process is highly competitive, it is very rare for the same person to win three awards as a PI in the same program cycle," said Sung-Won Lee, professor and chair of the Department of Physics & Astronomy. "It is a highly recognized achievement for Liliana to receive multiple observing times on the Hubble Space Telescope."

Rivera Sandoval will use her observing times on the telescope for three different research projects. In collaboration with fellow researchers at Texas Tech, across the U.S., and in Canada, Europe and Australia, Rivera Sandoval will study accreting white dwarfs and other compact binaries in globular clusters.

White dwarfs

In the life cycle of sun-like stars, or a few times in more massive ones, the white dwarf stage represents the end of their evolution. Stars, like our sun, eventually run out of nuclear fuel and shrink to smaller, fainter stars about the size of Earth. But with the mass of a sun-sized object packed into such a comparatively tiny volume, the gravity on the surface of a white dwarf is several hundred thousand times that of Earth.

Most stars typically exist in pairs called "binary systems." But what happens when both

stars in a binary system are white dwarfs? If the stars are close enough, the gravity of the more massive white dwarf can pull matter away from its companion star, leading to what astronomers call the accretion process.

A few dozen such binaries have been identified in our solar neighborhood, but never in other environments of our galaxy. That's what two of Rivera Sandoval's projects intend to investigate.

"Until now, these binaries have been predicted to exist in numerous amounts in globular clusters due to the high stellar densities there, but none have been confirmed so far," Rivera Sandoval said. "First, we want to confirm whether these ultracompact, accreting double-white dwarf binaries exist in globular clusters, as has been theorized, and in what amount so we can compare to models.

"We also want to investigate their properties and their mass-accretion process. We aim to explore whether there are differences with systems in the solar neighborhood, as that will give us direct clues on how dense stellar environments affect the creation and evolution of these binaries."

Because of their short orbits, typically less than one hour, double-white dwarf binary systems also are expected to be sources of low-frequency gravitational waves. Gravitational waves are different from electromagnetic waves and represent another tool astronomers can use to study exotic objects in the universe. So, by detecting these systems as gravitational wave sources, scientists ultimately can obtain important information about their components and their history.

"These binaries also are relevant because they are potential progenitors of supernovae type Ia, the type of supernovae that are used to measure distances," Rivera Sandoval said. "So, by using ultraviolet observations with the Hubble Space Telescope, we hope not only to confirm their existence in globular clusters for the first time, but also to discover many of these systems.

"Getting Hubble Space Telescope observations was crucial for our projects because of the unique filters and instruments it has, but also because it is the only telescope capable of resolving single stars in crowded stellar environments."

Cataclysmic variables

Rivera Sandoval's third project surveys globular clusters for a different type of binary system. Known as cataclysmic variables (CVs), these are binary systems in which a white dwarf accretes mass from a sun-like star.

"Unlike the double-white dwarf binaries, CVs have been confirmed in globular clusters, but many questions are still open," Rivera Sandoval explained.

Among those questions is why the numbers of detected CV systems and the number predicted to exist are substantially different. One potential explanation for this difference is observational biases. This means the way scientists look for these CVs can affect how many they find.

"With our project, we aim to eliminate these biases for the first time," Rivera Sandoval said. "We expect to identify the missing CV population by implementing a technique that uses different types of Hubble Space Telescope images.

"It also is unclear whether there are one or two different populations of CVs in a given cluster, and our survey will allow us to investigate that. We will study different clusters with different properties from each other. Furthermore, we don't know the orbital period distribution of CVs in globular clusters, but we intend to explore that with the Hubble Space Telescope data as well."

The project also will allow Rivera Sandoval and her team to study other types of compact binaries, such as those harboring neutron stars or even black holes.

"This is an academic dream come true," she said.

Read more from the original source:

Texas Tech astrophysics researcher has projects approved with Hubble Space Telescope - LubbockOnline.com

Fresh Twist to Debate Over Universes Age From New View of the Oldest Light in the Universe – SciTechDaily

The Atacama Cosmology Telescope measures the oldest light in the universe, known as the cosmic microwave background. Using those measurements, scientists can calculate the universes age. Credit: Image courtesy of Debra Kellner

Atacama Cosmology Telescope findings suggest the universe is 13.8 billion years old.

From a mountain high in Chiles Atacama Desert, astronomers with the National Science Foundations Atacama Cosmology Telescope have taken a fresh look at the oldest light in the universe. Their new observations, plus a bit of cosmic geometry, suggest that the universe is 13.77 billion years old, give or take 40 million years.

The new estimate matches the one provided by the standard model of the universe and measurements of the same light made by the Planck satellite, a space-based observatory that ran from 2009-2013.

This adds a fresh twist to an ongoing debate in the astrophysics community, saidSimone Aiola, first author of one of two new papers on the findings posted July 15 to arXiv.org. The trouble is that research teams measuring the movements of galaxies have calculated that the universe is hundreds of millions of years younger than the Planck team predicted. That discrepancy suggested that a new model for the universe might be needed, and sparked concerns that one of the sets of measurements might be incorrect.

Now weve come up with an answer where Planck and the Atacama Cosmology Telescope agree, said Aiola, a researcher at the Flatiron Institutes Center for Computational Astrophysics in New York City. It speaks to the fact that these difficult measurements are reliable.

A portion of a new picture of the oldest light in the universe taken by the Atacama Cosmology Telescope. This part covers a section of the sky 50 times the moons width, representing a region of space 20 billion light-years across. The light, emitted just 380,000 years after the Big Bang, varies in polarization (represented here by redder or bluer colors). Astrophysicists used the spacing between these variations to calculate a new estimate for the universes age. Credit: Image courtesy of ACT Collaboration

The age of the universe also reveals how fast the cosmos is expanding, a number called the Hubble constant. The Atacama measurements suggest a Hubble constant of 67.6 kilometers per second per megaparsec. This result agrees almost exactly with the previous estimate of 67.4 by the Planck satellite team, but its slower than the 74 inferred from the measurements of galaxies.

Making this independent measurement is really exciting because theres a mystery in the field, and this helps us sharpen our understanding of that mystery, said Jeff McMahon, an associate professor of astronomy and astrophysics at the University of Chicago who led the design of thedetectors and other new technologies used to make this measurement. This confirms the ongoing discrepancy. And we still have much more data to analyze, so this is just the beginning.

Assoc. Prof. Jeff McMahon

The close agreement between the Atacama Cosmology Telescope and Planck results and the standard cosmological model is bittersweet, Aiola said: Its good to know that our model right now is robust,but it would have been nice to see a hint of something new. Still, the disagreement with the 2019 study of the motions of galaxies maintains the possibility that unknown physics may be at play, he said.

Like the Planck satellite and its earthbound cousin the South Pole Telescope, the Atacama Telescope peers at the afterglow of the Big Bang. This light, known as the cosmic microwave background, or CMB, marks a time 380,000 years after the universes birth, when protons and electrons joined to form the first atoms. Before that time, the cosmos was opaque to light.

If scientists can estimate how far light from the CMB traveled to reach Earth, they can calculate the universes age. Thats easier said than done, though. Judging cosmic distances from Earth is hard. So instead, scientists measure the angle in the sky between two distant objects, with Earth and the two objects forming a cosmic triangle. If scientists also know the physical separation between those objects, they can use high school geometry to estimate the distance of the objects from Earth.

Subtle variations in the CMBs glow offer anchor points to form the other two vertices of the triangle. Those variations in temperature and polarization resulted from quantum fluctuations in the early universe that got amplified by the expanding universe into regions of varying density. (The denser patches would go on to form galaxy clusters.) Scientists have a strong enough understanding of the universes early years to know that these variations in the CMB should typically be spaced out every billion light-years for temperature and half that for polarization. (For scale, our Milky Way galaxy is about 200,000 light-years in diameter.)

The Atacama Cosmology Telescope measured the CMB fluctuations with unprecedented resolution and sky coverage, taking a closer look at the polarization of the light. The Planck satellite measured the same light, but by measuring its polarization in higher fidelity, the new picture from Atacama reveals more of the oldest patterns weve ever seen, said Suzanne Staggs, the telescopes principal investigator and the Henry deWolf Smyth Professor of Physics at Princeton University.

This measurement was possible thanks to new technology designed and built by McMahons team.Basically, we figured out how to make the detectors measure two colors and to pack as many into each camera as possible, McMahon said.Then we developed new lenses out of metamaterials. (Metamaterials are a type of material thats engineered to produce properties that dont exist naturally.)

From conception to deployment at the telescope to analysis, the process has spanned nearly 10 years, McMahon said. Working with this amazing team to develop this project all the way from concept sketches to producing results at the forefront of cosmology, has been absolutely fantastic.

Prof. Wendy Freedman explains a new method for measuring the expansion of the universe.

Sara Simon, now at Fermi National Accelerator Laboratory, made significant contributions to detector design; UChicago graduate student Joey Golec developed methods to fabricate the metamaterial optics; and UChicago graduate student Maya Mallaby-Kay is now working to make the datasets public.

As the Atacama Cosmology Telescope continues making observations, astronomers will have an even clearer picture of the CMB and a more exact idea of how long ago the cosmos began. The team will also scour those observations for signs of physics that doesnt fit the standard cosmological model. Such strange physics could resolve the disagreement between the predictions of the age and expansion rate of the universe arising from the measurements of the CMB and the motions of galaxies.

Were continuing to observe half the sky from Chile with our telescope, said Mark Devlin, the telescopes deputy director and the Reese W. Flower Professor of Astronomy and Astrophysics at the University of Pennsylvania. As the precision of both techniques increases, the pressure to resolve the conflict will only grow.

I didnt have a particular preference for any specific value it was going to be interesting one way or another, said Cornell Universitys Steve Choi, first author of the other paper posted to arXiv.org. We find an expansion rate that is right on the estimate by the Planck satellite team. This gives us more confidence in measurements of the universes oldest light.

###

References:

The Atacama Cosmology Telescope: DR4 Maps and Cosmological Parameters by Simone Aiola, et al., 14 July 2020, Astrophysics > Cosmology and Nongalactic Astrophysics.arXiv: 2007.07288

The Atacama Cosmology Telescope: A Measurement of the Cosmic Microwave Background Power Spectra at 98 and 150 GHz by Steve K. Choi, et al., 14 July 2020, Astrophysics > Cosmology and Nongalactic Astrophysics.arXiv: 2007.07289

The ACT team is an international collaboration, with scientists from 41 institutions in seven countries. The telescope is supported by the National Science Foundation and contributions from member institutions.

See the article here:

Fresh Twist to Debate Over Universes Age From New View of the Oldest Light in the Universe - SciTechDaily

Nvidia And University Of Florida Supercharge Education With AI Supercomputer – Forbes

Chris Malachowsky, Nvidia co-founder

Nvidia and The University of Florida (UF) are in engaging in a unique public-private partnership that could result in the development of the largest university AI supercomputer in the United States, and perhaps the world. The project is anchored by a $25 million gift from UF alumnus and Nvidia co-founder, Chris Malachowsky along with a matching $25 million grant from Nvidia in the form of hardware, software, training, and services, as well as an additional $20 million from UF for data center upgrades.

The project was inspired by Malachowsky who was looking for a way to help the university expand its reach and bring artificial intelligence (AI) to the forefront at UF. The initiative includes a commitment from UF to hire 100 additional faculty members focused on AI. They will join 500 new faculty recently added across disciplines many of whom will weave AI into their teaching and research. The University expects to integrate the use of this AI supercomputer throughout various departments. In addition, the University is introducing a Bachelor of Science degree in Data Science this fall.

Malachowsky hopes this unique project will become a template for other universities and companies to follow. He is quoted as saying: Artificial intelligence is the most disruptive technology of our era, with sweeping implications for how we live and work. In my conversation with Malachowsky he expressed great enthusiasm for bringing AI to a broad set of disciplines at the UF - from precision agriculture, to astrophysics, and to marine biology. The obvious applications are in engineering disciplines for applications such as autonomous driving research. In addition, Malachowsky also expects there will be courses in other areas such as the ethics of AI and journalism to understanding the impact of AI on society.

Malachowsky believes that the Nvidia AI supercomputer will enhance research into all these areas with both number crunching and machine learning capability. In particular, he believes that solving some of the toughest problems we face today, such as alternative energy and climate change, requires an interdisciplinary approach that includes massive compute power and machine learning for simulation and modeling.

Overall, there would be an general enhancement to STEM (short for Science, Technology, Engineering, Math) education throughout the University. The system that Nvidia will be delivering to UF later this year which will be up and running just a few weeks later is an Nvidia DGX SuperPOD. A similar, though larger, in-house system at Nvidia called Selene is in the No. 7 spot in the latest Top500 supercomputer list with an HPL mark of 27.58 petaflops. The DGX SuperPOD is powered by Nvidas new Ampere A100 GPUs and AMDs EPYC Rome CPUs and uses Mellanox HDR InfiniBand as the system network. Separately, it was announced earlier this year that UF was the first institution of higher learning in the U.S. to receive DGX A100 systems, which have already been deployed in an existing supercomputer.

NVIDIA SuperPOD Data Center

This public-private initiative could be a model for other industry and academic collaborations. Alumni can work with their alma mater, industry, and local governments to make significant hardware and monetary contributions while the universities would provide the academic environment and the researchers to put that hardware to work. Malachowsky believes that this type of program can help to improve the United States international competitiveness if it were to be replicated. UF is already moving ahead with improving access to its technology and will make the AI supercomputer available to other state and regional schools.

Malachowsky believes this really is a moonshot opportunity for the University and for all educators to leverage this unprecedented access to advanced compute capability and AI to advance the country.

The author and members of the Tirias Research staff do not hold equity positions in any of the companies mentioned. Tirias Research tracks and consults for companies throughout the electronics ecosystem from semiconductors to systems and sensors to the cloud. Members of the Tirias Research team are tracking all the developments in AI technology and have consulted for Nvidia and other companies focused on AI solutions. The author was an Nvidia employee from 2006 to 2010.

Link:

Nvidia And University Of Florida Supercharge Education With AI Supercomputer - Forbes

Here’s why today’s Google Doodle is celebrating the Turkish astrophysicist Dilhan Eryurt – Yorkshire Post

Read This

Monday, 20th July 2020, 11:04 am

Today's Google Doodle celebrates Dilhan Eryurt, a Turkish astrophysicist who played a huge role in the way we understand how the Sun was formed.

But who was she, what were some of her notable achievements, and why has Google chosen today to honour her?

Here's everything you need to know.

Who was Dilhan Eryurt?

Born in 1926 in zmir - Turkey's third most populous city - Prof. Dr. Dilhan Eryurt grew up across the country, first moving to Istanbul with her family, and then on to Turkey's second city, Ankara, a few years later.

After developing an interest in mathematics in high school, Eryurt enrolled in the Istanbul University Department of Mathematics and Astronomy, and upon graduation, was assigned to open an Astronomy Department at Ankara University.

She relocated to the US to continue her graduate studies at the University of Michigan, and while there completed her doctorate at the Ankara University Department of Astrophysics, becoming Associate Professor.

From 1961, Eryurt held a position at NASA's Goddard Space Flight Centre, her appointment extra notable for the fact she was the only female astronomer working at the institution at the time.

What did she study?

Eryurt's work at Goddard revealed some facts about the Sun that were not yet understood.

For instance, she observed that the brightness of the Sun had not increased - it had in fact decreased - since its formation 4.5 billion years ago, revealing that our nearest star was much brighter and warmer in the past.

Her studies influenced the course of the scientific and engineering research aims of space flights - a new and uncharted territory at the time.

In 1969 she was awarded the Apollo Achievement Award for contributions to the Apollo 11 mission. Today (20 July) marks 51 years since Buzz Aldrin, Neil Armstrong and Michael Collins landed and walked on the moon.

Aldrin and Armstrong spent a total of 21 hours and 36 minutes on the moon, but the Apollo 11 mission itself lasted a total of eight days, three hours, 18 min, and 35 seconds.

This is likely the reason Google have chosen today to celebrate Eryurt's life; her research provided NASA engineers with crucial information for modelling solar impact on the lunar environment

She later moved on to work at the California University, where she studied the formation and development of Main Sequence stars - a continuous band of stars that appear on plots of stellar colour versus brightness.

What else did she do?

Throughout her long and successful career, Eryurt became an award-winning astronomer, picking up all sorts of nods for her contributions and work.

Other notable achievements of hers include the organising of Turkey's first National Astronomy Congress in 1968, and the establishment of the Astrophysics Department at the Middle East Technical University.

She retired in 1993 after a long career, and sadly died in September 2012 at the age of 85, suffering a heart attack in Ankara.

See more here:

Here's why today's Google Doodle is celebrating the Turkish astrophysicist Dilhan Eryurt - Yorkshire Post

UChicago scientists reflect on need to address racism, inequality – UChicago News

When physicist Brian Nord joined the Dark Energy Survey in 2012, a state-of-the-art project to map the night sky, he wasas far as he knewthe only Black American man in the multi-institution collaboration of more than 400 scientists. Today, he still is.

When I was a child, I wanted to grow up to share the beauty and gifts of a scientific understanding of the universe with the world, Nord wrote in an open letter to global colleagues. Ive had the privilege to find and create knowledge for my fellow humans. Im one of the lucky ones. How many have shared my dream, but never got this close, because of the science communitys complicity through inaction?

An associate scientist at Fermilab and University of Chicago visiting research assistant professor, Nord is a member of Particles for Justicean international movement of scientists that works to counter social injustice in science. He and astrophysicist Chanda Prescod-Weinstein of the University of New Hampshire co-led a call for a day of action June 10 in which non-Black scientists would plan how to better support their Black colleagues and address the racial injustices in society, academia and in science.

Thousands of scientists around the world participated. Large scientific collaborations like LIGO, the Rubin Observatory Legacy Survey of Space and Time and the Dark Energy Survey cancelled their meetings; the journals Science and Nature,as well as the popular site arxiv.org, paused their publishing. Instead, scientistsincluding many in the physical sciences at UChicagoread, reflected, donated and met on how to move forward.

Our Black colleagues do not feel safe in our work environment. Thats not OK, said astrophysicist and graduate student Adina Feinstein, who is white. For academia as an institutiona space that prides itself on boundless creativity and innovationto be systemically racist is so backwards. But we are using the momentum of the current atmosphere to strongly push for these changes.

Feinstein and Thaddeus Komacek, a postdoctoral researcher in the Geophysical Sciences, lead a discussion in the Exoplanet Journal Club and came up with a list of immediate initiatives for the group. They, along with other scientists in the Inclusivity, Diversity, and Equity in Astronomy group, also pulled together a list of larger, concrete action items that the astronomy community could undertake to improve equity.

Chihway Chang, the Clare Booth Luce Assistant Professor of Astrophysics, also discussed action plans within the Survey Science group she led together with Asst. Prof. Alex Drlica-Wagner. Chang, who grew up in Taiwan, said the past few weeks of protest and discussion in the U.S. have been transformational for her.

In the beginning, I think I didnt really understand the full extent of the problem since I didnt grow up here and have less of the cultural background, she said. But inequality in academiathat is something I understand. As a woman in science, I think back on all the incidents in my academic career where I thought, Should I say something? and I stayed quiet because it felt like it wasnt going to change anything.

This feels different, she said. This feels like change is possible. And now that Im faculty, I especially have the responsibility to make changes, she said. You need to do that to show students its OK to speak up.

Nord agreed.

Sometimes people hear and respond empathetically, but its usually behind closed doors, he said. My colleagues are still realizing the need to publicly hold each other accountable when racist, misogynistic or homophobic things are said. You can still uphold the values of free speech and also hold people accountable for racist statements.

Sam McDermott, a Kavli Institute for Cosmological Physics associate fellow, also helped organize the day of action. He spoke on the need for white scientists like himself to educate each other and hold each other accountable.

No one likes to hear that theyre part of a racist establishment, he said. Its often met with defensiveness or evasiveness. Ive had some good, sincere conversations with people in power in the past few weeks; but itll be a really long time before we know how much they really meant it.

Theres really one metric for success, McDermott added: Do our institutions reflect the makeup of the country as a whole at every leveldirectorships, department chairs, collaboration heads, postdocs and students?

As for a plan, Nord said: Go find where Black people do physics. Hire them and retain them. Pay them competitively and for skills they have, like how to manage white supremacyBlack people have been doing a lot of work for the academy that we dont get paid or recognized for. Thats how you rebuild your institution in a way that is just and equitable.

Original post:

UChicago scientists reflect on need to address racism, inequality - UChicago News

Comet NEOWISE: How to See It in Night Skies – The New York Times

Eager sky watchers are turning to the heavens as Comet NEOWISE, one of the brightest comets in a generation, starts climbing ever higher among the evening stars.

A majority of comets fly through the solar system invisible to humans, usually too small and dim to be seen with the naked eye. The last frozen ice ball that gave us a big show was Hale-Bopp, a comet that was visible for nearly 18 months around its closest approach to Earth in 1997.

Officially designated C/2020 F3, Comet NEOWISE was discovered on March 27 and had until this week been visible only to committed comet viewers willing to wake up in the early pre-dawn hours. But on Monday, NEOWISE tipped into the post-sunset sky and has even been spotted by people living near city centers with all the light pollution.

Its the first time in 23 years that this is possible, said Federica Spoto, an astronomer at the Harvard & Smithsonian Center for Astrophysics. You can watch it from your backyard and you dont need a telescope.

To catch NEOWISE yourself, look up at the northwest skies about an hour and a half after sunset. Experts suggest going to the darkest area you can for best viewing. Find the Big Dipper and follow its ladle as it arcs in the direction of the horizon.

NEOWISE will appear under the Big Dipper about 10 degrees above the horizon and be about as bright as that constellations stars. If you hold out your arm, 10 degrees is roughly the part of the sky covered by your fist. Over the next few days, NEOWISE will move higher in the sky and be easier to spot, reaching its apex on July 23, when it makes its closest approach to Earth.

Good binoculars will allow you to see more of the comet and its spectacular dust tail. Lucky viewers might even catch the fainter blue ion tail, made from charged particles flying off the comets icy nucleus. NEOWISE is visible only to observers in the Northern Hemisphere and should remain bright enough to spot into mid-August.

For those looking to capture a souvenir of their experience, a digital camera placed on a tripod and set to a five- or 10-second exposure could do the trick, said Ernesto Guido, an amateur astronomer in Italy. Many cellphones allow users to change the settings on their cameras and achieve surprisingly good results. Try framing NEOWISE against a nice background such as a tree, Mr. Guido suggested.

Comet NEOWISE gets its name from NASAs Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE), a space-based infrared telescope dedicated to looking out for potentially hazardous asteroids and comets. Researchers who manage the observatory spotted the comet in March when it was headed in the direction of the sun.

Comet NEOWISE made its closest approach to our star on July 3, coming within the orbit of Mercury.

A smaller or weaker comet would have crumbled under the pressure, said Amy Mainzer, principal investigator of the NEOWISE mission.

Thats exactly what happened earlier this year to Comet SWAN, which was just barely visible to naked-eye viewers in the Southern Hemisphere, before fizzling as it rounded the sun. Another comet, ATLAS, disintegrated into more than two dozen pieces in April.

NEOWISE comes to us from the distant outer reaches of the solar system, having spent most of its life in a frigid field of icy bodies called the Oort cloud. When far from the sun, comets are inert and lack their beautiful dust tails, which can be 10 million miles long. The suns heat causes them to expel gas and dust, forming an atmospheric shell called a coma and then the pressure of solar radiation extends this structure out into a long tail.

Comets like NEOWISE are leftovers from our solar systems creation. Since they retain the building blocks of planets in their frozen ice, they can provide scientists with important information about our origins. Dr. Mainzer likened its approach to a mission that collects samples and returns them to Earth, except the sample comes to us.

NEOWISE wont make it back to the inner solar system for 6,800 years. So enjoy it while you can.

Things are really tough right now for lots of people, Dr. Mainzer said. But this is a chance to look up and reconnect with the big picture stuff.

See the rest here:

Comet NEOWISE: How to See It in Night Skies - The New York Times

Comet Neowise: How To See It On Long Island – Patchogue, NY Patch

LONG ISLAND Comet Neowise is zooming past the planet, and you'll be able to see it in the skies above Long Island for the next several days. To see the brightest comet in nearly a quarter of a century, all you need is a little patience.

Comet Neowise has been visible in the east-northeast sky with the naked eye about an hour before sunrise for the past month. The comet, which NASA says could become known as the "Great Comet of 2020," is going prime time, though, and this week it is visible in the evening sky.

It will appear in the northwestern sky about an hour after sunset, below the Big Dipper, according to NASA.

Though you'll be able to see it without a small telescope or binoculars, weather permitting, those instruments offer better views.

Sky & Telescope says Comet Neowise will appear just as the last of twilight fades into darkness. The Big Dipper hangs by its handle at this time, so look about three fists below the "bowl."

Comet Neowise will fade after July 19 as it comes closer to our planet. Its closest approach to Earth occurs on July 22, after which it will fade more rapidly and eventually disappear from our solar system.

The comet has brightened 100-fold since June 9 and is only getting better especially for those with an aversion to early mornings.

The comet appears to rise tail first, followed by its bright head or coma, which Space.com said shines "as bright as a first-magnitude star" a designation reserved for some the brightest of stars. For comparison purposes, Polaris, the North Star, is a second-magnitude star. Since magnitude is a logarithmic scale, the comet will appear to be about 2.5 times brighter than Polaris.

Comet Neowise appears low on the horizon, so early morning viewers will need to plan to get away from trees and buildings. It's also competing with a nearly full moon, which can make it hard to see.

Relatively new in the continuum of time, Comet Neowise hasn't made an appearance in our solar system for 6,800 years.

NASA says the comet is an inner-solar system "intruder" that could become known as the Great Comet of 2020. It's large by comet standards, measuring about 3 miles across.

The comet is the brightest to visit Earth since Comet Hale-Bopp made an appearance in 1997.

Follow this link:

Comet Neowise: How To See It On Long Island - Patchogue, NY Patch

Ghostly Particles from the Sun Confirm Nuclear Fusion – Eos

Deep within the Sun, high temperatures and pressures drive the fusion of hydrogen into helium. Absent these nuclear reactions, Earth would be a cold and dark world devoid of life. Now, using an exquisitely sensitive detector located deep underground, researchers have made the first direct observation of a rare breed of ghostly particles known as solar neutrinos. This discovery confirms a long-hypothesized mechanism for how the Sunand other starsfuses hydrogen into helium.

Over 8 decades ago, physicists Hans Bethe and Carl Friedrich von Weizscker independently proposed that hydrogen fusion in the Sun might be catalyzed by carbon (C), nitrogen (N), and oxygen (O) nuclei. Researchers now understand that this so-called CNO cycle accounts for only a small fraction of the energy produced by the Sunroughly 1%but its a dominant mechanism in more massive stars. (Most of the Suns energy derives from a fusion process known as the pp chain.)

Both the pp chain and the CNO cycle produce neutrinos. These electrically neutral, nearly massless particles pervade space, yet theyre maddeningly tough to pin down because they interact so weakly with matter. Neutrinos are very difficult to detect, said Sarbani Basu, a solar and stellar astrophysicist at Yale University in New Haven, Conn., not involved in the research. They pass right through you. (Hold up a hand. Tens of billions of neutrinos just zipped through.)

Neutrinos are a hallmark of the Suns nuclear reactions, and theyre a fundamental way of studying processes that occur deep within our nearest star. But it wasnt until 2014 that researchers reported detecting neutrinos from the primary reaction of the pp chain. Now that same research group has pinpointed neutrinos from the CNO cycle.

The team used the Borexino particle detector located roughly 1,400 meters underground near Rome, Italy. (The detectors subterranean environment shields it mightilybut not completelyfrom a barrage of cosmic particles.) The heart of Borexino is a spherical tank roughly 4 meters in diameter filled with about 280 metric tons of a liquid hydrocarbon. This scintillator liquid emits light whenever a charged particle moves through it. If a neutrino happens to collide with an electron in the tank, the resulting burst of light is captured by photomultiplier tubes within the detector. Neutrinos from the CNO cycle can be distinguished on the basis of the kick they impart to electrons.

One long-standing challenge to detecting CNO cycle neutrinos has been background contamination. For example, the radioactive decay of bismuth-210, found in the nylon lining Borexinos innermost tank, releases charged particles that can trigger bursts of light, said Gioacchino Ranucci, an astroparticle physicist at the National Institute for Nuclear Physics in Milan, Italy, and a spokesman for the Borexino Collaboration. Even if its a small amount, it can mask the signal of the neutrinos.

To combat this contamination, the scientists carefully controlled Borexinos thermal environment. They clad the detector in a thick layer of insulation and installed a heater nearby. Those efforts minimized convective currents within the detectors liquid, important for preventing the dispersal of bismuth-210 and its daughter products. The research team also limited its analyses to signals originating from deep within Borexinos innermost tank, far from the detectors nylon lining.

This discovery is another milestone in solar neutrino physics.Last month, at the XXIX International Conference on Neutrino Physics and Astrophysics, the Borexino Collaboration reported a confident detection of CNO cycle neutrinos based on 3.5 years of data. Borexino spotted about seven of these elusive particles each day, the team estimated.

This discovery is another milestone in solar neutrino physics, the team of nearly 100 reported in an accompanying paper.

These results are exciting, said Yales Basu, but the error bars on the detection are still large. Those will get smaller as more data are collected, so its important to keep the experiment going, she said. Keep observing, keep observing.

Katherine Kornei (@KatherineKornei), Science Writer

Original post:

Ghostly Particles from the Sun Confirm Nuclear Fusion - Eos

Trending Today Corona impact on X-Ray Screening System Market 2020-2025, Studied in Detail along with Top Companies as- ADANI, Smiths Detection,…

The global X-Ray Screening System Market is carefully researched in the report while largely concentrating on top players and their business tactics, geographical expansion, market segments, competitive landscape, manufacturing, and pricing and cost structures. Each section of the research study is specially prepared to explore key aspects of the global X-Ray Screening System Market. For instance, the market dynamics section digs deep into the drivers, restraints, trends, and opportunities of the global X-Ray Screening System Market. With qualitative and quantitative analysis, we help you with thorough and comprehensive research on the global X-Ray Screening System Market. We have also focused on SWOT, PESTLE, and Porters Five Forces analyses of the global X-Ray Screening System Market.

Leading players of the global X-Ray Screening System Market are analyzed taking into account their market share, recent developments, new product launches, partnerships, mergers or acquisitions, and markets served. We also provide an exhaustive analysis of their product portfolios to explore the products and applications they concentrate on when operating in the global X-Ray Screening System Market. Furthermore, the report offers two separate market forecasts one for the production side and another for the consumption side of the global X-Ray Screening System Market. It also provides useful recommendations for new as well as established players of the global X-Ray Screening System Market.

Final X-Ray Screening System Report will add the analysis of the impact of COVID-19 on this Market.

X-Ray Screening System Market competition by top manufacturers/Key player Profiled:ADANI, Smiths Detection, Scanna, Astrophysics Inc., UTI Grup, Bavak Beveiligingsgroep, L3 Security & Detection Systems, Rapiscan Systems, Nuctech

>>> Get Free Sample PDF (including COVID19 Impact Analysis, full TOC, Tables and Figures) of X-Ray Screening System Market:

The global X-Ray Screening System market was valued at $XX million in 2019, and MAResearch analysts predict the global market size will reach $XX million by the end of 2029, growing at a CAGR of XX% between 2019 and 2029.

Since the COVID-19 virus outbreak in December 2019, the disease has spread to over 210 countries and territories around the world and 2 international conveyances. The global impacts of COVID-19 are already starting to be felt, and will significantly affect this industry in 2020.

This report analyses the impact of COVID-19 on this industry. COVID-19 can affect the global market in 3 ways: by directly affecting production and demand, by creating supply chain and market disruption, and by its financial impact on enterprises and financial markets.

This report provides detailed historical analysis of global market for X-Ray Screening System from 2014-2019, and provides extensive market forecasts from 2020-2029 by region/country and subsectors. It covers the sales volume, price, revenue, gross margin, historical growth and future perspectives in the X-Ray Screening System market.

Segmentation by Product:

People X-ray ScreeningBaggage & Cargo X-ray ScreeningVehicle X-ray ScreeningOthers

Segmentation by Application:

Prisons and Correctional FacilitiesCustoms and Border CrossingsMines and Industrial SecurityHotels, Public and Government BuildingsOthers

Competitive Analysis:

Global X-Ray Screening System Market is highly fragmented and the major players have used various strategies such as new product launches, expansions, agreements, joint ventures, partnerships, acquisitions, and others to increase their footprints in this market. The report includes market shares of X-Ray Screening System Market for Global, Europe, North America, Asia-Pacific, South America and Middle East & Africa.

Scope of the Report:The all-encompassing research weighs up on various aspects including but not limited to important industry definition, product applications, and product types. The pro-active approach towards analysis of investment feasibility, significant return on investment, supply chain management, import and export status, consumption volume and end-use offers more value to the overall statistics on the X-Ray Screening System Market. All factors that help business owners identify the next leg for growth are presented through self-explanatory resources such as charts, tables, and graphic images.

The report offers in-depth assessment of the growth and other aspects of the X-Ray Screening System market in important countries (regions), including:

North America(United States, Canada and Mexico)

Europe (Germany, France, UK, Russia and Italy)

Asia-Pacific (China, Japan, Korea, India, Southeast Asia and Australia)

South America (Brazil, Argentina, Colombia)

Middle East and Africa (Saudi Arabia, UAE, Egypt, Nigeria and South Africa)

Our industry professionals are working reluctantly to understand, assemble and timely deliver assessment on impact of COVID-19 disaster on many corporations and their clients to help them in taking excellent business decisions. We acknowledge everyone who is doing their part in this financial and healthcare crisis.

For Customised Template PDF Report:https://www.reporthive.com/request_customization/2377373

Table of Contents

Report Overview:It includes major players of the global X-Ray Screening System Market covered in the research study, research scope, and Market segments by type, market segments by application, years considered for the research study, and objectives of the report.

Global Growth Trends:This section focuses on industry trends where market drivers and top market trends are shed light upon. It also provides growth rates of key producers operating in the global X-Ray Screening System Market. Furthermore, it offers production and capacity analysis where marketing pricing trends, capacity, production, and production value of the global X-Ray Screening System Market are discussed.

Market Share by Manufacturers:Here, the report provides details about revenue by manufacturers, production and capacity by manufacturers, price by manufacturers, expansion plans, mergers and acquisitions, and products, market entry dates, distribution, and market areas of key manufacturers.

Market Size by Type:This section concentrates on product type segments where production value market share, price, and production market share by product type are discussed.

Market Size by Application:Besides an overview of the global X-Ray Screening System Market by application, it gives a study on the consumption in the global X-Ray Screening System Market by application.

Production by Region:Here, the production value growth rate, production growth rate, import and export, and key players of each regional market are provided.

Consumption by Region:This section provides information on the consumption in each regional market studied in the report. The consumption is discussed on the basis of country, application, and product type.

Company Profiles:Almost all leading players of the global X-Ray Screening System Market are profiled in this section. The analysts have provided information about their recent developments in the global X-Ray Screening System Market, products, revenue, production, business, and company.

Market Forecast by Production:The production and production value forecasts included in this section are for the global X-Ray Screening System Market as well as for key regional markets.

Market Forecast by Consumption:The consumption and consumption value forecasts included in this section are for the global X-Ray Screening System Market as well as for key regional markets.

Value Chain and Sales Analysis:It deeply analyzes customers, distributors, sales channels, and value chain of the global X-Ray Screening System Market.

Key Findings: This section gives a quick look at important findings of the research study.

About Us:Report Hive Research delivers strategic market research reports, statistical surveys, industry analysis and forecast data on products and services, markets and companies. Our clientele ranges mix of global business leaders, government organizations, SMEs, individuals and Start-ups, top management consulting firms, universities, etc. Our library of 700,000 + reports targets high growth emerging markets in the USA, Europe Middle East, Africa, Asia Pacific covering industries like IT, Telecom, Semiconductor, Chemical, Healthcare, Pharmaceutical, Energy and Power, Manufacturing, Automotive and Transportation, Food and Beverages, etc. This large collection of insightful reports assists clients to stay ahead of time and competition. We help in business decision-making on aspects such as market entry strategies, market sizing, market share analysis, sales and revenue, technology trends, competitive analysis, product portfolio, and application analysis, etc.

Contact Us:

Report Hive Research

500, North Michigan Avenue,

Suite 6014,

Chicago, IL 60611,

United States

Website: https://www.reporthive.com

Email: [emailprotected]

Phone: +1 312-604-7084

See the original post:

Trending Today Corona impact on X-Ray Screening System Market 2020-2025, Studied in Detail along with Top Companies as- ADANI, Smiths Detection,...

Spectacular sight: 5 planets together appeared in Karachi at midnight – The News International

KARACHI: Five planets of the solar system witnessed together at 12 on Sunday night in the Pakistan sky, a top planetary scientist announced.

The five planets that were viewed simultaneously including Mercury, Venus, Mars, Jupiter, and Saturn, according to Prof Dr Muhammad Jawed Iqbal, the director at the Institute of Space and Planetary Astrophysics (ISPA) a research facility at the University of Karachi.

"Five planets were visible together at midnight and all five could be seen without binoculars," Dr Iqbal said. "Usually, two to three planets are visible in the night sky.

The scientist noted that the coming together of the planets would be available for viewing for the next few nights. However, it would be difficult to see the interesting activity in the sky due to Karachis current cloudy weather.

It is interesting to note that at the same time, Mercury was in retrograde (apparent motion of moving backwards) for the second time this year, from June 18 to July 12, 2020, according to Forbes. Furthermore, the ringed Saturn would be brightest at night on July 20, the publication added, as it would reach opposition.

See the original post:

Spectacular sight: 5 planets together appeared in Karachi at midnight - The News International

COVID-19 in Fall 2020: A Concerning Situation for Students – Astrobites

The following is based on a collection of graduate student experiences, focusing on the perspectives of students at U.S. institutions. Information on university reopening plans and COVID-19 is up-to-date as of early July 2020, but may have changed due to the quickly evolving nature of this pandemic. For medical information on COVID-19, please refer to the CDC and WHO.

A few months ago, the novel coronavirus SARS-CoV-2 leapt to the forefront of our national consciousness. COVID-19, the highly infectious disease caused by this new coronavirus, began to spread in communities in the United States and across the globe. In response, entire countries shut down, advising citizens to stay in their homes to slow transmission and flatten the curve to avoid overwhelming healthcare systems. Universities scrambled to make changes, with many institutions transitioning to online learning in a matter of days or weeks. Many students were told to leave campuses, finishing out the school year in their family homes.

Now, as we approach the fall term, universities are planning for what comes next. Some states have reopened their businesses and relaxed stay-at-home orders, leading to increased cases of COVID-19 across the country. Universities are considering how they, too, will reopen, and if/how they will safely bring students back on campus for Fall 2020. As graduate students we are deeply concerned with how universities will operate and how we (as students, researchers, and teaching assistants) will be impacted by COVID-19 this fall. In todays Beyond bite, we will explore the variety of current university reopening plans and graduate student concerns surrounding those plans.

Before we jump into how universities are tackling this issue of reopening, its important to understand the current situation in the U.S. Although some countries like New Zealand have effectively halted the spread of COVID-19, the United States has seen cases rise dramatically (see Figure 1), currently holding the highest case counts in the world with over 3 million confirmed cases according to the WHO. (For context, as of 6/30/2020, the U.S. had 4% of the worlds population and 25% of its COVID-19 cases.) The fatality rate of COVID-19 is around 0.6-1% overall according to current studies, and the hospitalization rate is ~10-11%. The data have shown that people 65 and older, as well as people of color (particularly Native American, Black, and Latinx communities), are at higher risk for COVID-19.

Even in cases where the patient survives and recovers, they have been left with life-changing effects, such as decreased lung capacity, strokes, and more. To make matters worse, cases that dont show serious symptoms can still be left with long-term lung damage. Over 100,000 Americans have already died from this pandemic, and infection rates are spiking in many states. There is a lack of contact tracing, widespread testing, and other efforts that countries have used to control the spread. Current scientific consensus shows that the virus is transmitted by respiratory droplets, even by asymptomatic folks, and also possibly through the air. As a result, gatherings indoors are more risky due to a lack of space for distancing and less air flow. While mask wearing and washing your hands is useful (but not foolproof) in reducing the spread, isolation is the most surefire way to avoid infection. Maintaining distancing, implementing contact tracing and testing, and enforcing these safety protocols seems challenging in a university setting, where students often gather in groups to study and socialize. With these facts in mind, how are universities going to serve tens of thousands of students in the fall and keep everyone safe?

The United States has so far lacked cohesive national guidance during this pandemic, leaving decisions for reopening plans and public health guidance to the state (and even city) levels of government. For many people, there has been a large amount of uncertainty about what activities are allowed by their local rules, and, beyond that, what is actually safe. So far, it seems like universities are adding to this patchwork quilt of reopening plans, with a huge variance in what individual institutions are planning to do this fall (see Figure 2 for a summary). Most plans seem to offer some sort of hybrid in-person and virtual instruction, although the details of these plans vary wildly. Additionally, these plans were recently thrown into disarray by the ICE decision regarding international students, which has thankfully now been rescinded.

Many universities have been committed to offering in-person instruction as much as possible. For example, Boston University stated in a memo to deans and department chairs that any course that does not have a significant in-person component incrementally erodes the residential character of the BU experience. Their plan, titled Learn from Anywhere (LfA), sets in-person instruction as the default for course delivery, with options for virtual teaching for students who cannot or do not wish to attend in-person. The University of Michigan stated that it will have an in-person public health informed semester without giving significant detail on what that means, only generally stating that large classes will be held remotely, small classes will be held in-person, and medium-size classes will be a hybrid of the two. The Chancellor of NC State University, in a memo sent to deans, directors, and department heads, requested an increase in the number face-to-face and hybrid courses being offered. The University is planning to have lecture classes of up to 100 students with a proposed classroom spacing of 46 feet. (Dr. Katie Mack, a physics professor there, wrote a response letter to this memo, detailing why this plan is a mistake.)

Another strategy has been shifting schedules to accommodate fractions of the campus population at different times. For example, Columbia University plans to have a three term schedule with freshman and sophomores on campus in fall, and juniors and seniors on campus in Spring. University of Massachusetts Amherst has shifted to start classes 2 weeks early, and a few schools are holding in-person classes until Thanksgiving, after which theyll go entirely online. Some plans are intentionally vague and leave decisions up to departments, or even individual instructors, and some are a bit unconventional. A rare few schools have plans that seem possibly safe, such as UCLA, where they expect most classes to be online except those that petition for a need to be in-person, and have sent rigorous emails detailing plans for safety protocols (including contact tracing and widespread testing) on campus. The University of Vermont has adopted a model that gives students the choice to stay home and take virtual classes, allowing them to determine their own risk and comfort level about being physically on campus (however, only 40% of classes will be available online). Harvard has fully committed to 100% online courses.

Although there are many variations of university reopening plans, there are a few themes that appear frequently, listed below.

The general consensus surrounding these plans seems to be that students are terrified and concerned that the results will be disastrous. Students are frustrated with the confusing, conflicting information theyve been given about university reopening, and the sometimes convoluted new schedules and rules theyve been given about what to expect next school year.

For undergraduates, the scarcity of housing at some institutions (due to lower capacity to ensure social distancing) poses an issue for students. For those that would be living in the dorms, there are significant concerns about safety and maintaining distancing in such a tightly packed space. Many students have expressed that paying full tuition and campus fees when many campus services arent being offered seems unfair, even starting petitions for tuition reimbursement or reduction.

The major problem with current plans is that many of them simply arent realistic. Do we really expect all students to comply? In this pandemic, even one rogue infected person (particularly a super-spreader) can spread COVID-19 to classmates, dormmates, and friends without even knowing it. As a result, compliance is required for everyone in the community for anyone to stay safe. This is a problem when students have already been gathering more, spurred by the idea that as young people theyre lower risk, some going as far as having COVID parties which act as contests and sometimes offer money to the first person who gets the disease. Additionally, colleges are filled with high-risk areas for COVID-19, such as the crowded and high contact areas of dorms, dining halls, community bathrooms/facilities, and classrooms. In order to make these spaces safe, the measures that will have to be implemented significantly degrade the residential experience that colleges are desperately trying to cling to. If the importance of in-person classes is to have the quintessential college experience, these plans are missing the point; with rigorous distancing in classrooms, significantly reduced social activities and student group meetings, and strict quarantines in dorms, the college experience of close collaboration and intense social bonding just isnt happening.

Given that most schools are attempting some hybrid format, this leads to the question: how do you coordinate students in-person and online simultaneously? Also, with infection rates rising in 46 states, it is definitely possible that schools will have to abruptly close again, leaving us in the same unprepared and haphazard state we found in March. Students may once again have to hurriedly leave campus, or at least return to fully online classes with no in-person contact. What happens then if classes have to switch to fully virtual again? Both these scenarios require significant extra labor on the part of the instructor and TAs and could cause disruption to the student learning experience. Abruptly switching to online or wrangling both Zoom participants and students in a distanced classroom is a logistical nightmare, and also seems like it would be an all-around lower quality education than if instructors were allowed to dive in to making solid online curricula. Its also very difficult for instructors to plan for classes when schools havent made decisions on schedules and course delivery methods; university leadership is acting as if they can make a last minute decision and faculty can accommodate anything, whereas in reality, it takes time to create an excellent online course.

All around, students are not being well served by many current university plans. This leads to the question of who benefits from these convoluted reopening schemes. University budgets, like other economic sectors, are hurting from the pandemic. However, leading students to feel like theyre being exploited and put at risk for their tuition dollars is unacceptable. On the other hand, a handful of universities (such as the University of Vermont) are genuinely trying to have a conversation with their communities and find what options will best support students, an example that more institutions should follow.

Many of the university plans give information on what undergraduate students can expect for fall and how they will be offered the courses they need to finish their degree. However, these same plans often leave out graduate students, especially student workers (e.g. teaching assistants (TAs) and graduate researchers). Graduate students are in a unique position of being not quite just a student, but not quite an employee either; as a result, university plans are uniquely hard to navigate for graduate students. For example, West Virginia University has a FAQs page for faculty and one for studentswhere would grad students fall in that categorization?

One of the biggest issues facing graduate students is TAs being forced to teach in-person classes, face-to-face with many students, unless they have a specific medical exemption. Given the power dynamics of graduate school, even under normal circumstances its often difficult for students to challenge departmental decisions without risk of hurting their futures in academia; now, its literally life or death, as some universities will rescind pay and healthcare benefits from TAs not willing to risk teaching or holding office hours in-person.

For those who do end up teaching in campus classrooms, its unclear how much of the burden of safety enforcement will fall on instructors. With no clear plans for how mask wearing, social distancing, and symptom monitoring will be enforced, there is a risk that these responsibilities will fall to those, especially TAs, who are already vulnerable in classrooms and dont have a lot of power to ensure compliance. Some universities omitted detailed guidance for graduate student researchers, expecting them to return to campus and make safety plans with their individual departments or even their individual advisors. Although allowing departments and research groups to make their own safety decisions allows for flexibility to fit each individual situation, it also leaves graduate student researchers without important protections for their health and job security.

For graduate students in particular, theres the additional stress of not only being an employee, but also having to make progress towards a degree. Qualifying and comprehensive exams and PhD defenses, extremely stressful exams even in normal times, are now being moved online, forcing students to prepare for and take these exams while dealing with the additional hurdles of working-from-home and stresses from dealing with the pandemic. Students are working with overburdened advisors who are juggling their usual responsibilities while being at home with their families, plus having more faculty meetings than usual to plan for the uncertain future. The additional stress of the pandemic has impacted student mental health, especially for graduate students who already face a multitude of mental health problems. A few departments, like WVUs Physics department, have made adjustments to degree schedules, essentially stopping the clock on qualifying exam timelines to acknowledge that we are in a unique time and should not try to proceed as usual given the circumstances. Similarly, UCLAs Astronomy Division delayed comprehensive exams to accommodate how students needed extra time to prepare due to the effects of the pandemic.

Overall, graduate students are grappling with uncertainty on all frontsin the courses theyre taking, their research work, the classes they teach, their degree milestones, their health in this pandemic, and even their future career prospects.

Undergraduate students, graduate students, faculty and staff have been (or will be) negatively affected by many of the policies laid out by universities attempting to bring us back to a state of pre-pandemic normalcy. The authors of this piece strongly believe we would all be better off if we acknowledged our current situation and adapted to it instead of forcing things to resemble the pre-pandemic world, a world which simply no longer exists. Universities must do better, and create realistic plans based on the safety and wellbeing of their undergraduates, grad students, faculty, and staff.

Information on school plans for Fall 2020, when not otherwise linked, was sourced from communication with graduate students who wish to remain anonymous.

Beyond astro-ph articles are not necessarily intended to be representative of the views of the entire Astrobites collaboration, nor do they represent the views of the AAS or all astronomers. While AAS supports Astrobites, Astrobites is editorially independent and content that appears on Astrobites is not reviewed or approved by the AAS.

Thank you to the other members of the Astrobites team who helped make this piece possibleespecially Haley Wahl, Sanjana Curtis, Ellis Avallone, and Jenny Calahan!

About Briley LewisBriley Lewis is a second-year graduate student and NSF Fellow at the University of California, Los Angeles studying Astronomy & Astrophysics. Her research interests are primarily in planetary systems both exoplanets and objects in our own solar system, how they form, and how we can create instruments to learn more about them. She has previously pursued her research at the American Museum of Natural History in NYC, and also at Space Telescope Science Institute in Baltimore, MD. Outside of research, she is passionate about teaching and public outreach, and spends her free time bringing together her love of science with her loves of crafting and writing.

View original post here:

COVID-19 in Fall 2020: A Concerning Situation for Students - Astrobites

Buried Monsters of the Early Universe Unveiled By the Deepest X-Ray Image Ever Taken – The Daily Galaxy –Great Discoveries Channel

Posted on Jul 16, 2020 in Astronomy, Black Holes

With our new identifications weve found a bunch of heavily obscured black holes that had previously been missed, said astrophysicist Erini Lambrides of Johns Hopkins University (JHU) in Baltimore, Maryland, about the discovery of a type of growing supermassive black hole formed billions of years ago masquerading as another using a survey known as the Chandra Deep Field-South (CDF-S), the deepest X-ray image ever taken (above).

The CDF-S contains the highest concentration of black holes ever seen, equivalent to 5,000 over the area on the sky covered by the full Moon. The true identity of these black holes the ultimate extreme of a moment in timehelps solve a long-running mystery in astrophysics.

Supermassive black holes grow by pulling in surrounding material, which is heated and produces radiation at a wide range of wavelengths including X-rays, including a phase, which happened billions of years ago, when a dense cocoon of dust and gas covers most black holes. These cocoons of material are the fuel source that enables the black hole to grow and generate radiation.

Hidden in Cocoons

Based on the current picture held by astronomers many black holes buried in heavily obscured cocoons should exist, but are notoriously difficult to find, reports the Chandra X-Ray Observatory. Until now the observed number has fallen short of predictionseven in the deepest images like the CDF-S.

With our new identifications weve found a bunch of heavily obscured black holes that had previously been missed, said Lambrides who led the study. We like to say we found these giant black holes, but they were really there all along.

Unveiled Over 80 Days

The latest study combined over 80 days of Chandra observing time in the CDF-S with large amounts of data at different wavelengths from other observatories, including NASAs Hubble Space Telescope and NASAs Spitzer Space Telescope. The team looked at black holes located 5 billion light years or more away from Earth. At these distances, scientists had already found 67 heavily obscured, growing black holes with both X-ray and infrared data in the CDF-S. In this latest study, the authors identified another 28.

Gargantuan Filaments Incubators of Supermassive Black Holes in Early Cosmos

These 28 supermassive black holes were previously categorized differentlyeither as slowly growing black holes with low density or nonexistent cocoons, or as distant galaxies.

A Case of Mistaken Identity

This could be considered a case of mistaken black hole identity, said co-author Marco Chiaberge of Space Telescope Science Institute in Baltimore, Maryland, but these black holes are exceptionally good at hiding exactly what they are.

Lambrides and her colleagues compared their data with expectations for a typical growing black hole. Using data from all of the wavelengths except for X-rays, they predicted the amount of X-rays they should be detecting from each black hole. The researchers found a much lower level of X-rays than they expected from 28 sources, which implies that the cocoon around them is about ten times denser than scientists previously estimated for these objects.

Supermassive Black Holes Could Actually Be Enigmatic Dark-Energy Objects

Taking the higher density of the cocoon into consideration, the team showed that the misidentified black holes are producing more X-rays than previously thought, but the denser cocoon prevents most of these X-rays from escaping and reaching the Chandra telescope. This implies they are growing more quickly.

Previous groups did not apply the analysis technique adopted by Lambrides and her team, nor did they use the full set of data available for the CDF-S, giving them little information about the density of the cocoons.

A Uniform Glow

These results are important for theoretical models estimating the number of black holes in the universe and their growth rates, including those with different amounts of obscuration (in other words, how dense their cocoons are). Scientists design these models to explain a uniform glow in X-rays across the sky called the X-ray background, first discovered in the 1960s. Individual growing black holes observed in images like the CDF-S account for most of the X-ray background.

The X-ray background not currently resolved into individual sources is dominated by X-rays with energies above the threshold that Chandra can detect. Heavily obscured black holes are a natural explanation for this unresolved component because lower-energy X-rays are absorbed by the cocoon more than high-energy ones, and therefore are less detectable. The additional heavily obscured black holes reported here help reconcile past differences between the theoretical models and observations.

Slowly Coming into Focus

Its like the X-ray background is a blurry picture that has been slowly coming into focus for decades, said co-author Roberto Gilli from the National Institute of Astrophysics (INAF) in Bologna, Italy. Our work has involved understanding the nature of the objects that have been some of the last to be resolved.

In addition to helping explain the X-ray background, these results are important for understanding the evolution of supermassive black holes and their host galaxies. The masses of galaxies and their supermassive black holes are correlated with each other, meaning that the more massive the galaxy the more massive the black hole.

A paper reporting the results of this study is being published in The Astrophysical Journal. The other authors of the paper are Timothy Heckman of JHU; Fabio Vito from Pontificia Universidad Catlica de Chile, in Santiago, Chile; and Colin Norman from JHU.

Source: A Large Population of Obscured AGN in Disguise as Low Luminosity AGN in Chandra Deep Field South, arxiv.org/abs/2002.00955

The Daily Galaxy, Max Goldberg, via Chandra X-Ray Center

More here:

Buried Monsters of the Early Universe Unveiled By the Deepest X-Ray Image Ever Taken - The Daily Galaxy --Great Discoveries Channel

Dying Stars and Stellar Winds Breathe Life Into Earth – SciTechDaily

As dying stars take their final few breaths of life, they gently sprinkle their ashes into the cosmos through the magnificent planetary nebulae. These ashes, spread via stellar winds, are enriched with many different chemical elements, including carbon.

Findings from a study published on July 6, 2020, in Nature Astronomy show that the final breaths of these dying stars, called white dwarfs, shed light on carbons origin in the Milky Way.

The findings pose new, stringent constraints on how and when carbon was produced by stars of our galaxy, ending up within the raw material from which the Sun and its planetary system were formed 4.6 billion years ago, says Jeffrey Cummings, an Associate Research Scientist in the Johns Hopkins Universitys Department of Physics & Astronomy and an author on the paper.

NGC 7789, also known as Carolines Rose, is an old open star cluster of the Milky Way, which lies about 8,000 light-years away toward the constellation Cassiopeia. It hosts a few White Dwarfs of unusually high mass, analyzed in this study. Credit: Guillaume Seigneuret and NASA

The origin of carbon, an element essential to life on Earth, in the Milky Way galaxy is still debated among astrophysicists: some are in favor of low-mass stars that blew off their carbon-rich envelopes by stellar winds became white dwarfs, and others place the major site of carbons synthesis in the winds of massive stars that eventually exploded as supernovae.

Using data from the Keck Observatory near the summit of Mauna Kea volcano in Hawaii collected between August and September 2018, the researchers analyzed white dwarfs belonging to the Milky Ways open star clusters. Open star clusters are groups of up to a few thousand stars held together by mutual gravitational attraction.

From this analysis, the research team measured the white dwarfs masses, and using the theory of stellar evolution, also calculated their masses at birth.

The connection between the birth masses to the final white dwarf masses is called the initial-final mass relation, a fundamental diagnostic in astrophysics that contains the entire life cycles of stars. Previous research always found an increasing linear relationship: the more massive the star at birth, the more massive the white dwarf left at its death.

But when Cummings and his colleagues calculated the initial-final mass relation, they were shocked to find that the white dwarfs from this group of open clusters had larger masses than astrophysicists previously believed. This discovery, they realized, broke the linear trend other studies always found. In other words, stars born roughly 1 billion years ago in the Milky Way didnt produce white dwarfs of about 0.60-0.65 solar masses, as it was commonly thought, but they died leaving behind more massive remnants of about 0.7 0.75 solar masses.

The researchers say that this kink in the trend explains how carbon from low-mass stars made its way into the Milky Way. In the last phases of their lives, stars twice as massive as the Milky Ways Sun produced new carbon atoms in their hot interiors, transported them to the surface and finally spread them into the surrounding interstellar environment through gentle stellar winds. The research teams stellar models indicate that the stripping of the carbon-rich outer mantle occurred slowly enough to allow the central cores of these stars, the future white dwarfs, to grow considerably in mass.

The team calculated that stars had to be at least 1.5 solar masses to spread its carbon-rich ashes upon death.

The findings, according to Paola Marigo, a Professor of Physics and Astronomy at the University of Padova and the studys first author, helps scientists understand the properties of galaxies in the universe. By combining the theories of cosmology and stellar evolution, the researchers expect that bright carbon-rich stars close to their death, like the progenitors of the white dwarfs analyzed in this study, are presently contributing to the light emitted by very distant galaxies. This light, which carries the signature of newly produced carbon, is routinely collected by the large telescopes from space and Earth to probe the evolution of cosmic structures. Therefore, this new understanding of how carbon is synthesized in stars also means having a more reliable interpreter of the light from the far universe.

###

Reference: Carbon star formation as seen through the non-monotonic initialfinal mass relation by Paola Marigo, Jeffrey D. Cummings, Jason Lee Curtis, Jason Kalirai, Yang Chen, Pier-Emmanuel Tremblay, Enrico Ramirez-Ruiz, Pierre Bergeron, Sara Bladh, Alessandro Bressan, Lo Girardi, Giada Pastorelli, Michele Trabucchi, Sihao Cheng, Bernhard Aringer and Piero Dal Tio, 6 July 2020, Nature Astronomy.DOI: 10.1038/s41550-020-1132-1

This study was funded by the European Research Council Consolidator Grant (project STARKEY, 615604) and the European Unions Horizon 2020 research and innovation program (677706-WD3D).

Other authors on this study include Jason Kalirai and Sihao Cheng of the Johns Hopkins University; Jason Lee Curtis of the American Museum of Natural History; Yang Chen and Bernhard Aringer of the University of Padova; Pier-Emmanuel Tremblay of the University of Warwick; Enrico Ramirez-Ruiz of the University of California, Santa Cruz; Pierre Bergeron of the Universit de Montral; Sara Bladh of Uppsala University; Alessandro Bressan of the International School for Advanced Studies; Lo Girardi of the Astronomical Observatory of Padova-INAF; Giada Pastorelli of the Space Telescope Science Institute; and Michele Trabucchi and Piero Dal Tio of the University of Geneva.

Visit link:

Dying Stars and Stellar Winds Breathe Life Into Earth - SciTechDaily

Spectacular sight of five planets together to be seen in Karachi at midnight – Geo News

KARACHI: Five planets of the solar system would be visible together at 12am tonight in the city sky, a topplanetary scientist announced on Sunday.

The five planets that can be viewed simultaneously tonight include Mercury, Venus, Mars, Jupiter, and Saturn, according to Prof Dr Muhammad Jawed Iqbal, the director at the Institute of Space and Planetary Astrophysics (ISPA) a research facility at the University of Karachi.

"It will be possible to see the five planets together at midnight and all five can be seen without binoculars," Dr Iqbal said. "Usually, two to three planets are visible in the night sky."

The scientist noted that the coming together of the planets would be available for viewing for the next few nights. However, it would be difficult to see the interesting activity in the sky due to Karachi's current cloudy weather.

It is interesting to note that at the same time, Mercury will be in retrograde (apparent motion of moving backwards) for the second time this year, from June 18 to July 12, 2020, according to Forbes. Furthermore, the ringed Saturn would bebrightest at night on July 20, the publication added, as it would reach opposition.

Here is the original post:

Spectacular sight of five planets together to be seen in Karachi at midnight - Geo News

Solar Orbiter Captures Closest Images of the Sun; Reveals Presence of Millions of ‘Campfires’ – The Weather Channel

Solar Orbiter spots campfires on the Sun. Locations of campfires are annotated with white arrows.

NASA and ESA have released the first images of the Solar Orbiter, including the closest pictures ever taken of the Sun. These images were captured when the spacecraft completed its first close pass of the Sun in mid-June this year.

These unprecedented pictures of the Sun are the closest we have ever obtained, said Holly Gilbert, NASA project scientist for the mission at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

He further added: These amazing images will help scientists piece together the Suns atmospheric layers, which is important for understanding how it drives space weather near the Earth and throughout the solar system.

Launched on February 10, 2020, the Solar Orbiter mission has carried several cutting-edge instruments to monitor the environment of the Earths closest star. Aboard the Orbiter are six remote-sensing instruments, or telescopes, to snap images of the Sun and its surroundings, along with four other in-situ instruments.

Through this mission, scientists aim to gain an in-depth understanding of the solar wind, and how it releases the stream of charged particles that influence the entire Solar System.

The first images from the mission detail the presence of millions of miniature-size solar flaresalso referred to as 'campfires'near the surface of the Sun. NASA describes solar flares as sudden explosions of energy caused by the tangling, crossing, or reorganising of magnetic field lines near sunspots.

The images were captured by the Extreme Ultraviolet Imager (EUI) on May 30, 2020, from a distance of 77 million km from the Sun. During this time, the Solar Orbiter was at the periheliona point in its elliptical orbit measured to be closest to the Sunwhich is roughly half the distance between the Earth and the Sun.

The EUI is programmed to take high-resolution images of the solar coronathe outermost layer of the Suns atmospherewhich usually remains unexposed due to the bright light of the Suns surface and is, therefore, difficult to capture.

The campfires are little relatives of the solar flares that we can observe from Earth, million or billion times smaller, said David Berghmans of the Royal Observatory of Belgium (ROB), Principal Investigator of the EUI instrument in an official statement. The Sun might look quiet at first glance, but when we look in detail, we can see those miniature flares everywhere we look, he added.

Meanwhile, space scientists are still trying to understand if these campfires are just smaller versions of solar flares or a different phenomenon altogether.

Scientists have, however, hypothesised that these campfires may be the reason behind coronal heating. The corona layer is the part of Suns upper atmosphere, which burns at temperature worth millions of degrees. This layer also extends to millions of kilometres into the outer space.

With the help of more Orbiter data, scientists are aiming to demystify the mysterious coronal heating phenomenon and figure out what causes the corona to be so hota problem considered to be among the most vexing in astrophysics.

**

For weather, science & COVID-19 updates on the go, download The Weather Channel App (on Android and iOS store). It's free!

Read more from the original source:

Solar Orbiter Captures Closest Images of the Sun; Reveals Presence of Millions of 'Campfires' - The Weather Channel

New study of oldest light confirms age of the universe Tunis Daily News – Tdnews

The age of the universe is around 13.8 billion years, an international team of astrophysicists has said in a study published Wednesday.

From a mountain high in Chiles Atacama Desert, astronomers with the National Science Foundations Atacama Cosmology Telescope have taken a fresh look at the oldest light in the universe. Their new observations, plus a bit of cosmic geometry, suggest that the universe is 13.77 billion years old, give or take 40 million years.

The new estimate matches the one provided by the standard model of the universe and measurements of the same light made by the Planck satellite, a space-based observatory that ran from 2009-2013.

This adds a fresh twist to an ongoing debate in the astrophysics community, said Simone Aiola, first author of one of two new papers on the findings posted July 15 to arXiv.org. The trouble is that research teams measuring the movements of galaxies have calculated that the universe is hundreds of millions of years younger than the Planck team predicted. That discrepancy suggested that a new model for the universe might be needed, and sparked concerns that one of the sets of measurements might be incorrect.

Now weve come up with an answer where Planck and the Atacama Cosmology Telescope agree, said Aiola, a researcher at the Flatiron Institutes Center for Computational Astrophysics in New York City. It speaks to the fact that these difficult measurements are reliable.

The age of the universe also reveals how fast the cosmos is expanding, a number called the Hubble constant. The Atacama measurements suggest a Hubble constant of 67.6 kilometers per second per megaparsec. This result agrees almost exactly with the previous estimate of 67.4 by the Planck satellite team, but its slower than the 74 inferred from the measurements of galaxies.

Making this independent measurement is really exciting because theres a mystery in the field, and this helps us sharpen our understanding of that mystery, said Jeff McMahon, an associate professor of astronomy and astrophysics at the University of Chicago who led the design of the detectors and other new technologies used to make this measurement. This confirms the ongoing discrepancy. And we still have much more data to analyze, so this is just the beginning.

The close agreement between the Atacama Cosmology Telescope and Planck results and the standard cosmological model is bittersweet, Aiola said: Its good to know that our model right now is robust, but it would have been nice to see a hint of something new. Still, the disagreement with the 2019 study of the motions of galaxies maintains the possibility that unknown physics may be at play, he said.

Like the Planck satellite and its earthbound cousin the South Pole Telescope, the Atacama Telescope peers at the afterglow of the Big Bang. This light, known as the cosmic microwave background, or CMB, marks a time 380,000 years after the universes birth, when protons and electrons joined to form the first atoms. Before that time, the cosmos was opaque to light.

If scientists can estimate how far light from the CMB traveled to reach Earth, they can calculate the universes age. Thats easier said than done, though. Judging cosmic distances from Earth is hard. So instead, scientists measure the angle in the sky between two distant objects, with Earth and the two objects forming a cosmic triangle. If scientists also know the physical separation between those objects, they can use high school geometry to estimate the distance of the objects from Earth.

Subtle variations in the CMBs glow offer anchor points to form the other two vertices of the triangle. Those variations in temperature and polarization resulted from quantum fluctuations in the early universe that got amplified by the expanding universe into regions of varying density. (The denser patches would go on to form galaxy clusters.) Scientists have a strong enough understanding of the universes early years to know that these variations in the CMB should typically be spaced out every billion light-years for temperature and half that for polarization. (For scale, our Milky Way galaxy is about 200,000 light-years in diameter.)

The Atacama Cosmology Telescope measured the CMB fluctuations with unprecedented resolution and sky coverage, taking a closer look at the polarization of the light. The Planck satellite measured the same light, but by measuring its polarization in higher fidelity, the new picture from Atacama reveals more of the oldest patterns weve ever seen, said Suzanne Staggs, the telescopes principal investigator and the Henry deWolf Smyth Professor of Physics at Princeton University.

This measurement was possible thanks to new technology designed and built by McMahons team. Basically, we figured out how to make the detectors measure two colors and to pack as many into each camera as possible, McMahon said. Then we developed new lenses out of metamaterials. (Metamaterials are a type of material thats engineered to produce properties that dont exist naturally.)

From conception to deployment at the telescope to analysis, the process has spanned nearly 10 years, McMahon said. Working with this amazing team to develop this project all the way from concept sketches to producing results at the forefront of cosmology, has been absolutely fantastic.

Sara Simon, now at Fermi National Accelerator Laboratory, made significant contributions to detector design; UChicago graduate student Joey Golec developed methods to fabricate the metamaterial optics; and UChicago graduate student Maya Mallaby-Kay is now working to make the datasets public.

As the Atacama Cosmology Telescope continues making observations, astronomers will have an even clearer picture of the CMB and a more exact idea of how long ago the cosmos began. The team will also scour those observations for signs of physics that doesnt fit the standard cosmological model. Such strange physics could resolve the disagreement between the predictions of the age and expansion rate of the universe arising from the measurements of the CMB and the motions of galaxies.

Were continuing to observe half the sky from Chile with our telescope, said Mark Devlin, the telescopes deputy director and the Reese W. Flower Professor of Astronomy and Astrophysics at the University of Pennsylvania. As the precision of both techniques increases, the pressure to resolve the conflict will only grow.

I didnt have a particular preference for any specific value it was going to be interesting one way or another, said Cornell Universitys Steve Choi, first author of the other paper posted to arXiv.org. We find an expansion rate that is right on the estimate by the Planck satellite team. This gives us more confidence in measurements of the universes oldest light.

Read the original here:

New study of oldest light confirms age of the universe Tunis Daily News - Tdnews