Category Archives: Astronomy

Dark matter has a profound effect on our universe, shaping galaxies and even leaving its fingerprints on the energy left over from the Big Bang. Despite its relevance, dark matter is also extremely hard to detect rather than observe it directly, astronomers instead look for clues based on its gravitational interaction with normal matter (the protons, electrons, and neutrons that make up everything we see and touch). Recent observations made with NASAs Chandra X-ray Observatory have hinted that dark matter may be fuzzier than previously thought.

The study, which was recently accepted for publication in the Monthly Notices of the Royal Astronomical Society, focuses on X-ray observations of 13 galaxy clusters. The authors use observations of the hot gas that permeates galaxy clusters to estimate the amount and distribution of dark matter within the clusters and test its properties against current leading models, looking for the model that best fits the data.

The current standard cosmological model includes cold dark matter as a major component. In this case, cold simply means that dark matter travels slowly when compared to the speed of light. However, cold dark matter models indicate that dark matter and normal matter, which is drawn to the dark matter via gravity should clump together in the centers of galaxies. But no such increase in matter, normal or dark, is seen. Additionally, cold dark matter models predict that the Milky Way should have many more small satellite galaxies than we currently see. Even accounting for the fact that some satellites may be challenging to find, the cold dark matter models still over-predict our satellites by a considerable amount.

However, cold dark matter is only one of several dark matter theories. By contrast, fuzzy dark matter is a model in which dark matter has a mass about 10 thousand trillion trillion times smaller than an electron. In quantum mechanics, all particles have both a mass and a corresponding wavelength. Such a tiny mass would actually cause the wavelength of dark matter to stretch 3,000 light-years between peaks. (The longest wavelength of light, which is radio, stretches just a few miles between peaks.)

With a wavelength this long, dark matter would not clump in the centers of galaxies, which could explain the reason this is not observed. But while simple fuzzy dark matter models fit observations of small galaxies, larger galaxies may require a slightly more complex explanation. And galaxy clusters are larger test beds still, which is why researchers turned Chandra to several massive galaxy clusters for observations.

The results show that while a simple fuzzy dark matter model still didnt explain the cluster observations well, a more complex and fuzzier model did. In this model, dark matter occupying several quantum states at once (think an atom with many electrons, some of which are at higher energy levels) creates overlapping wavelengths that further spread out the effect, which changes the distribution of dark matter expected throughout the galaxy cluster as a whole.

The predictions from this model match the observations of the 13 galaxy clusters much more closely, indicating that fuzzier dark matter may be the best model to incorporate into our cosmological models. However, further study and more precise measurements are needed to better test this theory and ensure it truly reflect what we see throughout the cosmos.

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Dark matter may be fuzzier than we thought - Astronomy Magazine

Todays astronomers dont really look at stars or galaxies so much as images produced from data generated by light. If that same data were used to produce 3-D printouts, tactile displays or sound, would it open the study and pursuit of astronomy to the blind and visually impaired?

Thats the kind of question the University of Chicagos Yerkes Observatory and its partners will try to answer with the help of a $2.5 million National Science Foundation grant. Over the next three years, they will develop Afterglow Accessnew software that will make astronomy more accessible to the blind and visually impaired.

Amazing pictures of stars start as numbers on a spreadsheet, and those numbers can be manipulated and presented in myriad ways, said Kate Meredith, director of education outreach at the Yerkes Observatory and the education lead of Innovators Developing Accessible Tools for Astronomy, a new research initiative from the observatory. We wont consider ourselves successful unless within three years we have developed new computer tools with and for the blind and visually impaired that can be used in real applications, learning situations and scholarly research.

The National Federation of the Blind estimates that more than seven million Americans are visually disabled. Unequal access to quantitative information and the lack of vision-neutral tools presents them with barriers to study and master astronomy and other STEM subjects, Meredith said.

To overcome this, the Yerkes research initiative will engage blind and visually impaired students as well as sighted students and their teachers from mainstream and specialized schools for the blind. Twenty teachers and 200 eighth- through 12th-grade students are expected to participate annually. Recruiting teachers and students began this spring. While half of the participating schools will be located in southern Wisconsin and the Chicago area, the remaining schools will be selected from across the United States and its territories.

Students and teachers will participate in user-centered design and universal design processes to develop and test software and learning modules and to improve accessibility aspects of astronomy tools for educational and professional purposes. The project builds upon the success of prior National Science Foundation-supported research projects, including the development of Afterglow; Quorum, an accessible programming language; and the Skynet Junior Scholars, a program that supports collaborative astronomy investigations by young explorers using Skynets international network of telescopes.

The research will advance knowledge about student learning related to computational thinking, the role of computation in astronomy and software design. In addition, it will help determine how participation influences student attitudes and beliefs about who can engage in computing and STEM subjects.

Teaming up blind and visually impaired students with sighted students, teachers and professionals in the design and development of astronomy software and instructional modules will create powerful educational experiences, encourage STEM learning, and lower the barrier-to-entry for blind and visually impaired individuals interested in astronomy and related careers, Meredith said.

Investigators in the program include employees at the University of Chicago; Yerkes Observatory; Associated Universities Inc.; the Technical Education Research Center at the University of Nevada, Las Vegas; and Skynet at the University of North Carolina at Chapel Hill.

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Students, teachers craft software to make astronomy accessible to the blind - UChicago News