{"id":4224,"date":"2010-01-05T09:17:00","date_gmt":"2010-01-05T09:17:00","guid":{"rendered":"http:\/\/euvolution.com\/futurist-transhuman-news-blog\/massive-black-hole-implicated-in-stellar-destruction\/"},"modified":"2010-01-05T09:17:00","modified_gmt":"2010-01-05T09:17:00","slug":"massive-black-hole-implicated-in-stellar-destruction","status":"publish","type":"post","link":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/space-station\/massive-black-hole-implicated-in-stellar-destruction.php","title":{"rendered":"Massive Black Hole Implicated in Stellar Destruction"},"content":{"rendered":"
\"Composite<\/a>New results from NASA<\/a>'s Chandra X-ray Observator<\/span>y and the Magellan telescopes<\/span> suggest that a dense stellar remnant has been ripped apart by a black hole<\/span> a thousand times as massive as the Sun<\/span>. If confirmed, this discovery would be a cosmic double play: it would be strong evidence for an intermediate mass black hole<\/span>, which has been a hotly debated topic, and would mark the first time such a black hole has been caught tearing a star apart.

This scenario is based on Chandra observations<\/span>, which revealed an unusually luminous source of X-rays in a dense cluster of old stars, and optical observations that showed a peculiar mix of elements associated with the X-ray emission<\/span>. Taken together, a case can be made that the X-ray emission<\/span> is produced by debris from a disrupted white dwarf star that is heated as it falls towards a massive black hole<\/span>. The optical emission comes from debris further out that is illuminated by these X-rays.<\/p>

The intensity of the X-ray emission<\/span> places the source in the \"ultraluminous X-ray source<\/span>\" or ULX category<\/span>, meaning that it is more luminous than any known stellar X-ray source<\/span>, but less luminous than the bright X-ray sources (active galactic nuclei) associated with supermassive black holes<\/span> in the nuclei of galaxies. The nature of ULXs <\/span>is a mystery, but one suggestion is that some ULXs <\/span>are black holes with masses between about a hundred and several thousand times that of the Sun, a range intermediate between stellar-mass black holes<\/span> and supermassive black holes<\/span> located in the nuclei of galaxies.<\/p>

This ULX <\/span>is in a globular cluster, a very old and crowded conglomeration of stars. Astronomers <\/span>have suspected that globular clusters could contain intermediate-mass black holes, but conclusive evidence for this has been elusive.<\/p>

\"Astronomers have made cases for stars being torn apart by supermassive black holes<\/span> in the centers of galaxies before, but this is the first good evidence for such an event in a globular cluster,\" said Jimmy Irwin of the University of Alabama who led the study.<\/p>

Irwin and his colleagues obtained optical spectra of the object using the Magellan I and II telescopes <\/span>in Las Campanas, Chile. These data reveal emission from gas rich in oxygen and nitrogen but no hydrogen, a rare set of signals from globular clusters. The physical conditions deduced from the spectra suggest that the gas is orbiting a black hole of at least 1,000 solar masses<\/span>. The abundant amount of oxygen and absence of hydrogen indicate that the destroyed star was a white dwarf, the end phase of a solar-type star that has burned its hydrogen leaving a high concentration of oxygen. The nitrogen seen in the optical spectrum remains an enigma.<\/p>

\"We think these unusual signatures can be explained by a white dwarf that strayed too close to a black hole and was torn apart by the extreme tidal forces,\" said coauthor Joel Bregman<\/span> of the University of Michigan.<\/p>

Theoretical work suggests that the tidal disruption-induced X-ray emission could stay bright for more than a century, but it should fade with time. So far, the team has observed there has been a 35 percent in X-ray emission from 2000 to 2008.<\/p>

The ULX <\/span>in this study is located in NGC 1399<\/span>, an elliptical galaxy about 65 million light years from Earth<\/span>.<\/p>

Irwin presented these results at the 215th meeting of the American Astronomical Society in Washington, DC. NASA's Marshall Space Flight Center<\/span> in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate<\/span> in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.<\/p>

More information, including images and other multimedia, can be found at:<\/p>

<\/p><\/span> http:\/\/chandra.harvard.edu<\/a>

<\/p><\/span>View my blog's last three great articles....
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