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Chandra Press Room

November 22, 2010
Astronomers using NASA's Chandra X-ray Observatory have found evidence for the youngest black hole known in our cosmic neighborhood - a mere 30 years old -- that provides a unique opportunity to watch a black hole develop during its infancy. The object could help scientists better understand how massive stars explode, which ones leave behind black holes or neutron stars, and how many black holes are in our galaxy and others.

The object is a remnant of SN 1979C, a supernova in the galaxy M100 that, which lies 50 million light years from Earth. Data from Chandra, as well as NASA's Swift, the European Space Agency's XMM- Newton and the German ROSAT observatory revealed a bright source of X- rays that has remained steady during 12 years of observation, from 1995 to 2007. This suggests that the object is a black hole being fed either by material falling into it from the supernova, or else a binary companion.

"If our interpretation is correct, this is the nearest example where the birth of a black hole has been observed," said Daniel Patnaude of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. who led the study.

The scientists think that SN1979C -- first discovered by an amateur astronomer in 1979 -- formed when a star about 20 times more massive than the Sun collapsed. Many new black holes in the distant Universe have previously been detected in the form of gamma-ray bursts (GRBs). However, SN 1979C is different because it is much closer and belongs to a class of supernovas that are unlikely to be associated with a GRB. Theory predicts that, in fact, most black holes in the Universe should form when the core of a star collapses and a GRB is not produced. It formed from a particular type of supernova that would not result in a gamma-ray burst (GRB), by which many new black holes in the distant Universe have been detected. Recent theories suggest that most black holes do not emit GRBs, though an example has not been seen until now.

"This may be the first time that the common way of making a black hole has been observed," said coauthor Abraham Loeb, also of the Harvard-Smithsonian Center for Astrophysics. "However, it is very difficult to detect this type of black hole birth because decades of X-ray observations are needed to make the caseMost black holes in the Universe should form when the core of a star collapses and a gamma-ray burst is not produced."

The idea of a black hole with an observed age of only about 30 years is consistent with some recent theoretical work. In 2005, a theory was presented by Tim Young, of the University of North Dakota, that the bright optical light of this supernova was powered by a jet from a black hole that was unable to penetrate the hydrogen envelope of the star to form a GRB. The results seen in the observations of SN 1979C fit this theory very well.

Although the evidence points to a newly formed black hole in SN 1979C, another intriguing possibility is that a young, rapidly spinning neutron star with a powerful wind of high energy particles could be responsible for the X-ray emission. This would make the object in SN 1979C the youngest and brightest example of such a "pulsar wind nebula" and the youngest known neutron star. The Crab pulsar, the best- known example of a bright pulsar wind nebula, is about 950 years old.

"It's very rewarding to see how the commitment of some of the most advanced telescopes in space, like Chandra, can help complete the story," said Jon Morse, head of the Astrophysics Division at NASA's Science Mission Directorate.

These results will appear in the New Astronomy journal in a paper by Patnaude, Loeb, and Christine Jones (Harvard-Smithsonian Center for Astrophysics.) NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

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