New results from the Sloan Digital Sky Survey (SDSS) reveal that a black hole at the center of the quasar SDSS J1011+5442 seems to have disappeared, making the mass of energy undetectable. Although the team of researchers investigating the disappearance know that the black hole is still there, it appears to have consumed all of the gas in its proximity over the past ten years, preventing them from detecting the spectroscopic signature of the quasar.
"This is the first time we've seen a quasar shut off this dramatically, this quickly," Jessie Runnoe, first author of the study, said in a press release.
The team used data from spectrum measurements of SDSS J1011+5442 all the way back in 2003 and compared this data to spectrum measurements in early 2015 and were able to better understand the properties of the gas that was inevitably swallowed by the black hole.
"The difference was stunning and unprecedented," said John Ruan, co-author of the study. "The hydrogen-alpha emission dropped by a factor of 50 in less than twelve years, and the quasar now looks like a normal galaxy." The change was so great that throughout the SDSS collaboration and astronomy community, the quasar became known as a "changing-look quasar."
At the root of every quasar is a giant black hole so big that infalling gas can reach astronomical temperatures upwards of millions of degrees. This hot gas glows so bright that scientists can examine it all the way from Earth. However, in the case of SDSS J1011+5442, the team believes that the quasar expended its glowing-hot gas, which led to its drop in brightness.
"Essentially, it has run out of food, at least for the moment," Runnoe said. "We were fortunate to catch it before and after."
The findings were submitted to the Monthly Notices of the Royal Astronomical Society and the pre-print of the study is available at arXiv.org.
