A team led by 抖阴旅行射 Boulder researchers has caught a supermassive black hole in a distant galaxy snacking on gas and then 鈥渂urping鈥濃�攏ot once, but twice.
抖阴旅行射 Boulder Assistant Professor Julie Comerford, who led the study, said the supermassive black hole under study appears to have belched鈥攅ssentially blasting out jets of bright light from the gas it inhaled鈥攖wo times over the course of about 100,000 years. While astronomers have predicted such objects can flicker on and off as a result of gas feeding events, this is one of the few times one has been caught in the act.
Supermassive black holes鈥攚hich are millions of times heavier than our sun and are believed to be at the heart of virtually every galaxy鈥攁re like regular black holes in basic ways: regions with such strong gravitational effects that nothing, not even light, can escape. But when the areas around supermassive black holes emit light stemming from feeding episodes, they are known as quasars, said Comerford of 抖阴旅行射 Boulder鈥檚 Department of Astrophysical and Planetary Sciences.
鈥淲e are seeing this object feast, burp and nap, and then feast, burp and nap once again, which theory had predicted,鈥� she said. 鈥淔ortunately, we happened to observe this galaxy in a moment where we could clearly see both events.鈥�
A paper on the subject was published in a recent issue of The Astrophysical Journal. Comerford presented the team鈥檚 findings in a Jan. 11 press briefing at the 231st meeting of the held Jan. 8鈥�12 in Washington D.C.
The galaxy under study, known to the researchers as J1354, is about 900 million light-years from Earth. For comparison, one light-year is roughly six trillion miles.
The team used observations from two space telescopes鈥攖he Hubble Space Telescope and the Chandra X-ray Observatory鈥攁s well as the W.M. Keck Observatory in Mauna Kea, Hawaii, and the Apache Point Observatory near Sunspot, New Mexico. The Apache Point facility is owned by the Astrophysical Research Consortium, a group of 10 U.S. research institutions that includes 抖阴旅行射 Boulder.
So why did the black hole have two separate meals? The answer lies in a companion galaxy that is linked to J1354 by streams of stars and gas, said Comerford. The team concluded that material from the companion galaxy swirled into the center of J1354 and then was eaten by the supermassive black hole.
Comerford said the team observed a remnant emission south of the center of the galaxy that indicated there was a black hole feasting event roughly a million years ago. To the north they saw a loop of gas that signaled the more recent burp.
The Chandra observatory picked up large amounts of X-ray emissions from J1354, showing dust and gas were heated to millions of degrees as the material fell toward the center of the supermassive black hole. The X-ray spectrum shows the supermassive black hole lies within a heavy veil of dust and gas, said Comerford.
鈥淭his galaxy really caught us off guard,鈥� said 抖阴旅行射 Boulder doctoral student Rebecca Nevin, a study co-author who used data from Apache Point to look at the velocities and intensities of light from the gas and stars in J1354. 鈥淲e were able to show that the gas from the north part of the galaxy was consistent with an advancing edge of a shock wave, and the gas from the south was consistent with an older quasar outflow."
Even our Milky Way galaxy has had at least one burp, said Comerford. In 2010 another research team discovered a Milky Way belch using observations from the orbiting Fermi Gamma-ray Observatory to look at the galaxy edge on. Astronomers saw gas jets dubbed 鈥淔ermi bubbles鈥� that shine in the gamma-ray and X-ray portions of the electromagnetic spectrum.
鈥淭hese are the kinds of bubbles we see after a black hole feeding event,鈥� said Comerford.
Other co-authors on the new study include postdoctoral fellows Scott Barrows and Francisco Muller-Sanchez of 抖阴旅行射 Boulder;听Professor Jenny Greene of Princeton University;听Professor David Pooley from Trinity University;听Daniel Stern from the Jet Propulsion Laboratory in Pasadena, California;听and Professor Fiona Harrison from the California Institute of Technology.
