Supermassive black holes reside at the center of most, if not all, massive galaxies. Astronomers recently discovered a supermassive black hole that “burps”.

It lies approximately 900 million light-years from Earth, in a galaxy called SDSS J1354+1327 (J1354 for short).

The work, presented at the Washington, D.C., meeting by Julie Comerford of the University of Colorado and published November 6 in The Astrophysical Journal, identifies two separate burps. One ancient burp on the verge of dissipating and one hinting at a much more recent meal.

This is the first time that astronomers identify two separate events in a single galaxy.

The Discovery

For this discovery, Dr. Julie Comerford from the University of Colorado at Boulder and colleagues used observations from NASA’s Chandra X-ray Observatory and the NASA/ESA Hubble Space Telescope, as well as the W.M. Keck Observatory in Mauna Kea, Hawaii, and the Apache Point Observatory near Sunspot, New Mexico.

Chandra detected a bright, point-like source of X-ray emission from J1354. It is a telltale sign of the presence of an extremely massive black hole.

Gas heated to millions of degrees by the enormous gravitational and magnetic forces near the black hole produces these X-rays.

However, researchers combined the data from these different images. Thus, they spotted a large, diffuse “cone” of gas extending 30,000 light years below the bulge of the galaxy. The bulge is where the black hole lies.

To the north, they found evidence for a shock wave, similar to a sonic boom. It lies about 3,000 light years from the black hole. This suggests that a burp occurred after a different clump of gas had been consumed roughly 100,000 years later.

The X-ray data also show that the supermassive black hole is embedded in a heavy veil of gas.

So, by observing optical data, astronomers conclude that the supermassive black hole might have consumed, or accreted, large amounts of gas while blasting off an outflow of high-energy particles. The outflow eventually switched off then turned back on about 100,000 years later.

What do we learn from this?

This is strong evidence that accreting black holes can switch their power output off and on again over timescales that are a blink of an eye to the 13.8 billion-year age of the Universe.

“We are seeing this object feast, burp and nap, and then feast and burp once again, which theory had predicted,” Dr. Comerford said.

“Fortunately, we happened to observe this galaxy at a time when we could clearly see evidence for both events.”

So, Dr. Comerford and co-authors concluded that clumps of material from the companion galaxy swirled toward the center of J1354. Then the supermassive black holes ate them.

“This galaxy really caught us off guard,” said co-author Rebecca Nevin, a doctoral student at the University of Colorado at Boulder.

“We were able to show that the gas from the northern 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 outflow from the black hole.”

paper on the subject was published in the November 6, 2017, issue of the Astrophysical Journal and is available online at

Thumbnail image: This image shows the SDSS J1354+1327 galaxy in a composite image with data from Chandra (purple), and Hubble (red, green and blue). The inset box contains a close-up view of the central region around SDSS J1354+1327’s supermassive black hole. The larger companion galaxy, SDSS J1354+1328, is at the north. Credit: NASA / CXC / University of Colorado / STScI/ J. Comerford et al.