You’ll Never Guess What a Supermassive Black Hole’s Favorite Food Is

Researchers are beginning to understand the relationship between black holes and galaxies. 

 

Cosmic jellyfish might sound like the name of a really bad cover band, but in reality, these are galaxies whose tentacles of stars, gases, and cosmic dust stream forth from their central, galactic discs. They certainly aren’t alone. Curiosities and strange wonders abound in our vast, prodigious universe. Both professional and amateur astronomers alike have hollered “Eureka!” at such things as voorwerps, magnetars, blitzars, and “green peas.”


What else is interesting about jellyfish galaxies? Funny you should ask. The European Southern Observatory (ESO) has recently discovered that they fuel supermassive black holes. These enormous whirling vortexes each contain an “active galactic nucleus (AGN).” The AGN is the ultra-bright region at the center of a galaxy.

Although supermassive black holes inhabit the center of almost all galaxies, few are active. Exactly why has been a big question for astronomers. Another question is how galaxies accrete or gain matter.

Artist's rendition of a supermassive black hole. By ESO, via Wikimedia Commons.

Astronomers at ESO’s Paranal Observatory in Chile recently found out how AGNs accrete. Their report was published in the journal Nature. By using their MUSE (Multi-Unit Spectroscopic Explorer) instrument, part of the Very Large Telescope (VLT), the team found that a supermassive black hole sits at the heart of each jellyfish galaxy.

Newborn stars produce tentacles. Some of the gases are fed back into the galaxy’s center, causing its supermassive black hole to glow and shine in a way that few others do. To conduct the study, researchers observed nearby jellyfish galaxies, some with tentacles tens of thousands of light-years long.

The project was led by Bianca Poggianti of the INAF-Astronomical Observatory in Italy. She and colleagues discovered that these celestial appendages are formed through what’s known as ram pressure stripping. Gravity pulls galaxies close together at high speed, forming clusters. The intensity of this force demands a close proximity, which in turn causes a buildup of hot gases.

The gases soon become dense. The pressure builds and after awhile, it becomes too great. Once it reaches critical mass, starbursts go off within the galaxy’s core, sending gas-filled jets spewing out. From our vantage point, these jets look like tentacles. So it seems like some of these gases in the tentacles make their way back to the AGN, which how galaxies accrete useful material.

“This strong link between ram pressure stripping and active black holes was not predicted and has never been reported before,” Dr. Poggianti said. “It seems that the central black hole is being fed because some of the gas, rather than being removed, reaches the galaxy center.”

Poggianti and her team are currently studying many more such galaxies. They’ll look at 114 out of the 400 known cosmic jellyfish out there.

Example of a jellyfish galaxy. ESO.

Dr. Poggianti concludes the report by saying,

This survey, when completed, will reveal how many, and which, gas-rich galaxies entering clusters go through a period of increased activity at their cores. A long-standing puzzle in astronomy has been to understand how galaxies form and change in our expanding and evolving Universe. Jellyfish galaxies are a key to understanding galaxy evolution as they are galaxies caught in the middle of a dramatic transformation.

To see more about the ESO’s discovery, click here: 

NASA astronomer Michelle Thaller on ​the multiple dimensions of space and human sexuality

Science and the squishiness of the human mind. The joys of wearing whatever the hell you want, and so much more.

Flickr / 13winds
Think Again Podcasts
  • Why can't we have a human-sized cat tree?
  • What would happen if you got a spoonful of a neutron star?
  • Why do we insist on dividing our wonderfully complex selves into boring little boxes
Keep reading Show less

How to split the USA into two countries: Red and Blue

Progressive America would be half as big, but twice as populated as its conservative twin.

Image: Dicken Schrader
Strange Maps
  • America's two political tribes have consolidated into 'red' and 'blue' nations, with seemingly irreconcilable differences.
  • Perhaps the best way to stop the infighting is to go for a divorce and give the two nations a country each
  • Based on the UN's partition plan for Israel/Palestine, this proposal provides territorial contiguity and sea access to both 'red' and 'blue' America
Keep reading Show less

Increased air travel may decrease the chances of a global pandemic

The closer together we get, the argument goes, the healthier we'll be.

Surprising Science
  • The more exposed we are to each other, the less surprising a pathogen will be to our bodies.
  • Terrorism, high blood pressure, and staffing issues threaten to derail progress.
  • Pursuing global health has to be an active choice.
Keep reading Show less