Growing old together: A sharper look at black holes and their host galaxies

Growing old together: A sharper look at black holes and their host galaxies
Image from the Romulus simulation depicting the network of structures that assemble on intergalactic scales, revealing where the galaxies hosting black holes form. More massive galaxies that host more massive black holes tend to live in hotter (red) regions, while lower-mass galaxies live in colder (blue) regions and harbor smaller black holes. Credit: Yale University

Some relationships are written in the stars. That's definitely the case for supermassive black holes and their host galaxies, according to a new study from Yale University.

The "special relationship" between (SMBHs) and their hosts—something astronomers and physicists have observed for quite a while—can now be understood as a bond that begins early in a galaxy's formation and has a say in how both the galaxy and the SMBH at its center grow over time, the researchers note.

A black hole is a point in space where matter has been compacted so tightly that it creates intense gravity. This gravity is strong enough that even light can't escape its pull. Black holes can be as small as a single atom or as large as billions of miles in diameter. The biggest are called "supermassive" black holes and have masses equal to that of millions—or even billions—of suns.

SMBHs are often found at the center of large galaxies, including our own galaxy, the Milky Way. Although SMBHs were theoretically expected to exist, the first observational hints were detected in the 1960s; earlier this year, the Event Horizon Telescope released the first silhouette of a black hole in the galaxy Messier 87. Astrophysicists continue to theorize about the origins of black holes, how they grow and glow, and how they interact with in different astronomical environments.

"There has been a lot of uncertainty regarding the SMBH-galaxy connection, in particular whether SMBH growth was more tightly connected to the or the mass of the host galaxy," said Yale astrophysicist Priyamvada Natarajan, senior investigator of the new study, which appears in the journal Monthly Notices of the Royal Astronomical Society. "These results represent the most thorough theoretical evidence for the former—the growth rate of black holes appears to be tightly coupled to the rate at which stars form in the host."

Natarajan has made significant contributions to our understanding of the formation, assembly, and growth of SMBHs, with respect to their environs. Her work speaks to the underlying question of whether these connections are mere correlations or signs of deeper causation.

Natarajan and her team—first author Angelo Ricarte and Michael Tremmel of Yale and Thomas Quinn of the University of Washington—used sophisticated sets of simulations to make the discovery. Called Romulus, the cosmological simulation follows the evolution of different regions of the universe from just after the Big Bang until the present day and includes thousands of simulated galaxies that reside in a wide variety of cosmic environments.

The Romulus simulations offer the highest-resolution snapshot of black hole growth, providing a fully emergent and sharper view of how black holes grow within a wide range of host galaxies, from the most massive galaxies located in the center of galaxy clusters—very dense regions like crowded city centers—to much more common dwarf galaxies that inhabit the sparser suburbs.

"At a time when the drivers of black hole growth are unclear, these simulations offer a simple picture. They simply grow along with the stars independent of the galaxy's mass, the larger environment, or the cosmic epoch," said Ricarte, a former graduate student of Natarajan's who is now a postdoctoral fellow at Harvard.

One of the more intriguing findings of the study, Ricarte noted, has to do with the way the largest in the universe interact with their host over time. The researchers found that SMBHs and their hosts grow in tandem, and that the relationship is "self-correcting," independent of the kind of environment they inhabit.

"If the SMBH starts to grow too rapidly and gets too big for its galactic home, physical processes ensure that its growth slows down relative to the galaxy," Tremmel explained. "On the other hand, if the SMBH's mass is too small for its galaxy, the SMBH's growth rate increases relative to the size of the galaxy to compensate."


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More information: Angelo Ricarte et al. Tracing black hole and galaxy co-evolution in the Romulus simulations, Monthly Notices of the Royal Astronomical Society (2019). DOI: 10.1093/mnras/stz2161
Provided by Yale University
Citation: Growing old together: A sharper look at black holes and their host galaxies (2019, September 30) retrieved 15 October 2019 from https://phys.org/news/2019-09-sharper-black-holes-host-galaxies.html
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Sep 30, 2019
I suggested such a study confirming the close 'special relationship' long before it was widely acknowledged, or even suspected. (Early 2011, and suffered lot's of ridicule thereafter. How did I know?)

https://phys.org/...ter.html

"I hope to hear the results of a survey correlating galaxy size, age, and structure to it's black hole mass and activity. Can accretion easily explain this core star variability over such short time scales?"

And from today's news:

"The researchers found that SMBHs and their hosts grow in tandem, and that the relationship is "self-correcting," independent of the kind of environment they inhabit."

That is due to the black hole being the actual source of most of the galactic mass! It is formed therein and ejected periodically, as LaViolette has predicted.

Black holes are comologist's porn. They can't leave it alone. Black holes are actually superdense stars, whose extreme surface gravity cause red-shift to near IR.

Sep 30, 2019
More related:
Chicken or Egg? "It looks like the black holes came first. The evidence is piling up,"
https://phys.org/...wth.html

Black holes lead growth: "However, a new study of Chandra data has revealed two nearby galaxies with supermassive black holes that are growing faster than the galaxies themselves."
https://phys.org/...ync.html


Sep 30, 2019
Black holes grow faster than their host: "Black holes have been growing much faster than we thought" "We now know that each ten-fold increase of a galaxy's stellar mass is associated with a much larger 100-fold increase in its black hole mass"
AND
"The researchers have also found the opposite behaviour to exist among the tightly packed clusters of stars that are observed at the centres of smaller galaxies and in disk galaxies like our Milky Way." "In the lower mass galaxies the star clusters, which can contain up to millions of stars, really dominate over the black holes.

Previously it was thought that the star clusters contained a constant 0.2 per cent of the galaxy mass."
https://phys.org/...ter.html

So this supports LaViolette's model that as BH's grow larger, they grow even faster, being increasingly active therein. They produce not only new matter entering our observable universe, but new 'genic' energy from photon blue-shifting.

Sep 30, 2019
And for those screaming inside, 'accretion, accretion', think again:

"In principle, super massive black holes suck in everything," Wang says, "but we found this is not correct." "..they unexpectedly found that most SMBH accrete matter at very low levels."

"..the SMBH has difficulty in accreting such gases. Second, the gases are too hot for the black hole to swallow. Instead it rejects about 99 percent of this super hot material, only letting a small amount in."

https://phys.org/...ume.html

(Intellectual egomaniacs and NSA trolls will mark me down, as logic is uncomfortable. You know who you are!)

Sep 30, 2019
LaViolette is insane. Have I mentioned that before? Lol. This place is full of cranks!

Sep 30, 2019
Only galactic faerie tales include stories of black holes.

Sep 30, 2019
Only galactic faerie tales include stories of black holes.


So you keep saying, dumbo. The fact that they are observed seems to have passed you by. For the one thousandth time, explain the masses as derived by stellar orbits. Explain the masses as shown by gravitational redshift. Explain the event horizon image. Fact is, you have no science. Only a religious belief that idiots like Thornhill aren't lying to you. They are. Sucker.

Sep 30, 2019
Looks pretty much like the whole Electric Universe thing is the fairy tale with sparkly electric unicorns. Observation trumps theory every time.

Oct 01, 2019
Only galactic faerie tales include stories of black holes.

Only monkey antigoracles make belief world contains you as his sockpuppet and stories about you driving into trees. ;) as you go..DOH ! LOL

Oct 01, 2019
Galaxys born inside to outside.

First born supermassive concentrations with out pulling force and with out curving space.

Every one with own 3 D Big Bang.

Then two expanding supermassive concentrations collide together and then born one new expanding galaxy.


Oct 01, 2019
Expanding stars pushing away From expanding galaxy centre supermassive concentration which expanding and emit expanding dark matter which have nature of expanding stars and nature of expanding visible matter.


Oct 01, 2019
I suggested such a study confirming the close 'special relationship' long before it was widely acknowledged, or even suspected. (Early 2011, and suffered lot's of ridicule thereafter. How did I know?)


False. The M - sigma relation was discovered in 2000, even years before that there were papers looking into such relationships. As you can see the Ferrarese & Merritt (2000) paper accumulated over 1500 citations before 2011. Not only was co-evolution widely acknowledged, it was a hot topic.

https://ui.adsabs...abstract

You did not predict anything, the only thing you have demonstrated is the depth of your ignorance.

Oct 01, 2019
Well, not being a cosmologist, I may be ignorant of all the published papers, but LaViolette predicted this basic relationship back in the mid-eighties. Was it a hot topic then, hot shot?

Oct 01, 2019
LaViolette predicted this basic relationship back in the mid-eighties.


Notice that I provided the citation to back up my claim, including an open access version of the paper. Why don't you find the exact quote where he predicts a relation between black hole mass and the velocity dispersion of the bulge? And don't just wave at his book, it's your assertion.

Oct 02, 2019
Expanding space is naked empire.

Curving space also naked empire.

Oct 02, 2019
so mrp, you've begun a career as a tailor's apprentice?

took you long enough for realizing your limitations

now if only the other loonneytoons
were competent to realize
they will never rise
beyond their present janitorial careers

Oct 02, 2019
Expanding space is naked empire.

Curving space also naked empire.


Ahaaaa! As Alan Partridge would say! Guess what, Mr Pushing Force? You are a complete f***wit. Deal with that, and then get back to us. Wazzock.

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