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Center of the Milky Way Has Thousands of Black Holes, Study Shows (npr.org)
New submitter xonen shares a report from NPR: For decades, scientists have thought that black holes should sink to the center of galaxies and accumulate there. But scientists had no proof that these exotic objects had actually gathered together in the center of the Milky Way. Isolated black holes are almost impossible to detect, but black holes that have a companion -- an orbiting star -- interact with that star in ways that allow the pair to be spotted by telltale X-ray emissions. The team searched for those signals in a region stretching about three light-years out from our galaxy's central supermassive black hole. What they found there: a dozen black holes paired up with stars. Finding so many in such a small region is significant, because until now scientists have found evidence of only about five dozen black holes throughout the entire galaxy. What they've found should help theorists make better predictions about how many cosmic smashups might occur and generate detectable gravitational waves. The study has been published in the journal Nature.
That sucks.
This is a very interesting result since it may have implications for Dark Matter. There is a gamma ray 'haze' around the central core of the galaxy that has caused some interest because without what used to be thought of as an unfeasibly large number of pulsars it would be impossible to produce from known astrophysical and so the thought was that it could be due to Dark Matter annihilations. However, if there is a far higher population of BHs than originally thought presumably this also means there should be a lot more pulsars and, if so, then this haze could be just from all these pulsars.
You know, I told my precious star to stop hanging out with those no good singularity but did she listen? NOOOooo. She said, "he's just in my orbit" but then was consumed by him talking about "singularity this" and "singularity that" all the time. Before you know it you walk in on her are kissing that beatnik's event horizon, she goes critical and now is just like that jerk! That's when she starts merging with him in public for everyone to see! I know she has always had a warped perspective of time and space but this is on a whole new level!
Parents, you've been warned! ;)
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This isn't really true. Black holes do not suck things in. The natural behavior of an object interacting with a black hole is to form a stable orbit around it, just as it would around a star. To actually fall in, even on purpose, would take an enormous delta-v.
The only way anything falls in is:
1. If it's on a direct collision course
2. If it enters an accretion disc, that has some sort of viscosity
3. If it gets close enough that the gravity waves radiated from the pair are significant
I was having troubles seeing how this could work. Unless you are very close indeed, a 5 solar mass black hole interacts with other stars in exactly the same way as a 5 solar mass star, as the only force in action is gravity. So how can these stellar mass black holes gather near the galactic core?
The first sentence of the paper is: "The existence of a ‘density cusp’—a localized increase in number—of stellar-mass black holes near a supermassive black hole is a fundamental prediction of galactic stellar dynamics".
I looked up the reference for this (Bahcall and Wolf, http://adsabs.harvard.edu/doi/...). It is late at night and decades since I studied stuff like this, so mostly I'm going on that paper's abstract plus a bit of background knowledge.
The important assumption of Bahcall and Wolf is that the stars are much less massive than the small black holes (SBH), which are much less massive than the galactic black hole (GBH). (My error was in not considering this.) Now when you have a mixture of stars and SBHs near the GBH, they are zipping around and sometimes have close encounters where they gravitationally interact. These interactions on average will shift kinetic energy from the higher energy object to the lower energy object. Due to the mass difference, this means in a SBH/star interaction, the SBH will (more often than not) transfer energy to the star, so it will slow and fall deeper into the gravitational well of the GBH.
A good analogy is a gas with heavy and light molecules. The heavy molecules will move more slowly and at the bottom of the container the gas will be richer in heavy molecules compared to at the top of the container.
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The reason "science" is losing it's credibility is really stupid people, who don't understand "science," and who prefer to be intentionally stupid and not learn, keep making posts like yours. Or rather, it's why "science" is losing credibility with really stupid people.
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Why is this +5? A BH most certainly does "suck in" a lot of matter. And orbits aren't default stable configurations.
Object which enter the system with the black hole are on a hyperbolic orbit and will leave with the same hyperbolic orbit unless they interact in such a way as to change their orbit.