If you thought black holes only came in S or XXXL, guess again, maybe: Elusive mid-mass void spotted eating star
- Reference: 1585810869
- News link: https://www.theregister.co.uk/2020/04/02/medium_black_hole/
- Source link:
Observed black holes typically come in two sizes: small ones ten to 100 times the mass of the Sun, and gigantic supermassive ones that are millions to thousands of billions the mass of the Sun. There seems to be no in-between; although medium-sized ones can theoretically exist, scientists haven’t observed any to date with high confidence.
Now, a team of boffins working across the US, France, and the Netherlands believe they have found a promising candidate for one of these elusive in-between black holes, measuring about 50,000 solar masses. Snappily code-named 3XMM J215022.4−055108, the eggheads discovered the intriguing object while combing through signals gathered by NASA’s Chandra X-ray Observatory and the European Space Agency’s X-ray Multi-Mirror Mission (XMM-Newton) spacecraft.
As the names of the probes suggest, the academics were drawn to 3XMM J215022.4−055108 after spotting a burst of radiation that appeared to be the result of a star wandering too close to a black hole.
“The most promising explanation for the source is that it is an intermediate mass black hole in an off-center star cluster with the X-ray and optical outburst due to a tidal disruption event (TDE), in which a star having a close encounter with the black hole was tidally disrupted and subsequently accreted, producing the multiwavelength flare,” according to the team's write-up, [1]published in The Astrophysical Journal Letters this week. Here’s the free [2]pre-print version .
Observations made using NASA’s Hubble Space Telescope revealed the burst was emanating from the edge of a lenticular galaxy. The researchers have ruled out the possibility that their discovery is just a cooling neutron star.
The missing link
Supermassive black holes are found closer to the center of a galaxy, unlike 3XMM J215022.4−055108. Based on the X-ray spectra, the scientists calculated that the object’s mass is more than 50,000 times that of the Sun making it more substantial than stellar-size black holes but not quite as significant as the stupidly massive ones.
I've seen things you people wouldn't believe. Black hole quasar tsunamis moving at 46 million miles per hour [3]READ MORE
Dacheng Lin, first author of the study and a research scientist at the University of New Hampshire, United States, told The Register that intermediate-mass black holes (IMBHs) have been difficult to find because they're less active than supermassive ones.
“Intermediate mass black holes might not be rare," he said. "In fact, our identification of this event which is expected to rarely occur means that there should be many IMBHs in our local universe. They are hardly seen just because they tend to sit in the environment with few materials to accrete.”
In short, the scientists appear to have caught their target in the midst of feasting on nearby star that came too close and detected the large emission of electromagnetic energy from the accretion process.
“Studying the origin and evolution of the intermediate mass black holes will finally give an answer as to how the supermassive black holes that we find in the centres of massive galaxies came to exist,” [4]said Natalie Webb, co-author of the study and a astrophysicist at the University of Toulouse, France. ®
[1] https://iopscience.iop.org/article/10.3847/2041-8213/ab745b
[2] https://arxiv.org/abs/2002.04618
[3] https://www.theregister.co.uk/2020/03/21/quasar_tsunamis/
[4] https://www.spacetelescope.org/news/heic2005/
Re: Only in Astronomy
The issue is in the non-existing upper limit, for "50000 sun masses" is indeed rather big. The biggest "hypergiant" size stars we know about are AFAIK around 20-30 times the mass of our sun, so one can imagine the number of stars of all sizes this black hole had to gobble to get to that size!
“Intermediate mass black holes might not be rare,"
So we now know that there are indeed intermediate-mass black holes, which we did not know before. Since we didn't know that, we could not factor their mass in our calculations for the amount of normal matter that exists in the Universe, which means our ratio of dark matter to normal matter is wrong.
Of course, we still don't know how much mass is harbored inside those things, and evaluating that is not going to be easy.
Add to that the fact that brown dwarfs are also an unknown quantity and it seems to me that there is significantly more normal matter than we initially thought. Probably not enough to do away with dark matter, but likely more than the 15% it is apparently currently pegged at.
Re: “Intermediate mass black holes might not be rare,"
Not very much, space you see is really big...
They are seemingly rare, and whilst very massive, are only 5 orders of magnitude smaller than their biggest cousins.
The above is true for brown dwarves too, though they may not turn out to be quite as rare.
Overall I'd be very surprised if it made as much as a ppm adjustment, however I'm not a boffin,
he is>>>
Re: “Intermediate mass black holes might not be rare,"
In fact we do know there are not enough relatively small, electromagnetically quiet objects (such as intermediate-mass BHs, brown dwarfs &c) to account for a significant amount of the missing mass, because we can 'see' such things through gravitational microlensing: when they pass in front of more distant objects the light from those objects gets bent and you get, for instance, multiple images of them.
One of the early hypotheses for dark matter was lots of quiet BHs and this got ruled out by the lack of enough observed microlensing.
So although it's nice that we now know there are some, we already knew there were not enough to account for the missing mass, aka dark matter.
Lower and upper limits
1) Lower limit: this comes from extrapolating the observed clumping effect, gravity, up to the point at which the escape velocity matches the constant 'speed of light' at which point light cannot escape and we have an event horizon and a black hole.
2) Upper limit: this is from estimating how much clumping could occur since God 'Bigus Bangus' created the universe and all of space and time, but not the dimension that inflation works in, that dimension is different.
Those two define the assumed limits for black hole sizes.
And at the sub-atomic end, gravity is some clumping effect of (some) matter particles which disappears when matter is converted to energy. And somehow when energy becomes matter, the gravity property returns, and light stops moving, somehow it doesn't escape, but this time nothing to do with gravity, no sir this is an energy to matter conversion that just happens, poof, and there it is.
And if I slap a mass of equations over that, label everything with magic keywords, this is the state of physics today.
Re: Lower and upper limits
Yes of course, it's so simple...
Why didn't I think of that???
Re: Lower and upper limits
Too many shrooms with your full-English this morning?
Only in Astronomy
does 50,000 times the mass of the sun not qualify as super massive. The mind boggles at such numbers.
Well done spotting this intermediate-mass black hole!