Astronomers find evidence for unusual class of black holes

Thought I'd share this, an international team of scientists using the VLT (very large telescope) in Chile say they may have found further evidence for the existence of an unusual type of black hole. note the may... they have been studying a black hole called HLX-1 it's located some 300 million light years away from Earth.

If confirmed, HLX-1 would be classified as an intermediate-type black hole - something astrophysicists suspected to exist, but for which there have been only tentative detections in the past.

I may sound a bit dumb but I personally would have thought black holes would start small after a large star went supernover and grow larger as time and gravity took hold, thus dragging in planets to form a galaxy, but apparently scientists (according to this article) are still trying to figure out how our Galaxy formed...

Understanding how super-massive black holes form and grow is thus crucial to our comprehension of the formation and evolution of galaxies, which in turn goes part of the way to answering one of the really big questions: how did our own galaxy form and evolve?" said astronomer Sean Farrell, also of the University of Leicester.

Source

It's strange that this HLX1 sits on the edge of a galaxy (ESO243-49) but yet has no swirling mass of stars surrounding it. It's hard to imagine how it was created without heaps of matter being drawn into it's influence.
Maybe it was once a small galaxy (or a very large solar system) that has swallowed all of it's stars (or planets) and all that remains is the black hole, which has drawn itself toward another galaxy that it will now tear through on it's way to the centre.

reply to post by primomofo



Hi primomofo, I had a look into HLX1 from the original source (the astrophysical journal) and it would appear HLX-1 is inside ESO 243-49 not on the edge, what's amazing is the luminosity of this black hole:

the maximum observed 0.2-10 keV luminosity is 1.2 × 1042 erg s–1. This luminosity is ~400 times above the Eddington limit for a 20 M black hole.

So in X-ray this thing shines very very bright! In fact so bright it's the brightest ultra-luminous X-ray source known! Whether it was originally born in ESO 243-49 or has like you say drawn itself towards ESO 243-49 I couldn't tell you, but it's claimed it's a quiescent neutron star X-ray binary, interesting find on behalf of the astronomers involved!

astrophysical journal