Surrey: Star System Hosts Hundreds of Black Holes

[bystander]

New Research Reveals Hundreds of Undiscovered Black Holes
University of Surrey | 2016 Sep 08

[img3="Hubble Image of Globular Cluster NGC 6101
Credit: NASA HST/wiki commons"]https://upload.wikimedia.org/wikipedia/ ... C_6101.jpg[/img3][hr][/hr]

New research by the University of Surrey published today in the journal Monthly Notices of the Royal Astronomical Society has shone light on a globular cluster of stars that could host several hundred black holes, a phenomenon that until recently was thought impossible.

Globular clusters are spherical collections of stars which orbit around a galactic center such as our Milky Way galaxy. Using advanced computer simulations, the team at the University of Surrey were able to see the un-see-able by mapping a globular cluster known as NGC 6101, from which the existence of black holes within the system was deduced. These black holes are a few times larger than the Sun, and form in the gravitational collapse of massive stars at the end of their lives. It was previously thought that these black holes would almost all be expelled from their parent cluster due to the effects of supernova explosion, during the death of a star. ...

It is only as recently as 2013 that astrophysicists found individual black holes in globular clusters via rare phenomena in which a companion star donates material to the black hole. This work, which was supported by the European Research Council (ERC), has shown that in NGC 6101 there could be several hundred black holes, overturning old theories as to how black holes form. ...

A Stellar-Mass Black Hole Population in the Globular Cluster NGC 6101? - Miklos Peuten et al

• Monthly Notices of the RAS 462(3):2333 (2016 Nov 01) DOI: 10.1093/mnras/stw1726
  arXiv.org > astro-ph > arXiv:1609.01720 > 06 Sep 2016

[Ann]

Fascinating indeed. Of course, we need confirmation that the black holes are actually there.

Nevertheless, it makes sense that there should be black holes in globulars. When the globulars were young, they must have been simply incredibly dense and crammed full of massive stars which soon exploded as supernovas. That sounds like fertile ground for making very many stellar-mass black holes to me.

Ann