The missing link between ultra-luminous X-ray sources and metallicity
Abstract
The nature of ultra-luminous X-ray sources is still debated. Recent studies show that metal-poor massive stars can collapse into massive stellar black holes (MSBHs), that is black holes with mass > 25 solar masses. Such MSBHs are sufficiently massive to explain most ULXs without requiring substantial violations of the Eddington limit. The recent finding of an anti-correlation between metallicity of the environment and number of ULXs per galaxy supports this hypothesis. I discuss the results of recent N-body simulations, including metallicity dependent stellar evolution, that show which are the main pathways to produce X-ray binaries powered by MSBHs.
- Publication:
-
Half a Century of X-ray Astronomy
- Pub Date:
- September 2012
- Bibcode:
- 2012hcxa.confE..80M