Unveiling New Quiescent Black Holes with IPHAS

Abstract

Soft X-ray transients (SXTs) provide the best evidence for the existence of stellar-mass black holes (BHs) with almost 20 conrmed systems based on dynamical studies. However, there is an estimated population of a few thousand dormant BH binaries, which slowly reveal themselves through secular X-ray outbursts. Therefore, new strategies aimed at unveiling this dormant population are clearly needed. We propose to use the IPHAS catalogue, together with several diagnostic diagrams, as a shortcut to unveil the brightest members of the Galactic population of BH binaries. Here we present some of the diagrams we are using to distinguish between SXTs and other types of object found by the IPHAS survey.