Pellizza, Leonardo J.
Argentina Institute for Astronomy and Space Physics (UBA-CONICET)
X-ray binary feedback over the interstellar and intergalactic media
The properties of the first generations of stars formed at the Cosmic Dawn (10^8 − 10^9 yr after the Big Bang) and their influence on the subsequent evolution of galaxies are fundamental research topics in extragalactic astrophysics. Several authors have suggested that X-ray binaries (XRBs) may have contributed significantly to the energy feedback into their environment at that epoch, participating in the regulation of the cosmic star formation and the ionization state of the intergalactic medium [1, 2, 3]. The determination of the properties of XRB populations in the Early Universe is therefore important. This can be done by exploring XRB populations in low-metallicity galaxies at redshift zero, which are assumed to be the local analogs of those prevailing at Cosmic Dawn [4, 5, 6]. To this aim, we investigated the correlations between X-ray luminosity, star formation rate, mass and metallic-
ity of a sample of local galaxies in which XRBs have been detected. We compared them with the general sample of local galaxies [7, 8, 9], finding a bias towards low metallicity in the former. After homogenizing the data we discarded the possibility of the bias being caused by some systematics. We modelled XRB populations using cosmological hydrodynamical numerical simulations of galaxy formation and evolution [8, 9], coupled to our XRB population synthesis model, to determine the origin of this bias. In this poster we show our preliminary results which suggest that the bias may arise in the effect of the metallicity dependence of XRB evolution on the properties of the population, in agreement with previous results.