Speaker
Description
We present our simulations and predictions for eROSITA's potential contributions to the study of X-ray emission from normal (i.e., not AGN) galaxies. We start from multiwavelength catalogues, including ultraviolet, optical, and infrared data, to measure star formation rates and stellar masses for 60,212 galaxies constrained to distances of 50-200 Mpc. This distance range was chosen to focus on the relatively unexplored volume outside the more local Universe, which will be largely spatially unresolved and will represent a statistically significant new sample of X-ray detected galaxies. Using updated X-ray scaling relations, we predict the X-ray emission from XRBs and diffuse hot gas. Additionally, we include potential contributions from hidden AGN. In this presentation, I will discuss the galaxies that eROSITA will likely detect, based on the expected 4-year sensitivity limits and survey capabilities of this telescope and summarize the distribution of morphological types and the relative contribution of X-ray emission from HMXBs, LMXBs, and hot gas. Based on our conservative approach, we estimate that the eROSITA 4-year survey will detect ~16,000 galaxies (3 sigma significance) at 50-200 Mpc over the full sky, which is ~100X more normal galaxies than detected in any X-ray survey to date. The significantly increased sample will enable statistical studies to explore the underlying physics of the X-ray emission, i.e, the evolution of X-ray binaries and hot ISM in galaxies.
