Περίληψη :
The X-ray emission of star-forming galaxies can arise from accreting compact objects in X-ray binaries, hot diffuse gas, or an active galactic nucleus (AGN). We investigate whether differences in stellar populations and recent star-formation histories can help explain the enhanced X-ray emission of nearby galaxies, while assessing a possible contribution from nuclear activity, using measurements from the cumulative eROSITA eRASS:3 dataset. We combine ultraviolet photometry from GALEX catalogues with optical-to-mid-infrared data from HECATE v2 and fit the spectral energy distributions using CIGALE. Models with and without an active galactic nucleus (AGN) component are examined, and galaxies detected in X-rays are compared with galaxies having X-ray upper limits within bins of star formation rate and stellar mass. The inferred stellar population properties suggest contributions from both high-mass and low-mass X-ray binaries, although their individual contributions are not directly measured. Galaxies detected in X-rays generally have larger inferred burst mass fractions than the comparison galaxies. A tentative preference for older recent bursts is also found, but the coarse sampling of burst age prevents a firm determination of the relevant timescale. The AGN-inclusive fits do not establish a dominant AGN contribution across the sample, although a few candidate sources remain uncertain. These results indicate that star-formation history is relevant to interpreting enhanced X-ray emission, while finer and wider parameter grids are required to establish the burst-age dependence and assess the robustness of the inferred stellar populations.
