Galactic X-ray Transients in eROSITA

We have used the ROSAT, eROSITA and Gaia source catalogs to find Galactic X-ray transients having timescales <30 years. We report the properties of 738 transients found in our search, majority of which are active stars or interacting binaries.

We have also found ~40 compact object systems among which are at least 8 newly-identified white-dwarf systems, 3 known X-ray binaries, and one known pulsar. We use eROSITA (soft X-ray) spectra of the Galactic transients to show that two distinct types of flaring systems are prevalent: one having peak around 1keV, well fit by thermal models, and another having peak below 0.2keV and requiring a power-law component. Our study also reveals that single star or interacting binary systems (X-ray transients) involving giant stars exhibit significantly higher X-ray luminosities than systems involving only main-sequence stars or young stellar objects.