Vol. 670
4. Extragalactic astronomy

Repeating tidal disruptions in GSN 069: Long-term evolution and constraints on quasi periodic eruptions' models

by G. Miniutti, M. Giustini, R. Arcodia, et al. 2023, A&A, 670, A93

Quasi-periodic eruptions (QPEs) are recurrent, large-amplitude X-ray outbursts that have recently been discovered in the nuclei of distant galaxies. In this paper, Miniutti et al. report a thorough analysis of the first QPE source, GSN 069, over 12 years. GSN 069 was first observed in 2010, showing no QPE. In the following years, the X-ray flux steadily decreased. Eight years after the first observations, QPEs were readily observed. They lasted a little over a year and disappeared as the source flux increased again. The 12 year-long evolution of the GSN 069 emission (QPE excised) is consistent with two different tidal disruption events, ∼, which are nine years apart. This study strengthens the connection between the QPE and tidal disruption of stars.