Tidal disruption events (TDEs) occur when a star, passing too close to a massive black hole, is ripped apart by tidal forces. A less dramatic event occurs if the star orbits just outside the tidal radius, resulting in a mild stripping of mass. Thus, if a star orbits a central black hole on one of these bound eccentric orbits, weaker outbursts will occur recurring every orbital period. Thanks to five Swift observations, we observed a recent flare from the close by (92 Mpc) galaxy IC 3599, where a possible TDE was already observed in December 1990 during the Rosat All-Sky Survey. By light curve modeling and spectral fitting, we account for all these events as the non-disruptive tidal stripping of a single star into a 9.5 yr highly eccentric bound orbit. This is the first example of periodic partial tidal disruptions, possibly spoon-feeding the central black hole.
@article{arxiv.1502.07835,
title = {"Spoon-feeding" an AGN},
author = {Deborah Mainetti and Sergio Campana and Monica Colpi and Giuseppe Lodato and Paolo D'Avanzo and Phil Evans and Alberto Moretti},
journal= {arXiv preprint arXiv:1502.07835},
year = {2015}
}
Comments
7 pages, 3 figures, to appear in "Swift:10 years of discovery", Proceedings of Science