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arXiv · 1502.07835

"Spoon-feeding" an AGN

Deborah Mainetti·Sergio Campana·Monica Colpi·Giuseppe Lodato·Paolo D'Avanzo·Phil Evans·Alberto Moretti
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Abstract

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.

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Deborah Mainetti, Sergio Campana, Monica Colpi, Giuseppe Lodato, Paolo D'Avanzo, Phil Evans, Alberto Moretti. 2015-02-27. "Spoon-feeding" an AGN. https://arxiv.org/abs/1502.07835

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