XMMSL1J063045.9-603110: a tidal disruption event fallen into the back burner

TL;DR

This paper presents evidence that XMMSL1J063045.9-603110 is a tidal disruption event involving a black hole, characterized by X-ray spectral features and flux decay consistent with theoretical models, suggesting the presence of intermediate-mass black holes in small galaxies or clusters.

Contribution

The study identifies and analyzes a candidate tidal disruption event with detailed X-ray spectral and flux decay analysis, supporting the existence of intermediate-mass black holes in small galaxies or globular clusters.

Findings

X-ray spectrum consistent with a thermal accretion disc

Flux decay follows a t^-5/3 law

Likely associated with a small galaxy or globular cluster

Abstract

Black holes at the centre of quiescent galaxies can be switched on when they accrete gas that is gained from stellar tidal disruptions. A star approaching a black hole on a low angular momentum orbit may be ripped apart by tidal forces, which triggers raining down of a fraction of stellar debris onto the compact object through an accretion disc and powers a bright flare. In this paper we discuss XMMSL1J063045.9-603110 as a candidate object for a tidal disruption event. The source has recently been detected to be bright in the soft X-rays during an XMM-Newton slew and later showed an X-ray flux decay by a factor of about 10 in twenty days. We analyse XMM-Newton and Swift data. XMMSL1J063045.9-603110 shows several features typical of tidal disruption events: the X-ray spectrum shows the characteristics of a spectrum arising from a thermal accretion disc, the flux decay follows a t^-5/3 law, and the flux variation is > 350. Optical observations testify that XMMSL1J063045.9-603110 is probably associated with an extremely small galaxy or even a globular cluster, which suggests that intermediate-mass black holes are located in the cores of (at least) some of them.