Tidal disruption of a super-Jupiter by a massive black hole

TL;DR

This paper reports the observation of a tidal disruption event in NGC 4845, where a super-Jupiter was torn apart by a massive black hole, revealing a forming corona and providing insights into such extreme astrophysical phenomena.

Contribution

It presents the first observation of a corona forming around a black hole during a tidal disruption event involving a super-Jupiter.

Findings

Black hole mass estimated at ~3x10^5 solar masses.

Disruption of about 10% of a 14-30 Jupiter mass object.

First detection of a corona in a tidal disruption event.

Abstract

Aims: A strong, hard X-ray flare was discovered (IGR J12580+0134) by INTEGRAL in 2011, and is associated to NGC 4845, a Seyfert 2 galaxy never detected at high-energy previously. To understand what happened we observed this event in the X-ray band on several occasions. Methods: Follow-up observations with XMM-Newton, Swift, and MAXI are presented together with the INTEGRAL data. Long and short term variability are analysed and the event wide band spectral shape modelled. Results: The spectrum of the source can be described with an absorbed (N_H ~ 7x10^22 cm^{-2}) power law (\Gamma \simeq 2.2), characteristic of an accreting source, plus a soft X-ray excess, likely to be of diffuse nature. The hard X-ray flux increased to maximum in a few weeks and decreased over a year, with the evolution expected for a tidal disruption event. The fast variations observed near the flare maximum allowed us to estimate the mass of the central black hole in NGC 4845 as ~ 3x10^5 Msun. The observed flare corresponds to the disruption of about 10% of an object with a mass of 14-30 Jupiter. The hard X-ray emission should come from a corona forming around the accretion flow close to the black hole. This is the first tidal event where such a corona has been observed.