# A likely decade-long sustained tidal disruption event

## TL;DR

This paper reports the discovery of an exceptionally long-lasting super-Eddington tidal disruption event in a dwarf galaxy, providing new insights into black hole accretion processes over a decade.

## Contribution

It presents the first observation of a super-long (>11 years) tidal disruption event with sustained super-Eddington accretion, expanding understanding of black hole feeding mechanisms.

## Key findings

- Persistent high X-ray luminosity near Eddington limit over a decade
- Spectral softening indicating state transition or transient absorber
- Evidence of super-Eddington accretion in a dwarf galaxy

## Abstract

Multiwavelength flares from tidal disruption and accretion of stars can be used to find and study otherwise dormant massive black holes in galactic nuclei. Previous well-monitored candidate flares are short-lived, with most emission confined to within ~1 year. Here we report the discovery of a well observed super-long (>11 years) luminous soft X-ray flare from the nuclear region of a dwarf starburst galaxy. After an apparently fast rise within ~4 months a decade ago, the X-ray luminosity, though showing a weak trend of decay, has been persistently high at around the Eddington limit (when the radiation pressure balances the gravitational force). The X-ray spectra are generally soft (steeply declining towards higher energies) and can be described with Comptonized emission from an optically thick low-temperature corona, a super-Eddington accretion signature often observed in accreting stellar-mass black holes. Dramatic spectral softening was also caught in one recent observation, implying either a temporary transition from the super-Eddington accretion state to the standard thermal state or the presence of a transient highly blueshifted (~0.36c) warm absorber. All these properties in concert suggest a tidal disruption event of an unusually long super-Eddington accretion phase that has never been observed before.