Monthly quasi-periodic eruptions from repeated stellar disruption by a massive black hole

TL;DR

This paper reports the discovery of a new X-ray transient with quasi-periodic outbursts, potentially linking two classes of stellar disruption events caused by black holes, highlighting the importance of rapid X-ray transient detection.

Contribution

It introduces a newly observed X-ray transient that bridges two known classes of stellar disruption phenomena, expanding understanding of black hole interactions.

Findings

Discovered an X-ray transient with weeks-long quasi-periodic outbursts.

Proposed that this system connects two previously separate classes of stellar disruption events.

Demonstrated the effectiveness of rapid, low-latency X-ray transient detection methods.

Abstract

In recent years, searches of archival X-ray data have revealed galaxies exhibiting nuclear quasi-periodic eruptions with periods of several hours. These are reminiscent of the tidal disruption of a star by a supermassive black hole, and the repeated, partial stripping of a white dwarf in an eccentric orbit around a ~10^5 solar mass black hole provides an attractive model. A separate class of periodic nuclear transients, with significantly longer timescales, have recently been discovered optically, and may arise from the partial stripping of a main-sequence star by a ~10^7 solar mass black hole. No clear connection between these classes has been made. We present the discovery of an X-ray nuclear transient which shows quasi-periodic outbursts with a period of weeks. We discuss possible origins for the emission, and propose that this system bridges the two existing classes outlined above. This discovery was made possible by the rapid identification, dissemination and follow up of an X-ray transient found by the new live \swift-XRT transient detector, demonstrating the importance of low-latency, sensitive searches for X-ray transients.