Evidence of a Tidal-disruption Event in GSN 069 from the Abnormal Carbon and Nitrogen Abundance Ratio

Zhenfeng Sheng, Tinggui Wang, Gary Ferland, Xinwen Shu, Chenwei Yang, Ning Jiang, Yang Chen

Research output: Contribution to journalArticlepeer-review

22 Scopus citations

Abstract

GSN 069 is an ultra-soft X-ray active galactic nucleus that previously exhibited a huge X-ray outburst and a subsequent long-term decay. It has recently presented X-ray quasi-periodic eruptions (QPEs). We report the detection of strong nitrogen lines but weak or undetectable carbon lines in its far-ultraviolet spectrum. With a detailed photoionization model, we use the C iv/N iv] ratio and other ratios between nitrogen lines to constrain the [C/N] abundance of GSN 069 to be from -3.33 to -1.91. We argue that a partially disrupted red giant star can naturally explain the abnormal C/N abundance in the UV spectrum, while the surviving core orbiting the black hole might produce the QPEs.

Original languageEnglish
Article numberL25
JournalAstrophysical Journal Letters
Volume920
Issue number1
DOIs
StatePublished - Oct 10 2021

Bibliographical note

Publisher Copyright:
© 2021. The American Astronomical Society. All rights reserved..

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint

Dive into the research topics of 'Evidence of a Tidal-disruption Event in GSN 069 from the Abnormal Carbon and Nitrogen Abundance Ratio'. Together they form a unique fingerprint.

Cite this