Evidence of a Tidal-disruption Event in GSN 069 from the Abnormal Carbon and Nitrogen Abundance Ratio
- 1 October 2021
- journal article
- research article
- Published by American Astronomical Society in The Astrophysical Journal Letters
- Vol. 920 (1), L25
- https://doi.org/10.3847/2041-8213/ac2251
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.Keywords
This publication has 31 references indexed in Scilit:
- The chemical composition of the SunAstrophysics and Space Science, 2010
- A Sample of Quasars with Strong Nitrogen Emission Lines from the Sloan Digital Sky SurveyThe Astrophysical Journal, 2008
- Tidal Disruption of a Star by a Black Hole: Observational SignatureThe Astrophysical Journal, 2004
- Chemical Abundances in Broad Emission Line Regions: The “Nitrogen‐loud” Quasi‐Stellar Object Q0353−383The Astrophysical Journal, 2003
- Metallicities and Abundance Ratios from Quasar Broad Emission LinesThe Astrophysical Journal, 2002
- Elemental Abundances in Quasistellar Objects: Star Formation and Galactic Nuclear Evolution at High RedshiftsAnnual Review of Astronomy and Astrophysics, 1999
- Maps of Dust Infrared Emission for Use in Estimation of Reddening and Cosmic Microwave Background Radiation ForegroundsThe Astrophysical Journal, 1998
- An Unstable Central Disk in the Superluminal Black Hole X-Ray Binary GRS 1915+105The Astrophysical Journal, 1997
- The Chemical Evolution of QSOs and the Implications for Cosmology and Galaxy FormationThe Astrophysical Journal, 1993
- Gas clouds from tidally disrupted stars in active galactic nucleiThe Astrophysical Journal, 1992