Evidence for a Stellar Disruption by an Intermediate-mass Black Hole in an Extragalactic Globular Cluster

Irwin, J.A.; Brink, T.G.; Bregman, J.N.; Roberts, T.P.

Abstract

We report [O III] λ5007 and [N II] λ6583 emission from a globular cluster harboring the ultraluminous X-ray source CXOJ033831.8 – 352604 in the Fornax elliptical galaxy NGC 1399. No accompanying Balmer emission lines are present in the spectrum. One possibility is that the forbidden lines emanate from X-ray-illuminated debris of a star that has been tidally disrupted by an intermediate-mass black hole, with this debris also feeding the black hole leading to the observed X-ray emission. The line strengths indicate that the minimum size of the emitting region is ~1015 cm, and if the 70 km s–1 half-widths of the emission lines represent rotation around the black hole, a minimum black hole mass of 1000 M ☉ is implied. The non-detection of Hα and Hβ emission lines suggests a white dwarf star was disrupted, although the presence of strong nitrogen emission is somewhat of a mystery.

Citation

Irwin, J., Brink, T., Bregman, J., & Roberts, T. (2010). Evidence for a Stellar Disruption by an Intermediate-mass Black Hole in an Extragalactic Globular Cluster. Astrophysical Journal Letters, 712(1), L1-L4. https://doi.org/10.1088/2041-8205/712/1/l1

• Journal Article Type: Article
• Publication Date: Mar 20, 2010
• Deposit Date: Jan 30, 2012
• Publicly Available Date: Feb 19, 2014
• Journal: Astrophysical Journal Letters
• Print ISSN: 2041-8205
• Electronic ISSN: 2041-8213
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 712
• Issue: 1
• Pages: L1-L4
• DOI: https://doi.org/10.1088/2041-8205/712/1/l1
• Keywords: Galaxies, Individual (NGC 1399), Star clusters, Globular clusters, X-rays, Binaries.
• Public URL: https://durham-repository.worktribe.com/output/1520995