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Title: Composition of an emission line system in black hole host globular cluster RZ2109

We present an analysis of optical spectra from the globular cluster RZ2109 in NGC 4472, which hosts the first unambiguous globular cluster black hole. We use these spectra to determine the elemental composition of the emission line system associated with this source, and to constrain the age and metallicity of the host globular cluster. For the emission line system of RZ2109, our analysis indicates the [O III] λ5007 equivalent width is 33.82 ± 0.39 Å and the Hβ equivalent width is 0.32 ± 0.32 Å, producing a formal [O III] λ5007/Hβ emission line ratio of 106 for a 3200 km s{sup –1} measurement aperture covering the full velocity width of the [O III] λ5007 line. Within a narrower 600 km s{sup –1} aperture covering the highest luminosity velocity structure in the line complex, we find [O III] λ5007/Hβ = 62. The measured [O III] λ5007/Hβ ratios are significantly higher than can be produced in radiative models of the emission line region with solar composition, and the confidence interval limits exclude all but models which have gas masses much larger than those for a single star. Therefore, we conclude that the region from which the [O III] λ5007 emission originates ismore » hydrogen-depleted relative to solar composition gas. This finding is consistent with emission from an accretion-powered outflow driven by a hydrogen-depleted donor star, such as a white dwarf, being accreted onto a black hole.« less
Authors:
;  [1] ;  [2] ;  [3] ; ;  [4]
  1. Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)
  2. Department of Physics, Texas Tech University, Lubbock, TX 79409 (United States)
  3. Eureka Scientific, 2452 Delmer Street Suite 100, Oakland, CA 94602-3017 (United States)
  4. Department of Astronomy, Indiana University, Bloomington, IN 47405 (United States)
Publication Date:
OSTI Identifier:
22357073
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 785; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APERTURES; BLACK HOLES; EMISSION; HYDROGEN; LUMINOSITY; MASS; METALLICITY; SPECTRA; STAR CLUSTERS; VELOCITY; WHITE DWARF STARS; X RADIATION; X-RAY GALAXIES