Spatially Resolved Spectroscopy of the Globular Cluster RZ2109 and the Nature of its Black Hole
Abstract
We present optical HST/STIS spectroscopy of RZ2109, a globular cluster in the elliptical galaxy NGC4472. This cluster is notable for hosting an ultraluminous X-ray source and is known to have associated strong and broad [OIII] emission. Our observations of this cluster spatially resolve its [OIII] emission and are used to demonstrate that the nebula is similar in scale to the cluster itself, with a half light radius of at least a few parsecs. The properties of this nebula provide important constraints on the source of the emission observed from this cluster. We show that the large spatial scale of the nebula is inconsistent with models that invoke an intermediate mass black hole origin. It is also inconsistent with other models that propose the ionization of ejecta from a nova in the cluster. We show that the nebular emission could be produced via the photoionization of a strong wind driven from a stellar mass black hole that is accreting at roughly its Eddington rate.
- Publication:
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AAS/High Energy Astrophysics Division #13
- Pub Date:
- April 2013
- Bibcode:
- 2013HEAD...1311303P