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arXiv · 1209.6253

Spatially resolved spectroscopy of the globular cluster RZ 2109 and the nature of its black hole

Mark B. Peacock·Stephen E. Zepf·Arunav Kundu·Thomas J. Maccarone·Katherine L. Rhode·John J. Salzer·Christopher Z. Waters·Robin Ciardullo·Caryl Gronwall·Daniel Stern
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Abstract

We present optical HST/STIS spectroscopy of RZ 2109, a globular cluster in the elliptical galaxy NGC 4472. This globular cluster is notable for hosting an ultraluminous X-ray source as well as associated strong and broad [OIII] 4959, 5007 emission. We show that the HST/STIS spectroscopy spatially resolves the [OIII] emission in RZ 2109. While we are unable to make a precise determination of the morphology of the emission line nebula, the best fitting models all require that the [OIII] 5007 emission has a half light radius in the range 3-7 pc. The extended nature of the [OIII] 5007 emission is inconsistent with published models that invoke an intermediate mass black hole origin. It is also inconsistent with the ionization of ejecta from a nova in the cluster. The spatial scale of the nebula could be produced via the photoionization of a strong wind driven from a stellar mass black hole accreting at roughly its Eddington rate.

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Mark B. Peacock, Stephen E. Zepf, Arunav Kundu, Thomas J. Maccarone, Katherine L. Rhode, John J. Salzer, Christopher Z. Waters, Robin Ciardullo, Caryl Gronwall, Daniel Stern. 2012-09-27. Spatially resolved spectroscopy of the globular cluster RZ 2109 and the nature of its black hole. https://doi.org/10.1088/0004-637x/759/2/126

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