| Irfu-10-34
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| Radio observations of NGC 6388 : an upper limit on the mass of its central black hole |
| D. Cseh, P. Kaaret, S. Corbel, E. Körding, M. Coriat, A. Tzioumis, B. Lanzoni |
| We present the results of deep radio observations with the Australia Telescope Compact
Array (ATCA) of the globular cluster NGC 6388. We show that there is no radio
source detected (with a r.m.s. noise level of 27 µJy) at the cluster centre of gravity or
at the locations of the any of the Chandra X-ray sources in the cluster. Based on the
fundamental plane of accreting black holes which is a relationship between X-ray luminosity,
radio luminosity and black hole mass, we place an upper limit of 1500 M?
on the mass of the putative intermediate-mass black hole located at the centre of NGC
6388. We discuss the uncertainties of this upper limit and the previously suggested
black hole mass of 5700 M? based on surface density profile analysis. |
