Radio observations of NGC 6388: an upper limit on the mass of its central black hole

• Published in: Monthly notices of the Royal Astronomical Society Vol. 406; no. 2; pp. 1049 - 1054
• Main Authors: Cseh, D., Kaaret, P., Corbel, S., Körding, E., Coriat, M., Tzioumis, A., Lanzoni, B.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-08-2010; Wiley-Blackwell; Oxford University Press
• Subjects: accretion; accretion disks; accretion, accretion disks; Arrays; Astronomy; black hole physics; Black holes; Black holes (astronomy); Centre of gravity; Clusters; Density; Earth, ocean, space; Exact sciences and technology; globular clusters: general; globular clusters: individual: NGC 6388; Indexing in process; Luminosity; Radio; Radio astronomy; radio continuum: general; Radio observation; Space telescopes; radio continuum: general; black hole physics; accretion, accretion disks; globular clusters: general; globular clusters: individual: NGC 6388; Uncertainty; Black holes; Luminosity; Globular clusters; Star clusters; Accretion disks; Radio observation; Continuum; Upper bound; Cosmology; Gravity
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2010.16726.x

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 an rms noise level of 27 μJy) at the cluster centre of gravity or at the locations of 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 based on surface density profile analysis.