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arXiv · 1007.4559

VLT Kinematics for omega Centauri: Further Support for a Central Black Hole

Eva Noyola·Karl Gebhardt·Markus Kissler-Patig·Nora Lutzgendorf·Behrang Jalali·P. Tim de Zeeuw·Holger Baumgardt
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Abstract

The Galactic globular cluster omega Centauri is a prime candidate for hosting an intermediate mass black hole. Recent measurements lead to contradictory conclusions on this issue. We use VLT-FLAMES to obtain new integrated spectra for the central region of omega Centauri. We combine these data with existing measurements of the radial velocity dispersion profile taking into account a new derived center from kinematics and two different centers from the literature. The data support previous measurements performed for a smaller field of view and show a discrepancy with the results from a large proper motion data set. We see a rise in the radial velocity dispersion in the central region to 22.8+-1.2 km/s, which provides a strong sign for a central black hole. Isotropic dynamical models for omega Centauri imply black hole masses ranging from 3.0 to 5.2x10^4 solar masses depending on the center. The best-fitted mass is 4.7+-1.0x10^4 solar masses.

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Eva Noyola, Karl Gebhardt, Markus Kissler-Patig, Nora Lutzgendorf, Behrang Jalali, P. Tim de Zeeuw, Holger Baumgardt. 2010-07-26. VLT Kinematics for omega Centauri: Further Support for a Central Black Hole. https://doi.org/10.1088/2041-8205%2F719%2F1%2Fl60

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