Searching for intermediate mass black holes: understanding the data first
arXiv:1501.04114 · doi:10.1017/S174392131500784X
Abstract
The detection of intermediate mass black holes (IMBHs) in globular clusters has been hotly debated, with different observational methods delivering different outcomes for the same object. In order to understand these discrepancies, we construct detailed mock integral field spectroscopy (IFU) observations of globular clusters, starting from realistic Monte Carlo cluster simulations. The output is a data cube of spectra in a given field-of-view that can be analyzed in the same manner as real observations and compared to other (resolved) kinematic measurement methods. We show that the main discrepancies arise because the luminosity-weighted IFU observations can be strongly biased by the presence of a few bright stars that introduce a scatter in velocity dispersion measurements of several km/s. We show that this intrinsic scatter can prevent a sound assessment of the central kinematics, and therefore should be fully taken into account to correctly interpret the signature of an IMBH.
4 pages, 2 figures. To be published in the Proceedings IAU Symposium No. 312, Star Clusters and Black Holes in Galaxies and Across Cosmic Time
References in corpus (5)
- GALEV evolutionary synthesis models - I. Code, input physics and web-interface
- The velocity dispersion profile of NGC 6388 from resolved-star spectroscopy: no evidence of a central cusp and new constraints on the black hole mass
- Rotating Globular Clusters
- Central rotations of Milky Way Globular Clusters
- The central mass and mass-to-light profile of the Galactic globular cluster M15