Density and kinematic cusps in M54 at the heart of the Sagittarius dwarf galaxy: evidence for a 10^4 M_sun Black Hole?

Abstract

We report the detection of a stellar density cusp and a velocity dispersion increase in the center of the globular cluster M54, located at the center of the Sagittarius dwarf galaxy (Sgr). The central line of sight velocity dispersion is 20.2 +/- 0.7 km/s, decreasing to 16.4 +/- 0.4 km/s at 2.5" (0.3 pc). Modeling the kinematics and surface density profiles as the sum of a King model and a point-mass yields a black hole (BH) mass of ~ 9400 M_sun. However, the observations can alternatively be explained if the cusp stars possess moderate radial anisotropy. A Jeans analysis of the Sgr nucleus reveals a strong tangential anisotropy, probably a relic from the formation of the system.

Accepted for publication by The Astrophysical Journal (Letters). Latex. 5 pages, 4 color figures, 2 with reduced resolution, one in greyscale. A full-resolution color version of the paper can be retrieved from http://www.bo.astro.it/SGR/Sgr_BH.pdf

References in corpus (6)

• Gemini and Hubble Space Telescope Evidence for an Intermediate Mass Black Hole in omega Centauri
• The nucleus of the Sagittarius dSph galaxy and M54: a window on the process of galaxy nucleation
• The surface density profile of NGC 6388: a good candidate for harboring an intermediate-mass black hole
• The presence of intermediate-mass black holes in globular clusters and their connection with extreme horizontal branch stars
• Radio observations of NGC 2808 and other globular clusters: constraints on intermediate mass black holes
• A search for stellar X-ray sourcesin the Sagittarius and Carina dwarf galaxies - I: X-ray observations

Cited by in corpus (34)

• Intermediate-Mass Black Holes
• Nuclear Star Clusters
• Observational evidence for intermediate-mass black holes
• N-body modeling of globular clusters: Masses, mass-to-light ratios and intermediate-mass black holes
• Improved Dynamical Constraints on the Masses of the Central Black Holes in Nearby Low-mass Early-type Galactic Nuclei And the First Black Hole Determination for NGC 205
• Hubble Space Telescope proper motion (HSTPROMO) catalogs of Galactic globular clusters. II. Kinematic profiles and maps
• On the coexistence of stellar-mass and intermediate-mass black holes in globular clusters
• The Accreted Nuclear Clusters of the Milky Way
• Scientific Potential of DECIGO Pathfinder and Testing GR with Space-Borne Gravitational Wave Interferometers
• Chemical abundances in the nucleus of the Sagittarius dwarf spheroidal galaxy
• A deep view into the nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. I. Data and stellar population characterization
• Detection of a $\sim$100,000 M${}_{\odot }$ black hole in M31's most massive globular cluster: A tidally stripped nucleus
• A deep view into the nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. II. Kinematic characterization of the stellar populations
• Discovery of a double sequence of blue straggler stars in the core-collapsed globular cluster NGC 6256
• A consistency-test for determining whether ultra-compact dwarf galaxies could be the remnant nuclei of threshed galaxies
• The GALAH survey: Tracing the Milky Way's formation and evolution through RR Lyrae stars
• A mass estimate of an intermediate-mass black hole in omega Centauri
• The metallicity distribution in the core of the Sagittarus dwarf spheroidal: minimising the metallicity biases
• Efficiency of black hole formation via collisions in stellar systems: An analysis of data from simulations and observations
• A Deep View into the Nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. III. Discrete multi-component population-dynamical models based on the Jeans equations
• Testing for Dark Matter in the Outskirts of Globular Clusters
• The Dark Matter Halo of M54
• On the gamma-ray emission from the core of the Sagittarius dwarf galaxy
• Collisionless dynamics in Globular Clusters
• A Photometric in-depth look at the core-collapsed globular cluster NGC 6284
• Relativistic scattering of a fast spinning neutron star by a massive black hole
• An ongoing tidal capture in the Large Magellanic Cloud: the low-mass star cluster KMK88-10 captured by the massive globular cluster NGC 1835?
• A Chandra Survey of Milky Way Globular Clusters. III. Searching for X-ray Signature of Intermediate-mass Black Holes
• The dynamical age of the LMC globular cluster NGC 1835 using the "dynamical clock"
• Globular cluster candidates in the Sagittarius dwarf galaxy
• Proper Motions and Internal Dynamics in the Core of the Globular Cluster M71
• FROST-CLUSTERS -- III. Metallicity-dependent intermediate mass black hole formation by runaway collisions in dense star clusters
• A Search for Wandering Black Holes in the Milky Way with Gaia and DECaLS
• Resolved nuclear kinematics link the formation and growth of nuclear star clusters with the evolution of their early and late-type hosts