R. Ibata et al 2009 ApJ 699 L169 doi:10.1088/0004-637X/699/2/L169
DENSITY AND KINEMATIC CUSPS IN M54 AT THE HEART OF THE SAGITTARIUS DWARF GALAXY: EVIDENCE FOR A 104 M ☉ BLACK HOLE?
FREE ISSUER. Ibata1, M. Bellazzini2, S. C. Chapman3, E. Dalessandro4, F. Ferraro4, M. Irwin3, B. Lanzoni4, G. F. Lewis5, A. D. Mackey6, P. Miocchi4 and A. Varghese1
Show affiliationsWe 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-1, decreasing to 16.4 ± 0.4 km s-1 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 mass of ~9400 M ☉. 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.
- Keywords
black hole physics; globular clusters: individual (M54); stellar dynamics
- PACS
-
98.62.Js Galactic nuclei (including black holes), circumnuclear matter, and bulges
98.10.+z Stellar dynamics and kinematics
98.20.Jp Globular clusters in external galaxies
98.62.Lv Stellar content and populations; radii; morphology and overall structure
98.52.Wz Dwarf galaxies (elliptical, irregular, and spheroidal)
- Subjects
- Dates
-
Issue 2 (2009 July 10)
Received 2009 April 21, accepted for publication 2009 June 2
Published 2009 June 25
-
Density and Kinematic Cusps in M54 at the Heart of the Sagittarius Dwarf Galaxy: Evidence for A 104 M ☉ Black Hole?
R. Ibata et al 2009 ApJ 699 L169
-
Strong friction of silicon carbide nanowire films
Hyun Woo Shim et al 2009 Nanotechnology 20 025704
-
Lunar Outgassing, Transient Phenomena, and the Return to the Moon. I. Existing Data
Arlin P. S. Crotts 2008 ApJ 687 692
-
Transient Lunar Phenomena: Regularity and Reality
Arlin P. S. Crotts 2009 ApJ 697 1
-
Enhanced release of liquid from carbon nanotubes due to entrainment by an air layer
S Sinha Ray et al 2009 Nanotechnology 20 095711
-
Static spike autosolitons in the Gray-Scott model
C B Muratov and V V Osipov 2000 J. Phys. A: Math. Gen. 33 8893
-
Calibration and testing of the ST7 capacitive sensor using an optical interferometer with fiber optic input and output
G Allen et al 2006 J. Phys.: Conf. Ser. 32 117
-
High-stability temperature control for ST-7/LISA Pathfinder gravitational reference sensor ground verification testing
S Higuchi et al 2006 J. Phys.: Conf. Ser. 32 125
-
Models of permeation in ion channels
Serdar Kuyucak et al 2001 Rep. Prog. Phys. 64 1427
-
JAIDA, JAS3, WIRED4 and the AIDA tag library — experience and new developments
M Donszelmann et al 2008 J. Phys.: Conf. Ser. 119 032016
Related review articles
What's this?- Magnetohydrodynamic models of astrophysical jets
- Gravitational lensing
- Physical conditions in potential accelerators of ultra-high-energy cosmic rays: updated Hillas plot and radiation-loss constraints