[SEMINARI] Stellar density and kinematics in the central parsec of the Galaxy, Rainer Schödel

[Enric Marco]

Stellar density and kinematics in the central parsec of the Galaxy

Dr. Rainer Schödel

Instituto de Astrofísica de Andalucía

Lloc: Seminari del departament d'Astronomia i Astrofísica

Dia: Divendres 27 novembre 2009

Hora: 12:00

Resum

The center of the Milky Way is a unique laboratory to study the 
structure and dynamics of a dense stellar cluster surrounding a massive 
black hole. At the Galactic center, we find the combination of nuclear 
cluster plus central black hole that is typical for spiral galaxies. 
While we can only study the integrated light in the case of the barely 
resolved  extragalactic nuclear star clusters, the Milky Way is 
currently the only case, in which the structure of the cluster can be 
analyzed in detail, i.e. both stellar densities and dynamics can be 
probed directly, via measurements on individual stars. In this talk we 
will focus on recent research on the Milky Way nuclear star cluster.  
Recent measurement of stellar dynamics out to a projected distance of 1 
pc from the black hole have lead to the first direct measurement of the 
enclosed extended, i.e. non-black hole, mass in the central parsec. We 
have also identified the reason why the black hole mass was 
underestimated by a factor of ~2 before orbital measurements became 
available. Perhaps one of the greatest current enigmas is the absence of 
a stellar cusp around the black hole. While a cusp is a solid prediction 
from theory, recent observations confirm that it is absent, at least in 
the stellar population that can be analyzed with current 
instrumentation. We will discuss the currently suggested explanations 
for this finding.

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 Dr. Enric Marco
 Departament d'Astronomia i Astrofísica
 Facultat de Física
 Universitat de València
 C/  Dr. Moliner, 50
 46100 Burjassot, Spain
 Phone: (34)-96-354-3069
 Fax:(34)-96-354-3084
 enric.marco en uv.es
 http://www.uv.es/marco
 http://www.uv.es/aulaastronomia
 http://www.uv.es/daa
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