Bibcode
Méndez, R. A.; Costa, E.; Pedreros, M. H.; Gallart, C.
Bibliographical reference
XI IAU Regional Latin American Meeting of Astronomy (Eds. L. Infante & M. Rubio) Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias) Vol. 26, pp. 183
Advertised on:
6
2006
Citations
0
Refereed citations
0
Description
We present a progress report on a project aimed at determining the
absolute proper motion of the Small Magellanic Cloud (SMC), with respect
to background Quasi Stellar Objects (QSOs) that can be used as fiducial
reference points (Anguita et al. 2000, Pedreros et al. 2002, Pedreros et
al. 2005). The motions thus derived, when combined with existing radial
velocities, will allow us to determine the space velocity vectors of the
satellite of our galaxy, which in turn will place important constraints
on its orbit. This knowledge is crucial to determine if the SMC is
gravitationally bound to the Galaxy, and to our understanding of the
evolution and origin of the Magellanic System.
In general, the proper motions of the satellites of our Galaxy are
necessary to understand: a) the origin of the Milky Way (MW) satellite
system and its relationship with the formation of the galactic halo, b)
the nature and origin of the streams that seem to align different
subgroups of these galaxies, and c) the role of tidal interactions in
the evolution and star formation history of low mass galaxies.
Using the Las Campanas Observatory (LCO) du Pont 2.5-m telescope and a
CCD we expect to achieve, on a time-base of five years, and with six
epochs of observations (of which four epochs have already been
successfully secured, and a fifth has been granted for late 2005), a
proper motion precision of 0.8 mas/year (1 mas = 1 milli-arc-sec) per
QSO, for the SMC, on 10 QSO fields. This precision is sufficient to
address the specific problem of reconstructing the past and predicting
the future orbit of the SMC.
A comprehensive study of the MC-MW system can lead to a greater
understanding of galaxy evolution and the physical processes governing
star formation in galaxies, and provide us with insights into the role
of galaxy interactions in stimulating star formation. In addition, the
MCs may also hold important clues to understand the formation of the MW
halo.