Bibcode
San Roman, Izaskun; Sarajedini, Ata; Aparicio, A.
Bibliographical reference
The Astrophysical Journal, Volume 720, Issue 2, pp. 1674-1683 (2010).
Advertised on:
9
2010
Journal
Citations
31
Refereed citations
29
Description
We present a catalog of 2990 extended sources in a 1° × 1°
area centered on M33 using the MegaCam camera on the 3.6 m
Canada-France-Hawaii Telescope. The catalog includes 599 new candidate
stellar clusters, 204 previously confirmed clusters, 1969 likely
background galaxies, and 218 unknown extended objects. We present ugriz
integrated magnitudes of the candidates and confirmed star clusters
(SCs) as well as the full width at half maximum, ellipticity, and
stellarity. Based on the properties of the confirmed SCs, we select a
sub-sample of highly probable clusters composed of 246 objects. The
integrated photometry of the complete cluster catalog reveals a wide
range of colors of -0.4 < (g - r) < 1.5 and -1.0 < (r - i) <
1.0 with no obvious cluster subpopulations. Comparisons with models of
simple stellar populations suggest a large range of ages some as old as
~10 Gyr. In addition, we find a sequence in the color-color diagrams
that deviates from the expected direction of evolution. This feature
could be associated with very young clusters (<107 yr)
possessing significant nebular emission. Analysis of the radial density
distribution suggests that the cluster system of M33 has suffered from
significant depletion possibly due to interactions with M31. We also
detect a gap in the cluster distribution in the color-color diagram at
(g - r) ~= 0.3 and (u - g) ~= 0.8. This gap could be interpreted as an
evolutionary effect. This complete catalog provides promising targets
for deep photometry and high-resolution spectroscopy to study the
structure and star formation history of M33.
Based on observations obtained with MegaPrime/MegaCam, a joint project
of the Canada-France-Hawaii Telescope (CFHT) and CEA/DAPNIA at the CFHT,
which is operated by the National Research Council (NRC) of Canada, the
Institut National des Science de l'Univers of the Centre National de la
Recherche Scientifique (CNRS) of France, and the University of Hawaii.
Related projects
Milky Way and Nearby Galaxies
The general aim of the project is to research the structure, evolutionary history and formation of galaxies through the study of their resolved stellar populations, both from photometry and spectroscopy. The group research concentrates in the most nearby objects, namely the Local Group galaxies including the Milky Way and M33 under the hypothesis
Martín
López Corredoira