NO EXCESS OF RR LYRAE STARS IN THE CANIS MAJOR OVERDENSITY
- Centro de Investigaciones de AstronomIa (CIDA), Apartado Postal 264, Merida 5101-A (Venezuela, Bolivarian Republic of)
Our multi-epoch survey of {approx}20 deg{sup 2} of the Canis Major (CMa) overdensity has detected only 10 RR Lyrae stars (RRLS). We show that this number is consistent with the number expected from the Galactic halo and thick disk populations alone, leaving no excess that can be attributed to the dwarf spheroidal (dSph) galaxy that some authors have proposed as the origin of the CMa overdensity. If this galaxy resembles the dSph satellites of the Milky Way (MW) and of M31 and has the putative M{sub V} {approx} -14.5, our survey should have detected several tens of RRLS. Even if M{sub V} {approx}< -12, the expected excess is {approx}>10, which is not observed. Either the old stellar population of this galaxy has unique properties or, as others have argued before, the CMa overdensity is produced by the thin and thick disk and spiral arm populations of the MW and not by a collision with a dSph satellite galaxy.
- OSTI ID:
- 21269175
- Journal Information:
- Astronomical Journal (New York, N.Y. Online), Vol. 137, Issue 5; Other Information: DOI: 10.1088/0004-6256/137/5/4412; Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
Similar Records
RR LYRAE VARIABLES IN M33. II. OOSTERHOFF PROPERTIES AND RADIAL TRENDS
EXPLORING THE SAGITTARIUS STREAM WITH SEKBO SURVEY RR LYRAE STARS