Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-01-14
Astronomy and Astrophysics
Astrophysics
9 pages, 12 eps figures (some of them somewhat degraded in resolution), accepted for publication in MNRAS
Scientific paper
10.1111/j.1365-2966.2008.12953.x
We performed a photometric multicolor survey of the core of the Canis Major over-density at l 244, -8.0, reaching V = 22 and covering 0.3 x 1 degree. The main aim is to unravel the complex mixture of stellar populations toward this Galactic direction, where in the recent past important signatures of an accretion event have been claimed to be detected. While our previous investigations were based on disjointed pointings aimed at revealing the large scale structure of the third Galactic Quadrant, we now focus on a complete coverage of a smaller field centered on the Canis Major over-density. A large wave-length baseline, in the UBVRI bands, allows us to build up a suite of colour colour and colour magnitude diagrams, providing a much better diagnostic tool to disentangle the stellar populations of the region. In fact, the simple use of one colour magnitude diagram, widely employed in all the previous studies defending the existence of the Canis Major galaxy, does not allow one to separate the effects of the different parameters (reddening, age, metallicity, and distance) involved in the interpretation of data, forcing to rely on heavy modeling. In agreement with our previous studies in the same general region of the Milky Way, we recognize a young stellar population compatible with the expected structure and extension of the Local (Orion) and Outer (Norma-Cygnus) spiral arms in the Third Galactic Quadrant. Moreover we interpret the conspicuous intermediate-age metal poor population as belonging to the Galactic thick disk, distorted by the effect of strong disk warping at this latitude, and to the Galactic halo.
Carraro Giovanni
Moitinho Andre
Vazquez Ruben A.
No associations
LandOfFree
Stellar populations in the Canis Major over-density does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Stellar populations in the Canis Major over-density, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stellar populations in the Canis Major over-density will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-634525