Distribution and studies of the infrared stellar population in the Galaxy. III. Baade's window photometry.
Abstract
An infrared scan of the Baade Window (BW) area is obtained. The Cumulative K-Counts Function (hereafter CCF) is decomposed into disk-CCF and bulge-CCF components. The bulge-CCF is steeper than the disk-CCF showing a relative depletion of high mass stars with respect to the disk. The contribution of the bulge component towards BW is significant only at K ≡ +8.0 or fainter magnitudes; the bright end of the CCF is dominated by the disk. The bulge-CCF is compared with CCFs for the globular clusters 47 Tuc, M92, M3 and M13 and for the open cluster M67. The similarity of the slope of the bulge-CCF to those of the globular clusters suggests that the stellar population of the bulge may be similar in age and perhaps metallicity characteristics to the stellar population in globular clusters. Photometric studies of a bright-K subsample are made. Several sources with mild IR-Excesses are found and are confirmed as Mira variables. The majority of the sources lie along the reddening line at E(J-K) = 0.27 from the solar neighbourhood intrinsic giant sequence. In an HR diagram most of the sources lie above the giant branch tips of ω-Cen, 47 Tuc and M92. This also suggests that their metallicity may lie in the range between that of M92 and 47 Tuc.
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- April 1992
- Bibcode:
- 1992A&AS...93...61R
- Keywords:
-
- Infrared Stars;
- Milky Way Galaxy;
- Star Distribution;
- Stellar Spectrophotometry;
- Calibrating;
- Galactic Bulge;
- Open Clusters;
- Stellar Magnitude;
- Telescopes