2005/10/20 by N. Matsunaga, H. Fukushi, Y. Nakada · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Asymmetry #Brightness #Bulge #Cosmic dust #Milky Way #Stars #Stellar, planetary, and galactic studies #Surface brightness #Variable star #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2005.09556.x
published as Mon.Not.Roy.Astron.Soc.364:117-125,2005 · 10 pages, 16 figures, published in MNRAS. Added note in proof
openalex publication_date 2005/10/20 · arxiv created 2005/12/04 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We have extracted a total of 1968 Mira variables from the Optical Gravitational Lensing Experiment II (OGLE-II) data base in the Galactic bulge region. Among them, 1960 are associated with 2 Micron All-sky Survey (2MASS) sources, and 1541 are further identified with Midcourse Space Exploration (MSX) point sources. Their photometric properties are compared with those of Mira variables in the Large and Small Magellanic Clouds. We have found that mass-losing stars with circumstellar matter are reddened such that the colour dependence of the absorption coefficient is similar to that of interstellar matter. We also discuss the structure of the bulge. The surface number density of the bulge Mira variables is well correlated with the 2.2-μm surface brightness obtained by the Cosmic Background Explorer (COBE) satellite. Using this relation, the total number of Mira variables in the bulge is estimated to be about 6 × 105. The log P−K relation of the Mira variables gives their space distribution which supports the well-known asymmetry of the bar-like bulge.