1997/07/28 by The MACHO Collaboration, C. Alcock, R. A. Allsman +47
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Gamma-ray bursts and supernovae #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9707311
29 pages including 11 PostScript figures, uses aaspp4.sty. To appear in The Astrophysical Journal
arxiv created 1997/07/28 · openalex publication_date 1997/07/28 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Mean colors and magnitudes of RR Lyrae stars in 24 fields towards the Galactic bulge from the MACHO database are presented. Accurate mean reddenings are computed for these fields on the basis of the mean colors. The distribution along the line of sight of the RR Lyrae population is examined on the basis of the mean magnitudes, and it is shown that the bulk of the RR Lyrae population is not barred. Only the RR Lyrae in the inner fields closer to the Galactic center (l<4, b>-4) show evidence for a bar. The red giant clump stars in the MACHO fields, however, clearly show a barred distribution, confirming the results of previous studies. Given the different spatial distribution, the RR Lyrae and the clump giants trace two different populations. The RR Lyrae would represent the inner extension of the Galactic halo in these fields.