2004/07/16 by S. Picaud, A. C. Robin · 3 citations
Physics and Astronomy · Social Sciences · #Astrophysics and Star Formation Studies #Educational Leadership and Practices #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1051/0004-6361:20041218
published as Astron.Astrophys. 428 (2004) 891-903 · 17 pages, 12 figures, accepted for publication by A&A
arxiv created 2004/07/16 · openalex publication_date 2004/12/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
We attempt to study the characteristics of the different stellar populations present in the Galactic central region. A Monte Carlo method is used to simultaneously fit 11 thin disc and triaxial outer bulge density parameters on (Ks, ) star count data in almost 100 windows from the DENIS near infrared large scale survey at -8° < l < 12° and b < 4°. Various bulge density profiles and luminosity functions were tested using a population synthesis scheme. The best models, selected by a maximum likelihood test, give the following description: the outer bulge is boxy, prolate, and oriented 10.6° ± 3° with respect to the Sun-center direction. It seems that the main bulge population is not older than 10 Gyr, but this preliminary result needs further work to be confirmed. A significant central hole is found in the middle of the thin disc. We discuss these results in regard to previous findings and the scenario of bulge formation.