2005/07/01 by Н. А. Тихонов, N. A. Tikhonov · 2 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Disc #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Lenticular galaxy #Luminous infrared galaxy #Peculiar galaxy #Physics #Spiral galaxy #Stellar, planetary, and galactic studies #Surface brightness fluctuation #astro-ph
paper · pdf · doi:10.1134/1.1985947
published as Astron.Rep. 49 (2005) 501-509 · 12 pages, 4 figures
openalex publication_date 2005/07/01 · arxiv created 2006/10/17 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Stellar photometry of nearby irregular galaxies of the Local Group is used to identify and study the young and old stellar populations of these galaxies. An analysis of the spatial distributions of stars of different ages in face-on galaxies shows that the young stellar populations in irregular galaxies are concentrated toward the center, and form local inhomogeneities in star-forming regions, while the old stellar populations—red giants—form extended structures around the irregular galaxies. The sizes of these structures exceed the visible sizes of the galaxies at the 25 m /arcsec 2 isophote by a factor of two to three. The surface density of the red giants decreases exponentially from the center toward the edge, similar to the disk components in spiral galaxies.