1999/06/24 by A. Zurita, Almudena Zurita, M. Rozas +3 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Bar (unit) #Barred spiral galaxy #Dust lane #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #Spiral (railway) #Spiral galaxy #Star formation #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1023/a:1017500812701
published as Astrophys.Space Sci. 276 (2001) 491-498 · 8 pages, 7 figures. To appear in A&SS, in press.(Euroconference, "The Evolution of Galaxies on Cosmological Timescales", Eds. Beckman and Mahoney)
arxiv created 1999/06/24 · openalex publication_date 2001/03/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We use the catalogue of HII regions obtained from a high quality continuum-subtracted Hα image of the grand design spiral galaxy NGC 7479, to construct the luminosity function (LF) for the HII regions (over 1000) of the whole galaxy. Although its slope is within the published range for spirals of the same morphological type, the unusually strong star formation along the intense bar of NGC 7479 prompted us to analyze separately the HII regions in the bar and in the disc. We have calculated the physical properties of a group of HII regions in the bar and in the disc selected for their regular shapes and absence of blending. We have obtained galaxy-wide relations for the HII region set: diameter distribution function and also the global Hα surface density distribution. As found previously for late-type spirals, the disc LF shows clear double-linear behaviour with a break at log LHα=38.6 (in erg/s). The bar LF is less regular. This reflects a physical difference between the bar and the disc in the properties of their populations of regions.