2007/07/23 by Luz M. Cairos, L. M. Cairós, Nicola Caon +11 · 3 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Dwarf galaxy #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Photometry (optics) #Physics #Population #Star formation #Stars #Stellar population #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/521615
21 pages, 13 figures. Accepted for publication in ApJ, tentatively scheduled for the ApJ November 1, 2007 v669n1 issue
arxiv created 2007/07/23 · openalex publication_date 2007/11/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present results from a detailed spectrophotometric analysis of the blue compact dwarf galaxy Mrk 35 (Haro 3), based on deep optical ( BVRI ) and near-IR ( JHK ) imaging, Hα narrowband observations, and long-slit spectroscopy. The optical emission of the galaxy is dominated by a central young starburst, with a barlike shape, while an underlying component of stars, with elliptical isophotes and red colors, extends more than 4 kpc from the galaxy center. High-resolution Hα and color maps allow us to identify the star-forming regions, to spatially discriminate them from the older stars, and to recognize several dust patches. We derive colors and Hα parameters for all the identified star-forming knots. Observables derived for each knot are corrected for the contribution of the underlying older stellar population, the contribution by emission lines, and from interstellar extinction, and compared with evolutionary synthesis models. We find that the contributions of these three factors are by no means negligible and that they significantly vary across the galaxy. Therefore, careful quantification and subtraction of emission lines, galaxy host contribution, and interstellar reddening at every galaxy position are essential to derive the properties of the young stars in blue compact dwarfs. We find that we can reproduce the colors of all the knots with an instantaneous burst of star formation and the Salpeter initial mass function with an upper mass limit of 100 M ☉ . In all cases the knots are just a few Myr old. The underlying population of stars has colors consistent with being several Gyr old.