Astron. Astrophys. Suppl. Ser.
Volume 120, Number 2, December I 1996
|Page(s)||207 - 228|
|Published online||15 December 1996|
Optical structure and star formation in blue compact dwarf galaxies. I. Observations and profile decomposition
Universitäts-Sternwarte, Geismarlandstraße 11, D–37083 Göttingen, Germany
2 deceased August 5, 1993
3 Visiting Astronomer at Kitt Peak National Observatory (KPNO), which is operated by AURA, Inc., under contract with the National Science Foundation
4 Astronomy Department, University of Virginia, P.O. Box 3818, University Station, Charlottesville, VA 22903, U.S.A.
Corresponding author: Send offprint request to: e-amil: email@example.com
Accepted: 16 April 1996
We present new B and R CCD surface photometry for a sample of 4 Blue Compact Dwarf Galaxies (BCDs) and 2 higher luminosity starburst galaxies. We find that the BCD surface brightness profiles (SBPs) can be generally well fitted by the sum of the light of 3 distinct components: 1) an exponential component at large radii, with or without a central flattening which describes the underlying older stellar population; 2) a plateau component at intermediate radii and 3) a gaussian component at small radii. The last 2 components describe the ongoing starburst superimposed on the older stellar component. We apply the 3–component decomposition scheme to 8 more BCDs from the literature and, for the total sample of 14 galaxies, derive structural properties such as central surface brightness and scale length, and perform a deprojection to obtain the luminosity density distribution for each component. We also derive color profiles and find that BCDs show generally a reddening outwards, followed by a blueing beyond a transition radius.
Key words: galaxies: compact; photometry; structure; fundamental parameters
© European Southern Observatory (ESO), 1996