Bibcode
Amorín, R. O.; Muñoz-Tuñón, C.; Aguerri, J. A. L.; Cairós, L. M.; Caon, N.
Bibliographical reference
Astronomy and Astrophysics, Volume 467, Issue 2, May IV 2007, pp.541-558
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5
2007
Journal
Citations
40
Refereed citations
34
Description
Context: The structural properties of the low surface brightness stellar
host in blue compact dwarf galaxies are often studied by fitting
r1/n models to the outer regions of their radial profiles.
The limitations imposed by the presence of a large starburst emission
overlapping the underlying component makes this kind of analysis a
difficult task. Aims: We propose a two-dimensional fitting
methodology in order to improve the extraction of the structural
parameters of the LSB host. We discuss its advantages and weaknesses by
using a set of simulated galaxies and compare the results for a sample
of eight objects with those already obtained using a one-dimensional
technique. Methods: We fit a PSF convolved Sérsic model to
synthetic galaxies, and to real galaxy images in the B, V, R filters. We
restrict the fit to the stellar host by masking out the starburst region
and take special care to minimize the sky-subtraction uncertainties. In
order to test the robustness and flexibility of the method, we carry out
a set of fits with synthetic galaxies. Furthermore consistency checks
are performed to assess the reliability and accuracy of the derived
structural parameters. Results: The more accurate isolation of
the starburst emission is the most important advantage and strength of
the method. Thus, we fit the host galaxy in a range of surface
brightness and in a portion of area larger than in previous published 1D
fits with the same dataset. We obtain robust fits for all the sample
galaxies, all of which, except one, show Sérsic indices n very
close to 1, with good agreement in the three bands. These findings
suggest that the stellar hosts in BCDs have near-exponential profiles, a
result that will help us to understand the mechanisms that form and
shape BCD galaxies, and how they relate to the other dwarf galaxy
classes.