The 1 to 2.5 mu broad band emission of Blue Compact Dwarf Galaxies

Citation
V. Doublier et al., The 1 to 2.5 mu broad band emission of Blue Compact Dwarf Galaxies, ASTRON ASTR, 367(1), 2001, pp. 33-45
Citations number
33
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMY AND ASTROPHYSICS
ISSN journal
00046361 → ACNP
Volume
367
Issue
1
Year of publication
2001
Pages
33 - 45
Database
ISI
SICI code
0004-6361(200102)367:1<33:T1T2MB>2.0.ZU;2-A
Abstract
We present J, H and K surface photometry of 12 Blue Compact Dwarf Galaxies (BCDGs) selected from the southern sample (Doublier et al. 1999). A systema tic excess of light in the K band with respect to the other bands in the vi sible and the near infrared is observed, indicating, since nebular emission is negligible, that a stellar population of red giants dominates the globa l flux from the galaxy. Moreover, comparisons of the metallicity-color rela tions of BCDGs and globular clusters show very little differences, indicati ng that BCDGs are most probably old, in the cosmological sense, systems. Lo cal colors of the star forming regions show that these regions are indeed v ery young and possibly coeval across the galaxy when several starburst loca tions exist. At least 4 BCDGs (UM 465A and B, Haro 14 and Tololo 0610-378) show evidence of the presence of young red supergiant stars. The light dist ributions in the J, H and K bands are generally consistent with those in th e optical, the differences are discussed. We confirm that our optical photo metric classification remains valid in the near infrared. Thus, the global light distribution in the galaxy is an intrinsic property of the host galax y independent of the presence of the starburst.