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Дата изменения: Mon Jun 28 14:47:36 2004 Дата индексирования: Tue Oct 2 02:38:13 2012 Кодировка: Поисковые слова: m 8 |
CCD imaging and photometry of large BCGs subsample |
For many problems connected with study both group and individual properties of blue compact galaxies (BCGs), it is important to know their photometric and structure parameters. In particular, this is necessary for study possible evolution connections of BCGs with other types of low-mass galaxies. For the study of BCG phenomenon it is important to probe possible relations between the main physical parameters of this galaxies such as luminosity, characteristic size, gas mass, color indexes, etc. For this work it is very important to deal with well selected samples.
As a first step in this direction BVR images of 68 BCGs obtained with Bologna University 1.52-m telescope have been reduced. The galaxies are selected from the zone of Second Byurakan survey and Markarian catalog..
Surface brightness and color index profiles along the effective radius are derived, and the estimates of linear size and total magnitudes are presented. Observational and derived parameters of studied BCGs vary in broad range, what seemingly indicates on homogenious content of the sample. So absolute B-magnitudes of studied galaxies are in the range -19.5^m - -13.5^m. The color index B-V varies in between 0.3^m - 1.0^m. The linear size of galaxies at the surface brightness level mu(B) = 25^m/(arcsec)^2 varies between 0.5 and 7 kpc.
The studies BCGs show variuos morphologies: 27 of them resemble dE galaxies, and 31 ones - dIrr galaxies. 10 BCGs are very compact and hard to classify.
In figure the CCD-images of galaxies Mrk 1039 and SBS 0743+591B are shown in V-band. Isophote maps, one-dimensional surface brightness profiles and color index B-V shown as well. Results of profile decomposition in V-band are presented for two components - external exponential disk and central brighter gaussian.
Copy of this figures in PostScript file (60Kb)
2 April 1999