Issue |
Astron. Astrophys. Suppl. Ser.
Volume 129, Number 2, April II 1998
|
|
---|---|---|
Page(s) | 313 - 328 | |
DOI | https://doi.org/10.1051/aas:1998398 | |
Published online | 15 April 1998 |
Structure and stellar content of dwarf galaxies*
I. B and R photometry of dwarf galaxies in the M 81 group
1
Astronomical Institute, University of Basel, Venusstrasse 7, CH-4102 Binningen, Switzerland
2
Observatoire de Lyon, F-64561 St. Genis-Laval Cedex, France
Send offprint request to: T. Bremnes, e-mail: brem nes@astro.uni bas.ch
Received:
4
September
1997
Accepted:
22
September
1997
We have carried out CCD photometry in the Cousins B and R bands of 25 dwarf
galaxy members and suspected members of the M 81 group of galaxies.
Based on azimuthally averaged brightness profiles we have derived total
magnitudes, effective radii, effective surface brightnesses, as well as galaxy
diameters at various isophotal levels in both photometric bands. Best-fitting
exponential parameters and colour gradients are also given for these
galaxies. The data will be interpreted, along with those of another
supplementary paper, in Paper III of this series (to appear in the main
journal).
In two appendices we discuss the nature of a clustering of unusual low-surface
brightness objects in the south-east corner of the M 81 group and show
the luminosity function of its presently known members.
Key words: galaxies: general / galaxies: fundamental parameters / galaxies: photometry / galaxies: irregular / galaxies: clusters: M 81 group
© European Southern Observatory (ESO), 1998