| Issue |
Astron. Astrophys. Suppl. Ser.
Volume 145, Number 2, August 2000
|
|
|---|---|---|
| Page(s) | 229 - 242 | |
| DOI | https://doi.org/10.1051/aas:2000239 | |
| Published online | 15 August 2000 | |
A search for LSB dwarf galaxies in the M 81 group on digitally stacked Schmidt plates *
Thüringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenburg, Germany e-mail: frobrich@tls-tautenburg.de/meus@tls-tautenburg.de
Send offprint request to: H. Meusinger
Received:
21
December
1999
Accepted:
18
May
2000
We present a search for low surface brightness
(LSB) dwarf galaxies in a region of
10 square degrees around M 81.
The survey is based on the digital co-addition of
Schmidt plates where algorithms for sub-arcsecond co-centering,
quality-weighting and sigma-clipping “bad pixel” rejection
are applied. The 3 σ surface brightness limit is
. In a substantial
fraction of the surveyed area, the detection of LSB objects
is limited by “Galactic cirrus” rather than by the
limiting magnitude of the stacked image.
Optimum search parameters for an automated detection of dwarf
galaxies are derived from simulations. The final selection of
LSB dwarf candidates relies on a combination of automated
detection and visual inspection.
We present six new dwarf galaxy candidates with
. Photometric data
and best fitting parameters for the exponential model are
derived both for the new candidates and for some previously
known LSB dwarf galaxies in the field. For the most likely
new dwarf member of the M 81 group, a central
surface brightness of 
and a scale-length of 0.3 kpc are derived.
Key words: galaxies: clusters: individual: M 81 group / galaxies: general / galaxies: photometry / galaxies: fundamental parameters
© European Southern Observatory (ESO), 2000