Issue |
Astron. Astrophys. Suppl. Ser.
Volume 141, Number 1, January I 2000
|
|
---|---|---|
Page(s) | 103 - 111 | |
DOI | https://doi.org/10.1051/aas:2000313 | |
Published online | 15 January 2000 |
BVRI imaging of M 51-type pairs *
II. Bulge and disk parameters
Department of Astronomy, University of Oulu, PL 333 90571 Oulu, Finland e-mail: eija@koivu.oulu.fi
Send offprint request to: E. Laurikainen
Received:
2
September
1999
Accepted:
8
October
1999
We present decompositions of azimuthally averaged surface
brightness profiles in
optical B, V, R and I-bands for a sample of 40 M 51-type
interacting galaxies. The profiles were modelled by an exponential
disk and a spherical bulge described either by the law or
by an
exponential function. Half of the galaxies were well fitted by
both bulge models, whereas for
the exponential
function was a better choice. Special care was taken on
eliminating superpositions of the companion galaxies. The mean
B-band central surface brightness
was found to be
, which is near to the value originally
found by Freeman (1970), but the scatter was
fairly large. Galaxy interactions
have strongly modified the disks in many of the galaxies in the
sample. For example, six of them had extremely flat brightness profiles outside
the exponential part of the disk, and many showed
significant isophotal twists.
Key words: galaxies / interactions / photometry / fundamental parameters
© European Southern Observatory (ESO), 2000