A Wide Field Survey for Low Surface Brightness Galaxies:
I. Data Aquisition, Description and Initial Results
Authors: Karen O'Neil, G. D. Bothun, & Mark E. Cornell
Published:The Astronomical Journal, Vol. 113, pg 1212 (1997).
ABSTRACT:
A Low Surface Brightness (LSB) galaxy survey of the Cancer and Pegasus
galaxy clusters and the low density regime defined by the Great
Wall, was undertaken between 14 October 1993 and 17 April 1996
using the University of Texas MacDonald Observatory 0.8m telescope and
a LF1 2048x2048 CCD camera. 127 galaxies were found with µ(0)> 22.0
B mag/arcsec², 119 of which are previously unidentified. Structural
parameters (µ(0), alpha, r25, etc) and colors
(Johnson/Cousins U,B,V,I, & R, when possible) were determined for the
galaxies. The majority of these galaxies
(80%) were well fit by an exponential profile, while the
remaining were either fit by a king profile (17%) or were too clumpy
to be fit by any curve (3%). None of the galaxies were fit by a
de Vaucouleurs (1959) r¼-type profile.
The average central surface brightness
of the sample is 23.06±0.20 B mag/arcsec². The
central surface brightness distribution
of the galaxies is flat from 22.0 µ(0) B mag/arcsec² µ(0) to
24.0 B mag/arcsec² µ(0), at which point a
sharp drop-off is observed. By eliminating the possibility the
drop-off is due to selection or distance effects, we show that it is
highly likely the drop-off is due
to the inability for extremely LSB galaxies to form in the cluster
environment. Finally, previous data has shown that LSBs are deficient in
molecular gas and dust. If we assume that LSBs have no dust and correct
the sample to face-on surface brightness, the lowest surface brightness
disk we detected has µ(0) = 27.1 B mag/arcsec². However,
this sample shows the same
non-correlation between inclination and central surface brightness that
is seen for the case of high surface brightness galaxies. This non-correlation
has been used as an argument to support the notion that disk
galaxies are optically thick. Since its extremely unlikely that LSBs
are optically thick (i.e. none are IRAS sources) this non-correlation most
likely reflects the large intrinsic range of disk galaxy surface brightness
instead of variations in disk galaxy opacity.
Paper.ps (gzipped) (5426 kb)
table2.ps (42 kb)
table3.ps (42 kb)