Issue |
A&A
Volume 390, Number 3, August II 2002
|
|
---|---|---|
Page(s) | 829 - 861 | |
Section | Cosmology (including clusters of galaxies) | |
DOI | https://doi.org/10.1051/0004-6361:20011755 | |
Published online | 14 August 2002 |
The Westerbork HI survey of spiral and irregular galaxies
I. HI imaging of late-type dwarf galaxies
1
Kapteyn Astronomical Institute, PO Box 800, 9700 AV Groningen, The Netherlands
2
Dept. of Physics and Astronomy Johns Hopkins University, 3400 N. Charles Str., Baltimore, MD 21218, USA
3
Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
4
Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
Received:
3
August
2001
Accepted:
6
December
2001
Neutral hydrogen observations with the Westerbork Synthesis Radio
Telescope are presented for a sample of 73 late-type dwarf galaxies.
These observations are part of the WHISP project (Westerbork
Survey of Spiral and Irregular Galaxies). Here we present
maps, velocity fields, global profiles and radial surface density
profiles of
, as well as
masses,
radii and line widths.
For the late-type galaxies in our sample, we find that the ratio of
extent to optical diameter, defined as 6.4 disk scale lengths,
is on average 1.8 ± 0.8, similar to that seen in spiral galaxies.
Most of the dwarf galaxies in this sample are rich in
with a
typical
of 1.5. The relative
content
increases towards fainter absolute magnitudes
and towards fainter surface brightnesses. Dwarf galaxies with lower
average
column densities also have lower average optical
surface brightnesses. We find that lopsidedness is as common among
dwarf galaxies as it is in spiral galaxies. About half of the dwarf
galaxies in our sample have asymmetric global profiles, a third has
a lopsided
distribution, and about half shows signs of
kinematic lopsidedness.
Key words: surveys / galaxies: dwarf / galaxies: structure
© ESO, 2002
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.