Issue |
Astron. Astrophys. Suppl. Ser.
Volume 139, Number 1, October I 1999
|
|
---|---|---|
Page(s) | 97 - 103 | |
DOI | https://doi.org/10.1051/aas:1999383 | |
Published online | 15 October 1999 |
HI properties of nearby galaxies from a volume-limited sample*
1
Special Astrophysical Observatory, Russian Academy of Sciences, N.Arkhyz, KChR, 357147, Russia
2
Max-Planck-Institut für Radioastronomie, Auf dem Hugel 69, D-53121 Bonn, Germany
Send offprint request to: W.K. Huchtmeier
Received:
25
May
1999
Accepted:
1
July
1999
We consider global HI and optical properties of about three hundred
nearby galaxies with 500 km s-1. The majority of them have individual
photometric distance estimates. The galaxy sample parameters show some
known and some new correlations implying a meaningful dynamic explanation:
1) In the whole range of diameters,
Kpc, the galaxy standard
diameter and rotational velocity follows
a nearly linear Tully-Fisher
relation,
2)
The HI mass-to-luminosity
ratio and the HI mass-to-"total" mass (inside the standard optical diameter)
ratio increase systematically from giant
galaxies towards dwarfs, reaching maximum values
and 3,
respectively. 3) For all the Local Volume galaxies their total
mass-to-luminosity ratio lies within a range of [0.2–16]
with a median
of
. The
ratio decreases slightly from giant
towards dwarf galaxies. 4) The
and
ratios for the
sample galaxies correlate with their mean optical surface brightness,
which may be caused by star formation activity in the galaxies.
5) The
and
ratios are practically independent of the local
mass density of surrounding galaxies within the range of densities of about
six orders of magnitude. 6) For the LV galaxies their HI mass and angular momentum
follow a nearly linear relation:
,
expected for rotating gaseous disks being near the threshold of gravitational
instability, favourable for active star formation.
Key words: galaxies: global HI parameters / galaxies
© European Southern Observatory (ESO), 1999