Astronomy and Astrophysics – Astronomy
Scientific paper
Nov 1993
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993apj...418..113p&link_type=abstract
Astrophysical Journal v.418, p.113
Astronomy and Astrophysics
Astronomy
66
Galaxies: Cooling Flows, Galaxies: Individual Ngc Number: Ngc 4254, Galaxies: Spiral, Galaxies: Structure, Radio Lines: Galaxies
Scientific paper
We present high-resolution H I and Hα observations of the spiral galaxy NGC 4254. The observations were obtained with the VLA and the Maryland-Caltech Fabry-Perot camera, respectively. NGC 4254 is unusual in having a grand-design spiral structure with a strong m = 1 component for which there is no obvious cause in optical images. Our observations reveal that, in addition to the usual galactic disk component, there are H I clouds superposed on and beyond the H I disk, at velocities up to 150 km s^-1^ from those established for the disk. The mass in these clouds is ~2.3 x 10^8^ M_sun_, and they may be the remnants of an entity that was tidally disrupted by NGC 4254 and is now merging with it. The direct effects of the interaction between the cloud gas and the galaxy are limited to the region where the gas appears to be merging with the disk, where it may be causing a warp. But the indirect effects of the infalling gas appear profound: it is the most likely cause for the unusual spiral structure of NGC 4254. If so, the m = 1 spiral structure of NGC 4254 is recent, and an internal amplification mechanism such as swing amplification has played a major role in its evolution. Since NGC 4254 does not appear to be exceptionally deficient in dark matter and is apparently a normal Sc galaxy, the nature of the interaction appears important in determining the susceptibility of the disk to various spiral modes (in particular the m = 1,3, and 5 modes of NGC 4254).
Mundy Lee G.
Phookun Bikram
Vogel Stuart N.
No associations
LandOfFree
NGC 4254: A Spiral Galaxy with an M = 1 Mode and Infalling Gas does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with NGC 4254: A Spiral Galaxy with an M = 1 Mode and Infalling Gas, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and NGC 4254: A Spiral Galaxy with an M = 1 Mode and Infalling Gas will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-808790