Computer Science – Numerical Analysis
Scientific paper
Mar 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994aj....107..971t&link_type=abstract
Astronomical Journal (ISSN 0004-6256), vol. 107, no. 3, p. 971-983
Computer Science
Numerical Analysis
104
Density Distribution, Dwarf Galaxies, Position (Location), Star Formation, Velocity Distribution, Astronomical Observatories, Cameras, Charge Coupled Devices, Data Reduction, Numerical Analysis, Optical Filters, Spatial Resolution, Telescopes, Very Large Array (Vla)
Scientific paper
We present high resolution Very Large Array (VLA) 21 cm line observations of five H II galaxies combined with previous lower resolution data from Taylor et al. (1993) and optical broadband R and H-alpha Charge Coupled Device (CCD) images of the systems. Following Kennicutt (1989) we calculated the threshold H I surface density for star formation for the H II galaxies and compared the location and shape of this predicted threshold density contour with the optical shape of the galaxies. We find generally a good correlation between these two, although a constant density contour of 1021/sq cm fits the images of the optical galaxies equally as well. The H I synthesis observations have revealed that the H II galaxies have sharply peaked H I radial profiles, in contrast to the relatively flattened profiles of low surface brightness (LSB) galaxies, suggesting that large central concentrations of gas are a necessary condition for the occurrence of bursts of massive star formation seen in H II galaxies. These observations are consistent with the hypothesis that LSB galaxies represent the quiescent phase of H II galaxies, if a suitable mechanism exists (such as galaxy interactions) to cause H I to concentrate at the center of LSB galaxies prior to the onset of the burst of star formation. However, it is noted that the H II galaxies (and dwarf galaxies in general) span a relatively large range in mass. Since many properties correlate with mass (e.g., gas mass fraction), we point out that great care needs to be taken in choosing the proper comparison samples of LSB and H II galaxies.
Brinks Elias
Pogge Richard W.
Skillman Evan D.
Taylor Christopher Lee
No associations
LandOfFree
Star formation thresholds in H II galaxies with H I companions 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 Star formation thresholds in H II galaxies with H I companions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Star formation thresholds in H II galaxies with H I companions will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1870268