Arecibo Observations of IRAS Galaxies at 21 and 18 Centimeter Wavelengths
Abstract
Arecibo observations at 21 cm and 18 cm of a sample of galaxies selected for their intense far-infrared (FIR) emission are reported. The objective was to search for H I absorption and OH maser emission. No new cases were found. The significance of this null result is discussed both in terms of spatial distribution of the interstellar gas and dust and in terms of the continuum luminosity of the nucleus. Nevertheless, the H I profiles are extraordinary in that most are convex (single peak). This may suggest disruption of the disk rotation system in some cases. Little correlation is found between the hydrogen mass of these galaxies and their FIR luminosity. Comparison of these quantities suggests that the dust in these galaxies is under conditions very different from the solar neighborhood. Much more of the FIR emission apparently comes from H II regions than in normal galaxies. There is an excellent correlation between IR flux and radio continuum flux. The ratio of these two is the same as for normal spirals, which is surprising considering the many variables which could change this ratio.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1987
- DOI:
- 10.1086/165706
- Bibcode:
- 1987ApJ...322...88G
- Keywords:
-
- Astronomical Photometry;
- Centimeter Waves;
- Far Infrared Radiation;
- Galactic Structure;
- Infrared Spectra;
- Absorption Spectra;
- Hydrogen;
- Hydroxyl Emission;
- Infrared Astronomy Satellite;
- Interstellar Masers;
- Solar Neighborhood;
- Astrophysics;
- GALAXIES: PHOTOMETRY;
- INFRARED: SOURCES;
- RADIO SOURCES: GALAXIES;
- RADIO SOURCES: 21 CM RADIATION