Virgo Cluster Galaxies: Neutral Hydrogen Studies.
Abstract
Line radiation at 21 cm wavelength from neutral hydrogen (HI) in 17 galaxies in or near the Virgo cluster of galaxies was observed and mapped using the Arecibo radio-telescope. A calibration of the radio-telescope, and new gain corrections as a function of zenith angle are described. Velocity measurements, HI content and extent, and galaxy "spin" determinations are given, and an IG map is shown for each galaxy. An analytic investigation of detailed HI profile shapes leads to a method for recovering HI surface density curves from Arecibo profiles. The method is applied to 7 galaxies, in their middle section, the HI surface density curves resemble power laws with indices from -1 to -2.5. The method works best for edge-on galaxies with large rotation velocities.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1980
- Bibcode:
- 1980PhDT.........8H
- Keywords:
-
- Physics: Astronomy and Astrophysics;
- Disk Galaxies;
- Hydrogen;
- Neutral Gases;
- Stellar Radiation;
- Galaxies;
- Stellar Luminosity;
- Astrophysics