Accession Number : AD0754120

Title :   A Search for Lambda 21 cm Absorption in QSS and Other Sources near to Spiral Galaxies,

Corporate Author : OWENS VALLEY RADIO OBSERVATORY PASADENA CALIF

Personal Author(s) : Wright,M. C. H. ; Gottesman,S. T.

Report Date : 1972

Pagination or Media Count : 14

Abstract : Observations are described which attempt to detect lambda 21 cm absorption in the spectra of 3C275.1, 3C232, 3C13 and 4C29.03 which are within 2 Holmberg radii of Sc and Sb type galaxies. None was found to a limiting r.m.s. absorption of 1, 2, 1.5 and 2.5% respectively in a 21 km/s bandwidth. The regions around these sources have also been observed for lambda 21 cm emission. No line emission has been detected in the regions around 3C232 and 3C13, but emission detected from the Sc galaxy NGC4651 gives an average HI surface density of 5.5 x 10 to the 20th power/sq cm for the region including 3C275.1. Adopting a model for the neutral HI distribution leads to a gas kinetic temperature that may be in excess of 18K. (Author)

Descriptors :   (*EXTRATERRESTRIAL RADIO WAVES, HYDROGEN), DETECTION, INTERSTELLAR MATTER, ABSORPTION

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE