Accession Number : AD0773573

Title :   A Study of the HI Absorption in the Galaxy M82 by Radio Interferometry,


Personal Author(s) : Weliachew,L.

Report Date : 1973

Pagination or Media Count : 25

Abstract : The continuum source located in the IrrII galaxy M82 has been studied in HI absorption at 21 cm wavelength. Absorption by gas located in M82 has been detected and mapped with an east-west interferometer. The maximum baseline length was approximately 4500 lambda. The velocity resolution was 21 km/sec. The positions of fifteen velocity centroids of the HI absorption have been determined to within 1-3 arc sec accuracy relative to one another. This allows direct comparison with a recent optical study (Heckathorn 1972). For the first time agreement is found between the systemic velocities of M82 determined by optical and radio methods. Several features of the velocity field are discussed particularly in the framework of the dust-scattering models recently proposed for M82. (Modified author abstract)

Descriptors :   *Galaxies, *Extraterrestrial radio waves, Radio astronomy, Hydrogen, Absorption spectra

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE