view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A radio model of the galaxy. Wyatt, Stanley P., Jr. Abstract An analysis is carried out to determine the structure of the galaxy as it is defined by the intensity distribution of continuous radio emlssion at 100 mc/sec. Observational data are the radio isophotes of Bolton and Westfold. Results depend on the likely assumptions that the radio galaxy is axially symmetric and that it is transparent at 100 mc/sec. The density function in the galactic plane turns out to be approximately Gaussian in character, with a fairly "flat" nucleus, the sharpest decay in the regions 2-4 kiloparsecs from the center, and a nearly linear decrease in the vicinity of the sun. The curve agrees with that found by Bolton and Westfold for the inner part of the galaxy. The density of radio sources in the galactic core is 5.4 + 1.2 (p.e.) times the local density near the sun; and the average emission in our part of the Milky Way system is 1.1 X I0-~~ erg cm~3 sec-1 (c/sec)-1. Superposed on the smooth radio galaxy are two additional features: first, a constant component with brightness temperature about 45o0K, to be identified with the spherically distributed excess radiation discovered by Westerhout and Oort; second, an asymmetric component in the anti-center directions, probably originating from HIl clouds in the Morgan-Osterbrock-Sharpless spiral arm that passes three hundred parsecs exterior to the sun. The density distribution in the z-direction is assumed, as a first approximation, to follow a Gaussian law. In the nuclear part of the galaxy, the decay-rate at right angles to the galactic plane is about five times as rapid as in the plane. In the solar neighborhood, the decay ratio is only three. An unknown fraction of the 4500 spherical excess is extragalactic in origin. The calculated temperature due to other galaxies radiating more or less like our own is found to be small compared with this value. A brief discussion centers on several extragalactic effects that may contribute to an increase of the calculated temperature. University of Michigan Observatory, Ann Arbor, Mich. Publication: The Astronomical Journal Pub Date: 1952 DOI: 10.1086/106667 Bibcode: 1952AJ.....57R.168W full text sources ADS |