Meter-Wavelength Observations of Galactic Radio Sources and the Radiation from the Galactic Disk
1972; IOP Publishing; Volume: 174; Linguagem: Inglês
10.1086/151466
ISSN1538-4357
Autores Tópico(s)Astronomy and Astrophysical Research
Resumoview Abstract Citations (22) References (18) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Meter-Wavelength Observations of Galactic Radio Sources and the Radiation from the Galactic Disk Parrish, Alan Abstract The 1000-foot-diameter (305 m) radio telescope at the Arecibo Observatory has been used to observe the continuum emission of galactic sources at low radio frequencies. The following sources were observed: W49, W51, W56, NGC 1499, IC 410, NGC 2175, and NGC 2244. Observations were made at seven frequencies: 53, 65, 74, 89, 111, 196, and 318 MHz. Arrangements were made to obtain data on several of these frequencies simultaneously. densities of the observed sources are presented at the low frequencies. The data are also analyzed to obtain an estimate of the electron temperature of each thermal source, as well as the brightness tempera kure level of the nonthermal radiation in the line of sight to and beyond each source. The analysis procedu? using models of the sources to generate theoretical spectra for various values of two free par4meters: the electron temperature and the background brightness-temperature level. In performing the;analysis, convolution techniques were used to equalize the effects of different amounts of beam smoothing at different frequencies. Such techniques were especially helpful in analyzing data containing con tri\\ from nearby confusing sources. The derived electron-temperature results are sufficiently accurate to be compared with the results of recdtnbinatinn-line observations of NGC 2244. A range of pairs of permissible electron temperatures and background brightness-temperature levels is obtained for each of the other sources. Given this data, independent knowledge of the electron temperature of a source determines its associated background brightness-temperature level, and the latter result may be used in estimating the spatial distribution of the galactic non thermal radiation. Publication: The Astrophysical Journal Pub Date: May 1972 DOI: 10.1086/151466 Bibcode: 1972ApJ...174...33P full text sources ADS |
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