The Meaning of the OH-H_{2};O Maser Maps

Abstract

view Abstract Citations (48) References (24) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Meaning of the OH-H_{2};O Maser Maps Litvak, M. M. Abstract The approximate conditions of density, diameter, and temperature of the OH and H2O maser regions are deduced from the very long baseline interferometry, from the presence of microwave saturation from the energy requirements, from the absence of excessive pressure or thermal broadening, from the microwave optical depths, and from the selection of hyperfine components. The amplifier surrounding each emission point has a diameter comparable to the distance between neighboring points and a mass close to 1 M0. Calculations indicate that the nonlinear effect of self-focusing is probably not occurring, that stimulated Raman scattering is yielding only the lowest hyperfine component in H2O with a lineshape asymmetry toward lower frequency, and that for both OH and 1120 the interferometers are observing "hot spots" of unsaturated amplification. Ordinary scattering from spatial fluctuations in electron density probably accounts for the observed angular sizes, especially for 18-cm OH signals. The region appears to consist of condensations each of about 1 Al0 on the edges of two parallel, slowly corotating disks each about 100 Alo. A stable, large-scale rotational discontinuity (of velocity and magnetic field) may be propagating between the two disks. Publication: The Astrophysical Journal Pub Date: November 1971 DOI: 10.1086/151189 Bibcode: 1971ApJ...170...71L full text sources ADS |