Heating of H II regions with application to the Galactic center

Abstract

view Abstract Citations (7) References (51) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Heating of H II Regions with Application to the Galactic Center Maloney, Philip R. ; Hollenbach, David J. ; Townes, Charles H. Abstract The heating and thermal equilibrium of photoionized gas is reviewed. Photon-heating mechanisms (UV photoionization heating, grain photoelectric heating, and X-ray heating) either fail to provide the required heating rates or else require that the ionization state of the gas is very high. Specific application to the Galactic center observations show that the total heating power required to maintain the gas at the derived temperatures, using the observed emission measure in the bar and the temperature distribution derived from the radio recombination lines, is about 7 x 10 exp 6 solar luminosities, comparable to the bolometric luminosity of the central source as measured by the FIR flux from grains. Thus, the cooling emission from this hot gas, if LTE-derived temperatures are correct, would supply a major fraction of the bolometric and ionizing luminosity inferred from the ionized gas in the central 1 pc cavity and the dust and neutral gas in the surrounding torus. Publication: The Astrophysical Journal Pub Date: December 1992 DOI: 10.1086/172086 Bibcode: 1992ApJ...401..559M Keywords: Galactic Nuclei; H Ii Regions; Interstellar Gas; Radiative Transfer; Temperature Distribution; Continuous Spectra; Local Thermodynamic Equilibrium; Sagittarius Constellation; Shock Waves; Very Large Array (Vla); Astrophysics; GALAXY: CENTER; GALAXIES: INTERSTELLAR MATTER; RADIATIVE TRANSFER; RADIO LINES: ATOMIC full text sources ADS | data products SIMBAD (3)