The transfer of resonance-line radiation in static astrophysical media
- D. Neufeld
- Physics
- 1 February 1990
An analytic solution is derived for the mean intensity of resonance-line radiation within an absorbing medium of large scattering optical depth but low density. The line profile, the mean number of…
The Escape of Lyman-Alpha Radiation from a Multiphase Interstellar Medium
- D. Neufeld
- Physics
- 1 April 1991
The Eddington approximation is used to model the transfer of radiation within a multiphase scattering medium. An estimate is thereby derived for the fraction of H Ly-alpha photons that escape from a…
Detection of the Water Reservoir in a Forming Planetary System
- M. Hogerheijde, E. Bergin, E. V. van Dishoeck
- Physics, GeologyScience
- 20 October 2011
The Heterodyne Instrument for the Far-Infrared on board the Herschel Space Observatory has detected emission lines from both spin isomers of cold water vapor from the disk around the young star TW Hydrae, hinting at a water ice reservoir equivalent to several thousand Earth oceans in mass.
Far-Infrared Water Emissions from Magnetohydrodynamic Shock Waves
- M. Kaufman, D. Neufeld
- Physics
- 10 January 1996
Nondissociative, magnetohydrodynamic, C-type shock waves are expected to be a prodigious source of far-infrared water emissions in dense interstellar regions. We have constructed a model to calculate…
Radiative Cooling of Warm Molecular Gas
- D. Neufeld, M. Kaufman
- Physics
- 20 November 1993
We consider the radiative cooling of warm (T >= 100 K), fully molecular astrophysical gas by rotational and vibrational transitions of the molecules H2O, CO, and H2. Using an escape probability…
The Abundance of Carbon Dioxide Ice in the Quiescent Intracloud Medium
- D. Whittet, S. Shenoy, D. Neufeld
- Physics, Environmental Science
- 20 January 2007
We present new observations with the Infrared Spectrograph on board the Spitzer Space Telescope of the solid-CO2 absorption feature near 15 μm in the spectra of eight field stars behind the Taurus…
The Mass Accretion Rate through the Masing Molecular Disk in the Active Galaxy NGC 4258
- D. Neufeld, P. Maloney
- Physics
- 1 July 1995
Recent observations (Miyoshi et al. 1995; Greenhill et al. 1995b) of water maser emission from the galaxy NGC 4258 have revealed the presence of a thin molecular disk of outer radius 0.25 pc which…
THE CHEMISTRY OF INTERSTELLAR MOLECULES CONTAINING THE HALOGEN ELEMENTS
- D. Neufeld, M. Wolfire
- Physics
- 10 October 2009
Although they are only minor constituents of the interstellar medium, halogen-containing molecules are of special interest because of their unique thermochemistry. Here, we present a theoretical…
The Chemistry of Fluorine-bearing Molecules in Diffuse and Dense Interstellar Gas Clouds
- D. Neufeld, M. Wolfire, P. Schilke
- Physics
- 13 April 2005
We present a theoretical investigation of the chemistry of fluorine-bearing molecules in diffuse and dense interstellar gas clouds, combining recent estimates for the rates of relevant chemical…
Spitzer Observations of HH 54 and HH 7-11: Mapping the H2 Ortho-to-Para Ratio in Shocked Molecular Gas
- D. Neufeld, G. Melnick, J. Pipher
- Physics
- 9 June 2006
We report the results of spectroscopic mapping observations carried out toward the Herbig-Haro objects HH 7-11 and HH 54 over the 5.2-37 μm region using the Infrared Spectrograph on the Spitzer Space…
...
...