Using far-infrared limb brightening to probe isolated dark globules

Abstract

view Abstract Citations (17) References (36) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Using Far-Infrared Limb Brightening to Probe Isolated Dark Globules Leung, Chun Ming ; O'Brien, Estela V. ; Dubisch, Russell Abstract The problem of radiation transport in dark globules with or without internal heat source, immersed in an isotropic incident interstellar radiation field, is solved. The phenomenon of infrared limb brightening, its dependence on cloud properties, and its observational implications are addressed. Numerical results regarding the dependence of limb brightening on total cloud opacity, luminosity of internal heat source, grain type, dust density distribution, and wavelength of emitted radiation are discussed. Observational implications concerning the use of limb brightening to place an upper limit on the luminosity of an embedded protostar and to determine the grain emissivity law in the far-infrared are examined. For sufficiently large optical depth, the limb-brightening ratio (LBR) is found to be related to the optical depth by a power-law relation in the 140-300 micron wavelength range, where thermal emission from grains peaks. By observing the LBR in this range, this power-law relationship can be exploited to determine the emissivity law of the dust grain in the far-infrared. Both the LBR and the longest wavelength for which limb brightening still occurs are related linearly to the luminosity of the central source. Publication: The Astrophysical Journal Pub Date: February 1989 DOI: 10.1086/167103 Bibcode: 1989ApJ...337..293L Keywords: Far Infrared Radiation; Infrared Sources (Astronomy); Interstellar Matter; Limb Brightening; Nebulae; Infrared Astronomy Satellite; Infrared Spectra; Optical Thickness; Astrophysics; INFRARED: SPECTRA; INTERSTELLAR: GRAINS; NEBULAE: GENERAL full text sources ADS | data products SIMBAD (4)