IRAS detection of very cold dust in the LYNDS 134 cloud complex

Abstract

view Abstract Citations (93) References (45) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS IRAS Detection of Very Cold Dust in the Lynds 134 Cloud Complex Laureijs, R. J. ; Clark, F. O. ; Prusti, T. Abstract IRAS maps at 60 and 100 microns of the complex of dark clouds containing L1345, L183, and L1780 are presented and discussed. Extended regions are apparent where the 60 micron emission is very low compared to the 100 micron emission. The 60-100 micron flux ratio has a constant value of 0.2 in the outer diffuse parts of the clouds but suddenly drops to less than 0.03 in the opaque cloud centers. A geometrical model is used to show that the drop occurs in a narrow transition layer that has not been resolved by IRAS. The observations provide direct evidence for dust temperatures colder than 15 K in dark clouds. A number of 60 micron-deficient regions are defined using the quantity Delta I(100) = I(60)/Theta, where Theta is the ratio I(60)/I(100) in the diffuse parts of the complex. Delta I(100) is highly proportional to extinction and (C-13)O column density. The relationships indicate that the dust temperature must be constant over a large fraction of the volume sampled by Delta I(100). An upper limit of 4.8 g/sq cm is obtained for the mass absorption coefficient of dust at 100 microns. Publication: The Astrophysical Journal Pub Date: May 1991 DOI: 10.1086/169963 Bibcode: 1991ApJ...372..185L Keywords: Cosmic Dust; Dark Matter; Infrared Sources (Astronomy); Molecular Clouds; Emission Spectra; Infrared Astronomy Satellite; Interstellar Matter; Nebulae; Astronomy; INFRARED: SOURCES; INTERSTELLAR: GRAINS; NEBULAE: INDIVIDUAL ALPHANUMERIC: L134 (LYNDS 134) full text sources ADS | data products SIMBAD (3)