cometary globules are are the nicest examples illustrating the interaction of the uv photons from hot stars with dark clouds. they have bright rims associated to the ionization front which is dominating the dynamical evolution of the cloud and its potential to form stars (see the review by cernicharo, 1991). shock waves associated with the ionization front are expected to heat the medium, and to process the dust grains releasing complex molecules and refractory compounds to the gas phase. however, in the densest part of the globule the dust remains unchanged. the presence of dust in all possible states makes cometary globules the best laboratories to study the properties of the cosmic dust in general. we propose here a complete study of the dust properties by the means of ir observations of a carefully selected sample of globules of different types, and in different evolutionary states. additional measurements will be made of some spectral lines which are expected to play a crucial role in the thermal balance of the cloud (oi, cii, and ch). the unprecedent informations provided by these proposed observations, together with our on-going studies of the molecular content, and our detailed chemical and hydrodynamical modelling, will lead to a complete picture of such spectacular clouds, and will supply a full description of the physical and chemical properties of interstellar dust.
Instrument
CAM01 , CAM04 , LWS01 , PHT03 , PHT22
Temporal Coverage
1996-10-13T01:03:53Z/1997-03-17T22:00:50Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the worlds first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
European Space Agency, CERNICHARO et al., 1999, 'A STUDY OF DUST comma ATOMIC AND MOLECULAR EMISSION IN COMETARY GLOBULES THE PHYSICS OF PARTIALLY IONIZED GLOBULES', 1.0, European Space Agency, https://doi.org/10.5270/esa-idu9rmu
