the study of linewidths of the molecular gas with a range in spatial- and density scales is important in understanding the dynamical inter- action between the center of star forming activity (in our case a fir source) and the surrounding gas, and as such provides essential infor- mation for star formation theory. measured linewidths are virtually always supra-thermal and supersonic; only observations in dense cores of lines that trace higher densities (like nh3, hc3n) sometimes show linewidths of the order of the thermal width. on the other hand, observations on a larger-scale of the surrounding gas (e.g. co) show lines dominated by non-thermal motions. the origins of these are still not completely understood, but they are in part due to the combined effects of stellar winds, outflows, and sn explosions stirring up the gas. typical co linewidths in regions of star formation are of the order of 3-5 km/s or more. this proposal concerns a molecular cloud with embedded massive star formation (iras23004+5642, or wb234 for short) where a strong and very narrow co line has been detected with iram (24 k, 1.02 km/s). the line has approximately sonic width, which is exceptional, especially because an h2o maser has been detected towards this source. this confirms the identification of wb234 as a star formation center, and makes this an intriguing object to study. iso allows us to penetrate the cloud in which the fir source is embedded, and to study its immediate surroundings (using lws, phot and cam). together with the intended ground-based observations this will provide us with a solid framework of data which should allow us to shed light on this remarkable object.
Instrument
CAM01 , LWS01 , PHT32
Temporal Coverage
1996-08-06T10:14:22Z/1997-03-03T09:03:37Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's 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, 1999, Narrow-Line Co Emission From A Molecular Cloud With Star Formation Sonic Linewidths From A Star-Forming Region, 1.0, European Space Agency, https://doi.org/10.5270/esa-cak1psd
