hi high-velocity clouds (hvcs) have so far only be seen in the 21cm line of atomic hydrogen and as absorption features in optical spectra towards distant quasars. no firm estimates on their distances exist. therefore almost nothing is known about their chemical composition and physical parameters. despite several attempts no co has been found in hvcs. therefore the dominant cooling line for the clouds should be the 157.7micron cii fine structure line which we want to study towards an hi high-velocity cloud which is likely to interact with an intermediate velocity cloud. both clouds are positionally anticorrelated on the sky with almost no overlap between them. this unique positioning on the sky makes it possible to observe the cii line of the hvc without applying the time consuming fabry-perot mode of the lws which provides high frequency resolution. to get information on the interstellar radiation field of both clouds we want to observe two positions, one towards the ivc and one towards the hvc. the comparison of both positions will then give hints on the composition of the hvc and thus on its possible origin.
Instrument
LWS02
Temporal Coverage
1996-06-13T03:20:27Z/1996-06-13T04:58:17Z
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, HEITHAUSEN et al., 1999, 'IONIZED CARBON IN HIGH VELOCITY CLOUDS', 1.0, European Space Agency, https://doi.org/10.5270/esa-sco8eeq
