it is proposed to observe three maps towards a high-latitude cirrus cloud using the pht 60, 120, and 200micron bands. from the iras observations a varying i60/i100 ratio is obvious indicating a decreasing dust temperature towards the inner parts of the cloud. to quantify this finding, three fields are proposed for iso observations: a first field will map the bright rim of the cloud and its associated formaldehyde core. it is oriented towards the illuminating galactic plane and should show the steepest temperature gradient from the rim to the dense core. the remaining two fields are centred on the long dust filaments attached to the cloud, one of them again towards the galactic plane, the other one towards the north, and therefore expected to be colder. the observations will help to model the dust temperature and therefore the radiation field for important parts of the cloud. the radiation field is a crucial parameter when modelling the chemistry because it determines the photophysics of molecules observed in this cloud.
Instrument
PHT32
Temporal Coverage
1996-03-03T02:52:39Z/1996-03-03T06:00:39Z
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, Cold Dust And Dust Filaments In A High-Latitude Cirrus Cloud, 1.0, European Space Agency, https://doi.org/10.5270/esa-mx08rr3
