the maximum emission of dust takes place at wavelengths longer than 100 microns if the temperature of the dust is lower than 35k. the dust inside dense clouds without internal heating sources never attains such a high temperature and its contribution to the emission in the iras bands therefore is usually small. the extension of wavelength coverage up to 200 microns by isophot is thus a major advantage over iras in sensitivity to very cold dust emission. the detection of the very cold dust in the cloud cores is among the main objectives in the isophot guaranteed time interstellar dust emission proposal where selected nearby dark clouds are mapped using isophot c100 and c200 at 90 and 200 microns, respectively. the spatial resolution and sensitivity of isophot are superior to iras. the iso mapping possibility allows the search for low luminosity point sources in nearby starforming sites thus expanding our knowledge of the faint end of the stellar luminosity function in these regions. as the luminosity function is time dependent objects in different phases of evolution are to be observed. we want to expand the wavelength coverage of the guaranteed time mappings of selected dark clouds to include also 60 and 135 microns. the contribution of different dust populations with different temperatures to the observed fir emission can now be studied using four wavelengths instead of two. this will make the interpretation of the data more reliable. the contribution of localized fir point sources can be taken into account because making a fully sampled sensitive 60 micron map will allow us to detect also the point sources which were too faint for iras. the detection of new, faint fir point sources in these clouds will provide us with significant new information on the faint end of the luminosity function.
Instrument
PHT22 , PHT37 , PHT38 , PHT39
Temporal Coverage
1996-08-03T22:53:43Z/1996-08-13T21:47:20Z
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, HAIKALA et al., 1999, 'MAPPING OF COLD DUST AND SEARCH FOR EMBEDDED YOUNG STARS', 1.0, European Space Agency, https://doi.org/10.5270/esa-8qgsgfm
