= > in this proposal, more time is being requested for fcasoli.isol_16 > time for this proposal is to be transferred from fcasoli.isol_16 = the environment exerts a major influence on spiral galaxies, their star formation activity and the nature and composition of their interstellar medium. iso will provide a major progress in this field with the studies of the virgo and coma clusters. but to draw quantitative estimates of these environmental effects, it is mandatory to construct a reference sample of isolated galaxies. a reference sample will also be useful to compare with galaxies in small groups or at cosmological distances. it is this reference sample that we have proposed to build in our previous proposal (star formation and gas content in isolated galaxies:a reference sample). the goal was to observe with the lws the cii line at 158 microns in a large sample of isolated galaxies.this line is the main coolant of the ism, and probes both the photon-dominated regions associated with massive-star formation and the diffuse atomic phase. it is widely used as a star-formation tracer but its exact relationship with the star-formation regions is still not well understood. we will also get the continuum spectrum of the targets between 100 and 200 microns, which will allow us to estimate their cool dust and gas content. in addition to the data at other wavelengths, the proposed observations will allow us to estimate the dust and gas contents of isolated galaxies, their global star formation activity, the relative contributions of the molecular and atomic phases in the formation of the cii line, and to study the effect of the environment on all these properties. our original sample was of 120 galaxies. using the in-flight sensitivities, we had to reduce the sample to 67 g...alaxies, and out of 3 observed galaxies only one is detected. thus we propose to increase the observing time on the 35 best-known objects.
Instrument
LWS02
Temporal Coverage
1998-02-22T09:22:34Z/1998-02-22T09:32:06Z
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.
