we propose to study the environmental dependence of ir properties of spiral/irr galaxies by observing with iso (isocam, phot & lws) a complete sample (mp<15.7) of 20 late-type galaxies in the coma and a1367 clusters. these galaxies show evidence for ongoing dynamical interaction with the intracluster medium. they are selected for having 1) very blue color index (b-h<2.75) and/or 2) pronounced asymmetries in their radio (continuum and/or hi) and/or h alpha surface brightness distributions. these properties can be coherently interpreted in the framework of the drag model, i.e. assuming that these galaxies are currently entering the cluster environment, hence experiencing ram-pressure. the interaction is removing their hi gas on the up-stream side, or transforming it efficiently into h2, hence producing star bursts in supergiant hii regions. on the shocked up-stream interface the radio continuum emissivity is also enhanced, while on the down-stream side the magnetic field is stretched, forming long (>30 kpc) low brightness radio continuum trails. by observing these 20 galaxies with iso we hope determining: 1) the distribu- tion of the hot dust, hence indirectly of the young, massive stars (to be compared with the results of h alpha observations), and the spatial distribution of pahs heated by their radiation. 2) spectrophotometry with lws (158 micron) will ensure the deter- mination of the global cii line emission, which is expected to originate mainly from the massive star forming regions. 3) to check if the dynamical pressure has observable consequences on the dust distribution, spectrophotometric measurements in 6 bands (phot 60-200 micron) will provide the relative intensities of the various types of dust emitting at different temperatures. the cii and continuum measurements will be compared with similar measure- ments of isolated galaxies.
Instrument
CAM01 , PHT22
Temporal Coverage
1996-06-18T01:20:18Z/1997-07-25T01:27:55Z
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, Ir Properties Of S\/Irr Galaxies In The Coma And A1367 Clusters Late-Type Galaxies In Clusters, 1.0, European Space Agency, https://doi.org/10.5270/esa-uy6k27b
