iras data have been able to demonstrate the presence of dust in the icm (inter cluster medium) connected with a few dominant galaxies centered in cooling flows of x-ray emitting gas. the grains are predominantly heated by the bombardment of fast electrons. the fir-emission from the grains therefore becomes a sensitive probe of the temperature and density of the hot gas. because the grains are destroyed by sputtering on a short time scale (about 10e7 yr), the mere presence of dust calls for an explanation. in some cases (ngc4696) dust may have been accreted from outside, but in other cases (hydra a) this seems unlikely. for hydra a we have shown that mass-loss from evolved stars produces an insufficient amount of dust to explain the fir luminosity. instead we argue, that dust is produced in connection with star formation in the flow. the detection of fir emission from dust in the icm will provide important constraints for cooling flow models. dedicated iso observations of a sample of cooling flows will (1) learn us about the abundance of dust, (2) give some insight into grain properties (temperatures/sizes) in hot gas, (3) give information on densities and temperatures of the hot gas, (4) test our hypothesis of dust production in cooling flows, (5) maybe supply indirect evidence for low-mass star formation, and (6) show if fir-emission from dust is a major coolant in cooling flows. *** please notice printed addendum to visitors report ***
Instrument
PHT32
Temporal Coverage
1996-05-07T23:36:52Z/1996-11-21T15:18:14Z
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, HANSEN et al., 1999, 'DUST IN COOLING FLOWS PRODUCTION AND DESTRUCTION OF DUST IN X-RAY GAS ENVIRONMENTS', 1.0, European Space Agency, https://doi.org/10.5270/esa-r9a4rri
