===================================================================== ==> in this proposal, more time is being requested for tthuan.sbs_0335 ===================================================================== following our observation of sbs 0335-052 in the mid-infrared range we propose here to extend the infrared coverage of this exceptional object. this is motivated by the fact that sbs 0335-052, one of the most metal-deficient galaxy known, is much brighter in the infrared than expected from its star-forming properties (a factor of 6 in the lw10 band and we extrapolate at least a factor of 3 for the full infrared range). furthermore, the spectrum appears to require contribution from pah emission, i.e. carbon dust, a very unexpected dust component in a low metallicity object. the observations we propose to perform here are twofold: a cvf scan on the 9-16 microns that will: - assess the contribution of carbon based dust - reveal the shape of the continuum and allow comparison to that observed in more metal-rich objects - reveal the presence of a deep silicate absorption, an expected feature if the excess infrared is due to embedded hii regions. pht measurements at 25, 50, 60, 100, 120, 160 and 200 mic. the aim is to characterize with high details the infrared output of sbs in order to determine the origin of the excess emission, the amount of dust that is already present in the galaxy and the exact amount of star-formation generated energy that is released in the infrared. these observations would make of sbs 0335-052 one of the best studied analog to primordial galaxies that are now being detected at high redshift. the possibility that even very young galaxies might efficiently hide a substantial fraction of their star formation, as sbs 0335-052 appears to do, would have profound impacts on how we derive the star formation rate at high redshift.
Instrument
CAM04 , PHT03 , PHT22
Temporal Coverage
1998-03-09T19:49:57Z/1998-03-09T23:56:42Z
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, THUAN et al., 1999, 'DUST AND INFRARED EMISSION IN THE EXTREMELY METAL-DEFICIENT', 1.0, European Space Agency, https://doi.org/10.5270/esa-l4c6l48
