low surface brightness (lsb) galaxies have central surface brightnesses in the b which are up to five magnitudes/sq. asec. fainter than those of 'normal. high surface brightness (hsb) galaxies (typically b(0) 21.65 mag/sq. asec.). nevertheless, they have relatively normal integrated luminosity and high mass to light (m/l) ratios because they are rich in h1 relative to their low surface brightnesses. in fact they have more-or-less normal total masses. they occur in all hubble types but are anomalously blue. some lsbs (e.g. large lsb spirals similar to malin i) may harbour agns. historically, selection effects have tended to discriminate against the inclusion of lsbgs in galaxy catalogues, yet they may in fact constitute a significant component of the overall galaxy population. they seem to occur in regions of lower galaxy density in which they may evolve slowly and quiescently over a hubble time, without being disturbed by intractions with other systems. they constitute a population of objects which is novel and distinct from the historically familiar galaxy population and yet at the same time entirely significant to the understanding of galaxy formation and evolution in general. they present a wholely unfamiliar context for star formation, which they support almost completely in a h1 medium devoid of molecular gas. we propose to extend coverage of these systems into the fir (out to 160 microns) using isophot. this will greatly extend the information that is available concerning the physical conditions and environment which govern the highly anomalous star formation occurring in these systems. in so doing, we will not just fill a gap in the coverage of normal galaxy types with iso, but rather will extend the iso coverage into a new domain of galaxy properties.
Instrument
PHT22
Temporal Coverage
1996-11-25T00:48:44Z/1998-01-31T23:22:38Z
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.
