the galactic center region provides a unique opportunity to determine the near- and mid-infrared extinction law, because bright sources are located behind a fairly uniform foreground screen extinction, thus avoding complications arising in situations of mixed emission/extinction as commonly found in star forming regions. from iso-sws observations of h recombination lines towards sgra* we have found that the extinction law lacks the deep minimum in the 4-7um region that is expected for standard graphite/silicate mixes (see fig.1). we propose to determine in more detail this unexpected shape of the extinction curve, and to check whether it applies to other lines of sight close to the center of our galaxy. our observations will use as probes recombination lines of atomic hydrogen and groups of molecular hydrogen lines sharing a common upper level.
Instrument
SWS02 , SWS06 , SWS07
Temporal Coverage
1997-02-21T20:56:25Z/1997-03-27T17:30:39Z
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, LUTZ et al., 1999, 'THE MID-INFRARED EXTINCTION LAW TOWARDS THE GALACTIC CENTER', 1.0, European Space Agency, https://doi.org/10.5270/esa-u05ie73
