we still do not know if pahs (or other carbon dominated elements) exist in environments as deficient in metal as in the case of the smc. from the ultraviolet observations, the smc mean extinction curve shows a very weak bump at 0.22 microns compared to the galactic curve. the lmc curve is intermediate between the smc and milky way curves. this observational fact is thought to be related to the underabundance of carbon in the interstellar dust in these irregular galaxies compared to the solar neighborhood. from the iras observations on the smc one observes a very weak mid-infrared (12 and 25 microns) emission. there seems to be a tight correlation between the ratio nu*i(12 microns) to far-infrared and the abundance o/h, which suggests that the weakness of the 12 microns emission is due to a metallicity effect. the search of the pah features in the magellanic clouds will permit a more quantitative analysis in the frame of models accounting for the underabundance of carbon in the dust grain population. the principal goals of this proposal are: 1) the detection of the near infrared features at 7.7 and 11.3 microns. 2) a sensitive photometry over a broad range of wavelengths to constrain the models of grain population (composition and size distribution). 3) measuring occasional contribution of line emissions in the far infrared. 4) comparison between the far infrared emission and hi distribution.
Instrument
CAM01 , PHT03 , PHT22
Temporal Coverage
1996-05-25T05:36:15Z/1998-03-15T00:54:11Z
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, Diffuse Interstellar Medium In The Magellanic Clouds Are There Pahs In The Magellanic Cloudsquestionmark, 1.0, European Space Agency, https://doi.org/10.5270/esa-c8s3lfm
