The Mid-Infrared Morphology of Normal Galaxies: ISOCAM images at 7 and 15 microns

Session 67 - ISM in Galaxies.
Display session, Wednesday, January 15
Metropolitan Ballroom,

[67.01] The Mid-Infrared Morphology of Normal Galaxies: ISOCAM images at 7 and 15 microns

N. A. Silbermann, G. Helou, C. A. Beichman (IPAC/Caltech), H. L. Dinerstein (U. Texas), D. J. Hollenbach (NASA/Ames), D. A. Hunter (Lowell Obs.), K. Y. Lo (U. Illinois), S. Lord (IPAC/Caltech), N. Lu (IPAC/Caltech), S. Malhotra (IPAC/Caltech), R. H. Rubin (NASA), G. Stacey (Cornell University), H. Thronson (Univ. of Wyoming), M. W. Werner (JPL)

We report on ISO-CAM observations and display images for about 20 galaxies at 7 and 15 \mum, with 7" resolution on a grid with 3" pixels. The images look similar at the two wavelengths, and generally similar to the visible light images from the POSS plates, though star forming regions are highlighted in the mid-IR. The calibration of ISO-CAM data is uncertain at the 20% level, so colors are comparable across the sample. There are significant variations in the 7-to-15 \mum colors: within galaxies, especially between central regions and disk emission, and from galaxy to galaxy. The global 7-to-15\mum colors in these galaxies are well correlated with their 60-to-100\mum colors. This is consistent with the interpertation that the 7\mum emission is dominated by PAHs, whereas the 15\mum emission is mostly due to hot dust, and the 7-to-15 \mum ratio reflects the mean heating intensity.

ISO (The Infrared Space Observatory) is an ESA mission with participation by NASA and ISAS. The CAM instrument was built by Cesarsky et al. (1996, Aamp;AL, Nov 10).

Program listing for Wednesday