Surface photometry of disk galaxies at 60 and 100 microns - Radial gradients in dust temperature in optically thin disks

Abstract

view Abstract Citations (30) References (42) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Surface Photometry of Disk Galaxies at 60 and 100 microns: Radial Gradients in Dust Temperature in Optically Thin Disks Bothun, Gregory D. ; Rogers, C. Abstract Surface, aperture, and grid photometry are performed at 60 and 100 microns for a sample of 28 nearby, large angular size galaxies. The spatial resolution of the data is 05-2.0 kpc, which allows for a coarse investigation of predicted radial gradients in physical dust temperature. We derive a model which predicts a drop of 3 K for every optical scale length, and this model agrees well with the data. In addition, for a subsample of 16 galaxies we directly compare the radial profile at 60 microns with that in the B or I band. Our model predicts that optically thick disks should have scale lengths a factor of 2 smaller at 60 microns compared to B. In the optically thin case, the scale lengths are about equal except for the effect of the gradient in dust temperature. Virtually all of the data support the prediction of the optically thin case. Finally, 10 galaxies in the sample have sufficient angular sizes to allow for a coarse 2D spatial mapping of the 60/100 micron flux ratio. These maps clearly reveal that, when present, small amounts of hot dust dominate the emission at 60 microns and effectively mask the existence of a much larger amount of cold dust. Publication: The Astronomical Journal Pub Date: May 1992 DOI: 10.1086/116162 Bibcode: 1992AJ....103.1484B Keywords: Astronomical Photometry; Cosmic Dust; Disk Galaxies; Galactic Structure; Astronomical Maps; Charge Coupled Devices; Color-Color Diagram; Infrared Astronomy Satellite; Optical Thickness; Astrophysics; GALAXIES: PHOTOMETRY; GALAXIES: INTERSTELLAR MATTER full text sources ADS | data products SIMBAD (29) NED (28)