Astronomy and Astrophysics Letters dedicated to ISO

ISOPHOT Maps of NGC6946 in the range 60 - 200 microns

R. J. Tuffs 1 - D. Lemke - C. Xu - J. I. Davies - C. Gabriel - I. Heinrichsen - G. Helou - H. Hippelein - N. Y. Lu - D. Skaley


We present maps of NGC6946 at 61 and 205 microns as well as scans through the galaxy at these and at 8 intermediate wavelengths. The bulk of the FIR luminosity arises from a diffuse disk component which extends beyond the 25 mag arcsec-2 B isophote to at least the radius corresponding to the sensitivity limit. A FIR emission counterpart to the outlying HI disk is seen at both 61 and 205 microns, for which a dust to HI mass ratio of 0.0046 is inferred from the 205 micron brightness assuming a dust temperature of 15K. The disk scale length at both 61 and 205 microns is similar to that seen in R-band.

galaxies - star formation - dust

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