IC 883 (Arp 193) appears as a highly inclined disk
with the reddening
increasing to the NW within the disk. The peak in the extinction-corrected
2.2 µm light distribution coincides with the 2.2
µm flux peak but
the centroid is clearly displaced to the northwest. The reddening
distribution shown above is similar to the CO(1-0)
emission which has a size 4.1" x 2.2" elongated along the
plane of the galaxy and with kinematic major axis in the same direction
(Bryant & Scoville 1999). (The increase in apparent 2.2/1.1
µm color ratio
on the NE of IC 883 is small and occuring at low flux flux levels; it
may be due
to flat-fielding errors.) A number a bright clusters are seen above and
below the
disk out to 5" radius. Their high luminosity suggests that they are
young (
Shaded contour plots of the extinction corrected
2.2 µm emission are shown together with the 1.1
µm (upper left)
observed emission. In both panels, the contours and shading are
logarithmic with the contours spaced by factors 21/2. (The level
values are the same as for the figure above). The arcsec displacements
in RA and DEC, given along the borders are measured from the 2.2
µm in
all frames. At the upper left, a length bar is drawn. For the ratio image,
both the 2.2 and 1.1 µm images were smoothed with the same adaptive
smoothing and then smoothed with a Gaussian FWHM = 0.2" in
calculating the 2.2 µm opacity from Eq. 3 (see text). In
cases where a
strong point-source or variable background contaminated the 2.2 µm
image, the extinction corrected image was derived for 1.6
µm. For the
galaxies with strong point-sources, the PSF was fit to the source and then
subtracted and replaced by a Gaussian with the proper integrated flux (see
text - NGC 7469, IRAS 08572+3915, IRAS 05189-2524, PKS 1345+12, IRAS 07598+6508, Mrk 1014 and 3C48).
109 yrs; see
below), implying that the galaxy may have
undergone a collision in the past with a burst of star and cluster
formation in spherical region before the ISM settled into its present
disk-like configuration. The near-infrared morphology of IC 883 is very
similar to that of M82 although the luminosity is scaled up by over an
order of magnitude.
