3C 318.1, very steep radio spectrum.
3C 318.1 (NGC 5920). - The outer halo and surrounding field of this
elliptical galaxy are pockmarked with several faint point sources and
nebulous, low-surface brightness emission regions, all within a radius
of ~ 15" (14 kpc) from the center of the galaxy. Two small elliptical
galaxies lie 15" (14 kpc) and 17" (16 kpc) to the southeast and
northwest, respectively. At roughly 0.5 kpc northeast of the nucleus,
the isophotes become jagged, a possible signature of an obscuring dust
lane, which would be more clearly revealed in a deeper exposure. In
fact, the isophotes slowly rotate from a rough north-south orientation
in the core to a more east-west direction in the outer halo.
3C 318.1.--The optical HST image of this galaxy reveals a rather normal looking
elliptical galaxy whose inner contours are relatively rounder than the other
ones. The F702W image is comparable in space to that of 3C 317. No clear
isophotal twists or disks are visible. In the F220W filter no UV flux was
detected even after 1200 s integration. Extended UV emission is seen in the
F320W and the F372M images. The UV contours are relatively round (i.e., like
the inner regions of the optical image), and there is no nuclear contribution
to the flux. In fact, it appears that the innermost regions of the galaxy
suffer from internal extinction, which is seen clearly in the surface
brightness profiles. Since the UV image of galaxy is round, the regions outside
0.3" were fitted by the r^1.4^ law (the fit is actually relatively good and
much better than for most galaxies in our sample), and a model profile was
produced. From these model profiles, we determine that the nuclear extinction
in F320W is ~0.57 and in F372M is ~0.52 mag. The errors in these values are
+/-0.20 mag and depend on the model parameters that are used.
= 3C 318.1
= 4C 07.41
= UGC 09822
In a group.
Ap. J., 183, 711, 731, 1973.
Ap. J., 183, 711, 1973.
M.N.R.A.S. 168, 307, 1974.
M.N.R.A.S., 168, 307, 1974.
Brightest in group of about 10 galaxies in CGCG cluster 15 18.8 +07 47,
medium compact, medium distant
15 19.2 +07 54 at 2.7, 289, 0.15 x 0.15, very compact, m=15.7