A5. 3C 123 - The Galactic column density used for this source is taken from the
earlier analysis of the Chandra data by Hardcastle, Birkinshaw & Worrall (2001)
and the dominant (absorbed) power-law model has similar parameters to the one
fitted there. The large amount of Galactic reddening (the source is known to lie
behind a molecular cloud) makes its classification as a low-excitation object
uncertain. Chiaberge et al. (2002) show that its position on their diagnostic
plane (equivalent width of [O III] versus optical to radio core flux ratio) is
more consistent with a classification as a NLRG, and this would be consistent
with the observed luminous, heavily absorbed nuclear X-ray component.
This elliptical galaxy is a member of a cluster. At least three diffuse
companions and two pointlike sources are present in the field of view. The
optical image of de Koff et al. (1996) shows also a faint diffuse source.
J0437+2940 (3C 123). - The source has extended structure on the
arcsecond scale over a very broad range of frequencies, from 25 MHz
(Megn et al. 1987) to 98 GHz (Okayasu, Ishiguro, & Tabara 1992). In
our observation, the source is well resolved.
3.8 3C 123
This peculiar FRII radio galaxy is dominated by an X-ray extended
component. Radial profiling does not require a core component, but the
X-ray distribution is complex. Since radial profiling may not be
appropriate, we derive an upper limit on the core contribution from a
15-arcsec source circle around the brightest X-ray peak. The counts we
tabulate are corrected to our standard 1-arcmin source circle and
1-2-arcmin background region. We will discuss this object in more detail
elsewhere (Hardcastle et al., in preparation).
A cD galaxy near center line of close (about 25 arcsec)
unequal radio double with structure not along main axis
Branson, N.J.B.A., Elsmore, B., Pooley, G.G., and Ryle, M.,
(1972) MNRAS, 156, 377.
(1970) MNRAS, 149, 101.
Original Identification by
Wyndham, J.D. (1966) Ap. J., 144, 459,
Matthews, T.A. (1966) A.J., 71, 169,
Longair, M.S. (1965) MNRAS, 129, 419.
A light 200-inch V plate in good seeing shows about 4 fainter
galaxies about 10 arcsec to east: probably a faint cluster.
The cD is within 3 arcsec of the centroid from
Adgie, R.L., and Gent, H. (1966) Nature, 209, 549.
5 arcsec of the center given by
Branson, N.J.B.A., Elsmore, B., Pooley, G.G., and Ryle, M.
(1972) MNRAS, 156, 377.
and 9 arcsec from the center given by
Mitton, S. (1970) MNRAS, 149, 101.
Redshift of z = 0.637 by
Spinrad, H. (1975) Ap. J. (Letters), 199, L3
is confirmed by KSW.