5.5 NGC 3958-63
NGC 3963 is a Grand Design spiral [Figs. 9(a) and 9(b)] with a bright central
nucleus and a very prominent thick bar. The companion edge on galaxy NGC 3958
(to the south west) has a bright nucleus with two fainter knots on either side
along the major axis and diffuse spiral arms. Figure 9(a) shows faint emission
from NGC 3958 extending away from its larger neighbor. Both galaxies have
central H I depressions.
There are two faint uncataloged galaxies to the south of NGC 3963 [Figs. 9(a)
and 9(b)], and there is also extended H I emission in the same area; however,
it is not clear if the two are related. There appears to be no connection
between the long extended optical emission seen in Fig. 9(a) and the spiral
structure within the main galaxy NGC 3963. It is possible that these two faint
galaxies are simply a background interacting pair, or that the highiy extended
galaxy is a gas poor companion to NGC 3963 in the processes of being tidally
The southern edge of NGC 3958 has a greater redshift [Fig. 9(c) and 9(d)] than
the northern edge, and the systemic redshift of NGC 3958 itself is greater than
that of NGC 3963; NGC 3958 is hence undergoing a direct encounter. The
extension seen to the south of NGC 3958 is probably a counter tail, consistent
with this encounter geometry. Figure 10 is the simulated single dish H I
Feb 7/8, 1981
The plate used here for NGC 3963 was
taken through clouds and gives a false impression
of the true surface brightness of the galaxy; the
sky was thick, decreasing the surface-brightness
contrast between the galaxy and the night sky
The plate was taken with a Racine wedge.
The secondary images are faintly visible for (1)
the brightest star in the field, superposed on one
of the arms below and to the right of center, and
(2) the nucleus, which is almost starlike upon
visual inspection at the telescope, evidenced here
also by the secondary image made by the wedge.
The spiral pattern is of the grand design
rather than of the multiple-armed type. Only two
principal arms exist; one, highly regular, can be
traced for almost a whole revolution, while the
other branches into two after half a revolution.
The redshift is v_o = 3295 km/s.
Pair with NGC 3958 at 8.2 arcmin
SAB(rs)bc (de Vaucouleurs)
A beautiful object with 2 symmetric arms visible through 360^deg^
See UGC 06880
Small, very bright nucleus in a bright bar: 0.5 arcmin x 0.3 arcmin.
Pseudo (r): 0.5 arcmin x - . 2 main massive, knotty bright arms.
Heidelberg Veroff. Vol. 9, 1926 dimensions are for the bright part only.
Non-interacting pair with NGC 3958 at 8.2 arcmin.
Ap. J., 85, 325, 1937.