UGC 5250: ORC slightly truncated by edge of slit on left side.
NGC 2998: short Westerbork observations (Broeils & van Woerden 1994) show
its H I distribution to be symmetric but not very extended compared to its
optical dimensions. Full Westerbork H I synthesis mapping (Broeils 1992)
show that its H I disk has a diameter of 3.8' (1.3 D_25_) and a regular
velocity field with a classical, flat rotation curve at
V_rot_ = 210 km s^-1^.
Three small spiral companions were detected in H I at Westerbork:
NGC 3002, NGC 3006 and MCG 07-20-057. These are B_T_ 15-16 mag objects at
distances of 5' to 12' from NGC 2998, of about 0.65' diameter and with
integrated H I fluxes ranging from 1.7 to 5.1 Jy km s^-1^ at about the
same systemic velocity as NGC 2998 (Broeils 1992). They lie well outside
the Nancay HPBW, but can cause some confusion in Green Bank and Jodrell
Bank profiles of NGC 2998. Our Nancay profile (estimated
I_HI_ = 17.5 Jy km s^-1^) agrees well with that of Theureau et al. (1998).
The Green Bank (7.0 Jy km s^-1^) and Jodrell Bank fluxes (31.9 Jy km s^-1^)
are quite different, though central velocities and linewidths are
consistent between all available profiles.
KUG 0945+443 (NGC 2998, IRAS F09455+4418)
The morphological index is T=5. This galaxy has extremely
well-developed knotty arms. It lies in a loose group, and there is a
faint irregular galaxy lying at 5' (~60 h^-1^ kpc) to the east. They do
not appear to be bridged or to have any features that imply
This is also a giant spiral galaxy. The dispersion of colors across the
galaxy is large, implying that the ages of the SF regions on the disk
range from 5 x 10^7^ yr to 10^9^ yr. The most crowded domain on the C-C
diagram corresponds to the 10^8^ yr phase of the 10% or 1% burst mass
tracks. Its bulge (labeled "12") is red, as expected from an old stellar
Nov 27/28, 1946
The spiral pattern of NGC 2998 is of the
same type as that of the other five galaxies on this
panel. Five arm crossings can be counted on each
side of the major axis. The arms are thin and
very well defined, requiring the early luminosity
The reproduction here is made from a plate
taken in excellent seeing with the Hooker 100-inch
telescope on Mount Wilson.
The redshift of NGC 2998 is large, at
v_o = 4813 km/s.
= Holm 144a
Non-interacting pair with an anonymous SB(s)m pec
at 4.5 arcmin south-following.
Brightest galaxy in the NGC 2998-3010 Group.
SAB(rs)c (de Vaucouleurs)
09 46.1 +44 15 = NGC 3006 at 6.9, 120, 0.7 x 0.15, m=15.6
09 46.2 +44 08 at 11.7, 147, 0.9 x 0.3, m=15.2
09 46.4 +44 19 = NGC 3008 at 9.1, 84, 0.5 x 0.3, m=15.4
NGC 3000 is a double star north-following
= Holm 144a
Very small, bright nucleus. Pseudo (r): 0.35 arcmin x 0.17 arcmin. Many
filamentary knotty arms.
Non-interacting pair with anonymous SB(s)mp at 4.5 arcmin south-following.
Brightest in the NGC 2998-3010 Group; NGC 3000 (= Holm 144e) is a double star.