UGC 4284. The rotation curve is more symmetrical using a kinematical centre 5
arcsec south from the morphological centre. However, to have a consistent
analysis with the rest of the sample, we decided to keep the morphological
NGC 2541 (Fig. 16.42).-The conspicuous outer spiral structure of this SA(s)cd
LINER galaxy detected in our GALEX observations is not seen at all in the
2MASS-K_S_ imagery, and only partially in visible light. SDSS imaging shows a
few faint sources in the XUV-disk LSB zone. H I observations from WHISP and
Broeils & van Woerden (1994) show that the galaxy has an extended gas
distribution. NGC 2541 is the brightest galaxy in a small group (of 3+?), but
isolated according to tidal perturbation parameter analysis.
4.5 UGC 4284 This Scd (barred according to the de Vaucouleurs
classification) galaxy has an elongated bulge and a diffuse spiral
structure. Due to the fact that the optical limit is larger than our
field of view, we miss the most external parts. There are H II regions
along a barred structure in the centre and all along the spiral
arms. The bar extends up to 30 arcsec, which corresponds to the first
bump on the rotation curve. The rotation curve is quite symmetric and is
rising until 130 arcsec, maybe reaching a plateau at 110 km s^-1^. The
central isovelocity lines (550 and 570) show kinks along the bar. The
global pattern betrays a warp of the disc; on the H I map provided by
WHISP, this warp is clearly visible. The position-velocity plot of WHISP
shows that a plateau is reached around 2 arcmin, then there is a
decrease of the velocities on the approaching side beyond 4 arcmin,
likely due to the warp.
Diffuse radio source.
The bright central component in this PV diagram is
characterized by the same velocity dispersion measured in the
outer parts of the disk. This is typical of Type III diagrams.
NGC 2541: The H I data by Broeils & van Woerden (1994) show a symmetric
outer rotation curve with no particular peculiarities.
NGC 2541. - We did not detect compact structure, not even on the
tapered map. This source was also not detected in the FIRST or in the
NVSS survey. However, Condon (1987) reports a possible detection at
1.49 GHz, 0.8' resolution, of a 3.2 mJy source, slightly extended to the
southwest relative to the optical position of the galaxy.
March 16/17, 1950
NGC 2541 is highly resolved into individual
HII regions. The largest three of the more than
50 such regions identifiable on this short-exposure
Palomar 200-inch plate have resolved
disks at the 3"-diameter level.
NGC 2541 is near the middle of a loose
group of at least four highly resolved late-type
galaxies, all in the RSA, already mentioned in the
description of NGC 2500 (Sc; panel 262). The
mean redshift of the group is
The individual redshifts are v_o(2500) = 615 km/s,
v_o(2537) = 513 km/s, v_o(2541) = 646 km/s,
and v_o(2552) = 607 km/s. The angular
separations and corresponding projected linear
separations from NGC 2541, based on a mean
redshift distance of 11.9 Mpc (H = 50), are 2.6^deg^
and therefore 540 kpc for NGC 2500, 3.1^deg^ and
644 kpc for NGC 2537, and 1.2^deg^ and 249 kpc
for NGC 2552. These projected linear separations
are similar to distances within the Local Group.
Note the similarity of the HII-region brightness
distribution and the spiral pattern in all
members of the group, seen on panels 262, 275,
and 322 in addition to the panel here.
Our CO(1-0) upper limit of 0.9 K km/s (based on the rms noise and
assuming a line width of 260 km/s, roughly equal to the zero-level HI
line width) for the central 23" corresponds to a H_2_ mass limit of about
3 x 10^6^ M_sun_. Our radial data have a higher noise level which makes
it difficult to place a meaningful upper limit on the total H_2_ mass.
In group with NGC 2500 and NGC 2552.
SA(s)cd (de Vaucouleurs), Sc+ (Holmberg)
"In group with NGC 2500, NGC 2552" (de Vaucouleurs)
Very small, faint nucleus in smooth center (as in Messier 033), many
In a group with NGC 2500 and NGC 2552.
Heidelberg Veroff. Vol. 9, 1926
dimensions (4.0: arcmin x 1.8: arcmin) for the bright part only.