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Notes for object NGC 3198

17 note(s) found in NED.


1. 2009A&A...503..409H
Re:NGC 3198
No significant polarized emission is detected in this target, apart from a
possible detection of the nucleus. An equal brightness double source in the
field allows a very consistent assessment of the Galactic foreground RM of +7
+/- 2 rad m^-2^.

2. 2008AJ....136.2648D
Re:NGC 3198
4.8. NGC 3198 is known for its prototypical flat rotation curve (see van Albada
et al. 1985). We compare our rotation curve with those derived by Begeman (1987,
1989) and Sicking (1997) in Figure 12. The systemic velocities agree within
their respective 1{sigma} uncertainties: our result is 660.7 +/- 2.6 km s^-1^,
Begeman (1989) finds 660.4 +/- 0.8 km s^-1^, whereas Sicking (1997) finds 659.4
+/- 2.6 km s^-1^. The respective average P.A. and i values only show differences
<~1^deg^.

3. 2008AJ....136.2648D
Re:NGC 3198
6.7. NGC 3198 The surface brightness profiles of NGC 3198 are shown in Figure
36. The 2MASS J, H, and K profiles can be traced out to ~240", and the 3.6 {mu}m
profile out to ~250". The profiles show a central component, as well as a
"shoulder" in the surface brightness around R ~ 50". We initially model the
system using two components. For the innermost component we use an exponential
disk with parameters {mu}_0_ = 15.4 mag arcsec^-2^ and h = 0.56 kpc. The profile
of the main disk is derived by subtracting the inner component model from the
total luminosity profile and is extended beyond R ~ 240" by an exponential disk
model with {mu}_0_ = 16.2 mag arcsec^-2^ and h = 3.06 kpc. The most striking
feature in the (J - K) color distribution is the sudden reddening in the
innermost couple of arcseconds. At face value, this would imply a steep increase
in {GAMMA}^3.6^_*_ in the innermost parts. This might indicate an additional
(third) compact, central component. Alternatively, it could indicate the
presence of a centrally-concentrated pronounced dust component. Whatever the
cause, the steep increase in color only affects the very innermost point of the
rotation curve and we will not model it. Adding a third component would increase
the number of possible parameter combinations, but without obvious benefit. We
therefore adopt the {GAMMA}^3.6^_*_ profile as observed, but assume a constant
{GAMMA}^3.6^_*_ = 0.8 for R > 125", as well as a constant {GAMMA}^3.6^_*_ = 0.7
for R < 10", as indicated in Figure 36. The rotation curve fits are shown in
Figure 37.

4. 2008AJ....136.2648D
Re:NGC 3198
In the case of fixed {GAMMA}^3.6^_*_, the inner component clearly
overestimates the rotation velocity, indicating that it is likely to be
dynamically less important than suggested by the models (assuming the rotation
curve is not affected; see below). With {GAMMA}^3.6^_*_ as a free parameter, the
outer disk ends up being less massive than predicted for both models. The
central component is also fitted with a much smaller {GAMMA}^3.6^_*_. For the
ISO model, we find an inner component ~10 times lighter than predicted, whereas
the NFW model results in a negative, hence unphysical, value for
{GAMMA}^3.6^_*_. We therefore fixed its value to {GAMMA}^3.6^_*_ = 0, with
little impact on the results for the outer disk. We checked whether modeling the
inner component as a spherical bulge instead of an exponential disk changed the
results, but found this had a negligible effect on the outcome. Because of the
apparent insignificance of the i nner component, we also investigated if a
single-disk model could explain the data. The results are also given in Figure
38. It is clear that independent of the choice for halo model, the inner radii
cannot be well fitted. The small value of {GAMMA}^3.6^_*_ for the inner disk
makes the free {GAMMA}^3.6^_*_ fits less satisfactory. The low {GAMMA}^3.6^_*_
values in the inner parts seems to contradict the sudden reddening in the inner
10", suggesting a higher {GAMMA}^3.6^_*_ value. A close inspection of the IRAC
3.6 {mu}m image indicates the presence of a short bar at a small angle with the
minor axis, which could mean that the rotation velocities are affected by
noncircular motions, thus giving incorrect values for {GAMMA}^3.6^_*_. However,
a harmonic decomposition of the velocity field shows only small noncircular
motions (of order a few km s^-1^) in the inner parts of the disk; see
Trachternach et al. (2008). In an independent analysis, Bottema et al. (2002)
also note the presence of a possible bar in a K' image of NGC 3198. They argue
that having a bar roughly parallel to the minor axis would increase the apparent
rotation velocities in the inner region (Teuben & Sanders 1985). If this is
indeed what is happening in NGC 3198, then the true rotation velocity in the
inner parts must be even lower than we now observe, thus making the inner disk
even less massive. Clearly there is scope here for a more extensive study of the
dynamics in the inner part of NGC 3198.

5. 2007ApJS..173..538T
Re:NGC 3198
NGC 3198 (Fig. 16.13).-This inclined SB(rs)c galaxy was studied in some detail
following the discovery of an apparent sharp outer edge to the H I distribution
(Maloney 1993; van Gorkom 1991). H I extends to at least 634" radius, about 2.5
times D_25_ radius (Sicking 1997). The H I distribution is asymmetric, with a
filament in the northeast portion of the galaxy (Bosma 1981; Sicking 1997;
THINGS). GALEX shows that SF is occurring in spiral waves throughout the known
extent of H I, with lower average UV surface brightness in the XUV-disk.
Nevertheless, localized UV-bright clumps are obvious even in the most extended
parts of the H I disk. As expected, patterns in the distribution of XUV
complexes are tied to arm features in the H I morphology of NGC 3198. We can
discern SDSS detections for a limited number of the brightest inner XUV-disk UV
complexes. NGC 3198 is the brightest member of group containing five galaxies,
including NGC 3319 (a Type 2 XUV-disk). However, computation of a tidal
perturbation pa rameter (see {section} 3.3.3) indicates that NGC 3198 is
effectively isolated in terms of tidal interaction.

6. 2006MNRAS.366.1265B
Re:NGC 3198
This SB(rs)c galaxy has been extensively studied in H I (Bosma 1981; Begeman
1989), FP H{alpha} (Corradi et al. 1991; Blais-Ouellette et al. 1999) and
H{alpha} and [N II] long-slit spectroscopy (Sofue et al. 1998; Vogt et al.
2004). According to the PV diagram, non-circular motions near the centre can be
seen. A strong velocity gradient is also seen perpendicular to the bar major
axis.

7. 2005MNRAS.360.1201H
Re:NGC 3198
NGC 3198. This SB(rs)c galaxy has been extensively studied in H I (Bosma 1981a;
Begeman 1989), FP H{alpha} (Corradi et al. 1991; Blais-Ouellette et al. 1999)
and H{alpha} and [N II] long-slit spectroscopy (Sofue et al. 1998; Vogt et al.
2004). According to the PV diagram, non-circular motions near the centre can be
seen. A strong velocity gradient is also seen perpendicular to the bar major
axis.

8. 2002A&A...389...68G
Re:NGC 3198
NGC 3198: there is a good agreement between our two methods for
this quite inclined galaxy. There is also a general agreement
with the rest of methods. The projected HII region distribution,
however, seems somewhat irregular, and this may bias our two
methods, giving higher values from the PA. For this reason we
prefer to adopt the mean values from the HI kinematical studies
of Bosma (1981) and Begeman (1987). Note that these are in good
agreement with our second method and reasonable agreement with
the first.

9. 2001A&A...368...16M
Re:NGC 3198
18. NGC 3198 is an Sc spiral of fairly high inclination, showing numerous
HII regions (Corradi et al. 1991). In the HST key project the Cepheid
distance of NGC 3198 was determined to 14.5 Mpc (Kelson et al. 1999).

10. 1998PASJ...50..427S
Re:NGC 3198
NGC 3198: This is a highly tilted SBc galaxy. The nuclear component
shows a rapid increase of rotation within 2", while its rotation
velocity is as small as 50 km s^-1^. The rotation velocity, then,
increases smoothly to a maximum at R ~ 60", followed by flat rotation.
The HNR value is for the H II regions, and remains nearly constant
through the disk and the nuclear component.

11. 1997AJ....114.2428S
Re:NGC 3198
NGC 3198: The PV diagram appears to consist of two components: a steeply rising
ridge, attaining a high-velocity peak within 20". and a rigidly rising
component with a milder slope. The first rotation peak of V~170 km s^-1^ occurs
at r=23" (1100 pc). The rigid-body component has a gradient of 110 km s^-1^ in
30" (1.4 kpc), probably due to a ring or arms of a radius of about 30".

12. 1994CAG1..B...0000S
Re:NGC 3198
Sc(s)I-II
PH-7960-S
Nov 8/9, 1980
103aO
12 min
The arms in NGC 3198 are moderately thin
and fairly well defined. However, the inclination
angle is so high that the pattern, although
regular, is not easily traced. If one views the
image at an angle and at an optimum orientation
by tipping and rotating the panel to compress the
major axis until it is equal to the minor axis, the
image presents two principal arms that start at
the center [the (s)-type attachment to the center].
Each can be traced for about half a revolution
before each branches to form the multiple pattern.
The redshift of NGC 3198 is small, at 702
km/s, but the HII regions remain unresolved at
the 2" level.

13. 1993A&AS...97..887B
Re:NGC 3198
NGC 3198
We have detected CO emission in the center, but the line ratio is
uncertain. The emission in the "ring" at (26", 37") is about as strong as
the nuclear emission (see spectra) and extends to within 20 km/s of the
edge of the HI spectrum. On both sides of the (26", 37") position the CO
emission decreases, strengthening the idea of a ring rather than simply a
disk. Extrapolating the CO emission we calculate an H_2_ mass close to
10^9^ M_sun_, 20-25% of the HI mass.

14. 1976RC2...C...0000d
Re:NGC 3198
Photograph:
Sov. A.J., 13, 423, 1969.
Rotation Curve and Systemic Velocity:
Astr. Ap., 8, 364, 1970.
SN1966J
IAU Circ. No. 1986, 1966.
IAU Circ. No. 1992, 1967.
Ast.Tsirk. No. 397, 1967.
Ast.Tsirk. No. 412, 1967.
Ast.Tsirk. No. 674, 1972.
J. Observateurs, 51, 5, 1968 = Cont. IAP, Paris, B, No. 349.
Mem. S.A. Ital., 39, 189, 1968 = Cont. Asiago No. 205.
Sov. A.J., 13, 423, 1969.
Izv. Crimea Obs., 41-42, 367, 1970.

15. 1973UGC...C...0000N
Re:UGC 05572
SB(rs)c (de Vaucouleurs), Sc- (Holmberg)
SN 1966j

16. 1964RC1...C...0000d
Re:NGC 3198
Small, very bright nucleus in bar, partially obscured on one side. Pseudo (r):
1.75 arcmin x 0.5 arcmin. Several knotty, partially resolved branching arms.
Lund 9, Heidelberg Veroff. Vol. 9, 1926 dimensions are for the bright part only.
Spectrum:
IAU Symp., No. 5, 1958 = Lick Cont.II, No.81, 1958.
Ap. J., 135, 698, 1962.

17. 1918PLicO..13....9C
Re:NGC 3198
Vol. VIII, Plate 23. A beautiful, moderately bright spiral 9' x 3' in p.a.
40^deg^. Small, almost stellar nucleus and numerous almost stellar
condensations. 28 s.n.


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