Date and Time of the Query: 2019-07-20 T18:41:28 PDT
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Notes for object NGC 7172

13 note(s) found in NED.

1. 2009ApJ...702.1127R
Re:NGC 7172
NGC 7172 is a Type-2 Seyfert nucleus in a nearly edge-on spiral
galaxy. A prominent dust lane in the east-west direction crosses the galaxy.
Similar to the case of NGC 4388, we observe a near-IR bump of emission in the
SED of NGC 7172, which stellar contamination of the seeing-limited fluxes likely
produces (Section 5.2). The N_0_ histogram shows a Gaussian shape, with median
value N_0_ = 5 +/- ^3^_1_. High values of i, {sigma}, and q are more probable (i
> 45^deg^, {sigma}>54^deg^, and q > 1.7, respectively), while low values
of {tau}_V_ are preferred ({tau}_V_ < 12). The torus produces optical extinction
A^LOS^_V_ = 50 +/- 20 mag. The reprocessing efficiency of this galaxy is high
(~80%), according to the derived values of the AGN and torus bolometric
luminosities. T-ReCS mid-IR spectroscopy shows a substantial silicate absorption
feature (Roche et al. 2007) that is not reproduced by the fitted models, that
predict it in very extremely emission (and self-absorbed). This could be due to
the above-mentioned stellar contamination of the near-IR fluxes, that in
addition to the lack of Q-band data point for this galaxy, make it difficult the
correct reproduction of the silicate feature in absorption.

2. 2002A&A...386..379R
Re:NGC 7172
NGC 7172: there are two published works on the analysis of the same
data (Akylas et al. 2001; Dadina et al. 2001). Akylas et al. (2001)
propose a model with no reflection. Their best fit parameters are
in agreement with our model B (Table 4). Dadina et al. (2001) find
that the inclusion of a cold reflection slightly increase the
goodness of the fit. The best fit slope of the continuum is
significantly higher in this model Our results are in agreement
with Dadina et al. (2001). Our best fit model C (Table 5) is only
slightly better than model B, and predicts a steeper intrinsic
continuum ({GAMMA ~ 1.9), than model B ({GAMMA} ~ 1.7, in agreement
with Akylas et al. 2001).

3. 1999A&AS..137..457M
Re:NGC 7172
NGC 7172: This object has a linear radio structure (Figs. 3 and 4) which
is elongated roughly east-west (PA_radio_ = 90^deg^). A 13 cm core flux
of 3 mJy has been detected with the PTI (R94).

4. 1997ApJS..113...23T
Re:NGC 7172
A23. NGC 7172
NGC 7172 is a member of the compact group HCG 90, and it has a prominent
equatorial dust lane (Sharples et al. 1984). Deep optical observations indicate
that the galaxy is severely distorted by tidal effects, while the nuclear
emission spectrum is found to be indicative of excitation by a power-law
photoionization source. Strong infrared emission is also observed from the
nucleus, which is variable on a timescale of approximately 3 months (Anupama et
al. 1995). EXOSAT obtained the first X-ray spectrum of the source, which showed
a {GAMMA}=1.84 power law absorbed by N_H_~10^23^ cm^-2^ (Turner & Pounds 1989).
The ASCA spectrum of faint source was adequately fitted with a spectrum
consistent with the EXOSAT result. The source was too faint for the ROSAT HRI
observation to allow any interesting constraints on spatial extent.

5. 1997ApJ...477..631V
Re:NGC 7172
NGC 7172 has been tentatively identified with the HEAO A-2 hard X-ray
source H2158-321 (Marshall et al. 1979). Its nuclear emission spectrum is
indicative of excitation by a power-law photoionization source (Sharples
et al. 1984). The large narrow-line Balmer decrement in this galaxy
(>6.5; Sharples et al. 1984) indicates substantial obscuration (A_V_ >
2.5 mag) and makes it a good target to search for an obscured broad-line
AGN through infrared spectroscopy. The K-band spectrum of NGC 7172 is
shown in Figure 2x. No J-band data were taken of this galaxy. The
emission around Br{gamma} appears dominated by continuum emission from
the underlying stellar component. The H_2_{lambda}2.121 line is barely
detected at 2.14 microns, and only an upper limit to the Br{gamma}
intensity could be derived. An upper limit of 6 x 10^-15^
ergs s^-1^ cm^-2^ to the [Fe II]{lambda}1.64 flux was derived by Moorwood
& Oliva (1988).

6. 1996ApJS..103...81C
Re:NGC 7172
NGC 7172.--Seyfert 2. VLA A-configuration map of the core at 1.49 GHz in Unger
et al. (1987).

7. 1996AJ....111..712H
Re:NGC 7172
2159-321 (NGC 7172). This galaxy looks like a fat disk seen edge-on, with a
very wide and long dust lane. There are bright knots out of the plane on one
side. A large number of fainter objects was measured, presumably because of the
smooth and dark nature of the background. More faint objects are found on the
same side as the clearly visible bright ones, and none of the objects on the
"poor" side is blue, which suggests that the dust lane extends out of the
galaxy, as in 0140+134.
The distribution of knots that lie inside the galaxy, define a redder and
fainter population than the knots outside, as also seen also in 0140+134.
Dereddening to the main sequence yields luminosities that all exceed 100
M_sun_ stars.

8. 1996A&AS..117..417H
Re:ESO 466- G 038
23. ESO 466-38 / NGC 7172: nearly edge-on galaxy, with a strong absorbing lane
in B parallel to the major axis (extinction {delta}_{mu}B_ ~2). In K`, the lane
is barely visible; bright central disk (inner isophotes with e_4_ ~0.07).

9. 1994A&A...282..418L
Re:NGC 7172
NGC 7172: due to restrictions in observing time, the avaiable data
extend only up to ~10" from the center. The central velocity dispersion
of the bulge is 180 +/- 40 km s^-1^, but no reliable velocity dispersion
profile could be derived from the available data. The rotation curve is
shown in Fig. 2.
Within the rather large errors, it looks symmetric and does not show
any appreciable distortion. It needs to be stressed, however, that it
refers only to the central regions of the galaxy where kinematics is very
unlikely to be affected by tidal interaction with the other members of
the group.

10. 1985SGC...C...0000C
Re:NGC 7172
Plate 691
Dust lane, very faint extension.
Plate 2532
Overall dimensions include plume: [10:: x 5.5:].

11. 1982ESOU..C...0000L
Re:ESO 215907-3206.6
=ESO 466- G 38
irregular dust lane
in cluster

12. 1976RC2...C...0000d
Re:NGC 7172
In small group or chain with NGC 7173, NGC 7174, and NGC 7176.
Photograph and Spectrum:
Ap. J., 191, 645, 1974.

13. 1964RC1...C...0000d
Re:NGC 7172
In the NGC 7163-7176 Group.

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