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Notes for object NGC 6951

26 note(s) found in NED.


1. 2008ApJS..174..337M
Re:NGC 6951
NGC 6951 (Fig. 5p).-The ring is small but complete with eight detected H II
regions. The youngest H II region (PA = 339^deg^) is within 16^deg^ of its
respective contact point. The ages steeply increase (by a factor of 10) from
339^deg^ to 218^deg^ in a clockwise direction, consistent with the directional
flow of the galaxy.

2. 2007MNRAS.379.1249D
Re:NGC 6951
NGC 6951 is a spiral galaxy, which has a large stellar bar (PA ~ 90{degrees}).
Its nucleus is classified as Seyfert 2 (Ho et al. 1997), but Perez et al. (2000)
suggest that it could be considered as a transition object, between a very high
excitation LINER and a Seyfert 2 galaxy. The ionized gas (H{alpha}) is mainly
concentrated in the nuclear region and forms an annulus of radius ~5 arcsec, in
which massive star formation is taking place. Perez et al. (2000) interpreted
the H{alpha} kinematics in the circumnuclear zone as a series of nested discs,
decoupled from one another.
The stellar continuum presents isophotes elongated along a PA consistent with
the galactic disc major-axis (PA ~ 138{degree}; Rozas et al. 2002). The stellar
velocity field shows a regular rotation pattern with the major-axis aligned with
the LON of the galaxy. The stellar velocity dispersion shows a drop in the inner
5 arcsec.
The H{beta} emission-line distribution map shows an inner broken ring
elongated along the major-axis of the galaxy (PA = 137{degree}) while [O III] is
dominated by the AGN contribution, its intensity maps showing a compact central
peak in the inner 3 arcsec, with no particular feature outside. The
emission-line ratio [O III]/H{beta} reaches very low values in the ring (0.2),
consistent with the presence of ongoing star formation in the annulus, and rises
towards the centre (values of up to 6) where the effect of the AGN is prominent.
The velocity fields are regular, dominated by the global rotation, and aligned
with the stellar kinematics. The emission-line velocity dispersion rises rapidly
towards the centre reaching about 100 km s^[IMAGE]1^ close to the nucleus for
both the H{beta} and [O III] emission lines. These values are in good agreement
with those found by Perez et al. (2000).

3. 2007AJ....134..648M
Re:NGC 6951
NGC 6951 (Figs. 7.64, 9.64, 20.64): This object shows a very regular ring of
star-forming regions and stellar clusters. Inside the ring the surface
brightness remains constant. The nucleus is diffuse and extended, with a couple
of brighter blobs.

4. 2004A&A...415..941E
Re:NGC 6951
NGC 6951: Suggested as double-barred by Wozniak et al. (1995) and Mulchaey
et al. (1997). However, Friedli et al. (1996) noted that it might be nuclear
ring instead, and NICMOS2 F110W and F160W images confirm the latter
interpretation (e.g., Perez et al. 2000; Martini et al. 2003; Perez-Ramirez et
al. 2000).

5. 2003ApJS..146..353M
Re:NGC 6951
NGC 6951 (LW)
This galaxy has two dust lanes along its large-scale bar, and the
southern one is clearly visible in the color map. The dust lanes end
at the circumnuclear starburst ring, however, and inside of the ring
there appears to be a loosely wound spiral rather than a grand-design
spiral. This galaxy is a prototype of the loosely wound nuclear spiral
class.

6. 2003AJ....126..742H
Re:NGC 6951
The morphological classification as determined by us is indicated in
parentheses next to the galaxy name, with our "chaotic circumnuclear
dust" (C) category now not including those galaxies with obvious dust
lanes (DL). Where the classification has already been made by Martini
et al. (2003), we indicate this with "-mp."
.
3.38. NGC 6951: Intricate Dust Structure (GD) (LW-mp)
Figure 18 (top).
Spectra: The spectra show strong and complex emission-line features.
Some broad features are present in the spectra. The continua appear
faint.
Images: The color map of NGC 6951 displays intricate dust lanes,
forming a weblike appearance. These features have been seen before by
Perez et al. (2000) and are emphasized by these HST images.

7. 2002MNRAS.337..808K
Re:NGC 6951
A12 NGC 6951
Our images of this galaxy (Fig. 1l) suffer from rather poor spatial
resolution, but the strong bar and main spiral arms in the disc can easily
be identified. The B-I image shows a pair of curved dust lanes which
emerges from the CNR and runs roughly parallel to the spiral arms. The
enhanced SF activity in the CNR is obvious from the blue colour in the B-I
map and from the H{alpha} image, but the resolution in the images is too
poor to show much detail (compare, e.g. with the H-band HST image shown in
Paper I). The H{alpha} image shows SF activity across the disc, but none is
observed along the bar. There is also some H{alpha} emission from the
(LINER/Seyfert) nucleus.
We encountered two problems in the process of the ellipse fitting,
resulting in higher than normal uncertainties: the original images had
saturated centres, and no aperture photometry for the I-band was found. We
thus used average values for ?I and B-I as labelled in the appropriate
profiles in Fig. 1l. We see no evidence for an inner bar from our combined
optical and NIR profile fits, contrary to the suggestion of Wozniak et al.
(1995) as based on optical imaging, a suggestion which, however, could not
be unambiguously confirmed by the same team from their NIR imaging (Friedli
et al. 1996).
NGC 6951 (Fig. 2l), like NGC 5248, shows miniature spiral structure in
the HST image, but this spiral is not resolved in our H{alpha} image and
the clumps of massive SF seem to be confined to the ring. As in e.g.
NGC 4314, the regions of massive SF as traced by H{alpha} emission coincide
in radius with the red 'ring' as traced by the J-K image.

8. 2002AJ....124..675C
Re:UGC 11604
S(1.4 GHz) estimated by direct integration on the NVSS image.

9. 2002AJ....123..159C
Re:NGC 6951
Blue ring surrounds red center; red (dust) spiral lanes outside blue ring

10. 2002A&A...389...68G
Re:NGC 6951
NGC 6951: we take the average of our two values which are in
good agreement with the values derived by Grosbol (1985).

11. 2001ApJS..133...77H
Re:NGC 6951
NGC 6951 (S2). - NGC 6951 harbors a Seyfert 2 nucleus which is
surrounded by a 1 kpc diameter circumnuclear starburst ring (Barth et al.
1995). Our full-resolution maps depict the ring with much greater clarity
than in previous radio maps made with similar resolution (Vila et al. 1990;
Saikia et al. 1994). The nucleus, which contains only ~10% of the total
flux in either band, has a steep spectrum ({alpha}_6_^20^ = -0.90).
Although it appears to be slightly resolved in one direction, the apparent
elongation is along the direction of the beam, and we consider the source
to be unresolved.

12. 2000MNRAS.317..234P
Re:NGC 6951
3.12 NGC 6951
The dust structure in the circumnuclear ring is the most conspicuous
feature in our J-K colour index map, but the star-forming regions in the
ring can also be seen in the broad-band images (Fig. 2l). The bar dust
lanes connect to this nuclear ring in the north-east and south-west.
Several sites of SF are located along the ring, and its presence is also
seen in the ellipticity and PA profiles, as well as in all other
profiles (Fig. 2l).
We can also see a blue ring at about 2 arcsec, within the red nuclear
ring surrounding it. This blue ring shows up as a dip in the J-K
profile. Its nature is not clear, and needs further study. The HST H-band
image, used also by Perez et al. (2000), shows a picture also seen in
e.g. NGC 3351 and 4314, namely of bright emitting knots distributed
along tightly wound spiral armlets in the nuclear ring, accompanied by
dust lanes.

13. 1999A&AS..140....1M
Re:NGC 6951
NGC 6951 (UGC 11604)
This is the first galaxy of our sample for which all the necessary data
has been acquired (imaging and spectroscopy); it has been studied in
detail by Perez et al. (1999) and will not be presented here. We just
note that no secondary bar is detected even in NIR HST images.

14. 1998ApJ...496..133B
Re:NGC 6951
NGC 6951.--This low-luminosity Seyfert 2 galaxy hosts a spectacular
circumnuclear star-forming ring with projected dimensions of 1.0x0.7 kpc^2^. The
structure of the ring and its compact star clusters are discussed by Barth et
al. (1995).

15. 1997ApJS..112..391H
Re:NGC 6951
NGC 6951.--No broad H{alpha} line is found in the Seyfert nucleus of this
galaxy (Fig. 14f). The emission lines are slightly asymmetric but are well
separated at our resolution, and a simple two-component model for the
narrow-line profile gives a satisfactory fit to the spectrum.

16. 1997ApJS..110..299M
Re:NGC 6951
Double bar is visible in the K_S_image. The primary bar is also seen in
the ellipse fits, while the bar in the inner 5" is more difficult to
quantify.

17. 1997ApJS..108..155G
Re:NGC 6951
NGC 6951 shows a compact nucleus surrounded by a ring of H II regions.
The ring is elongated and composed of six bright knots of emission not
distributed uniformly along the ring, but piled up toward the ends; see
expanded Figure 11d.

18. 1996ApJS..103...81C
Re:NGC 6951
NGC 6951.--Our 1.425 GHz flux density estimate for this extended radio source
is very uncertain. VLA {lambda} = 6 cm B-configuration maps of the core in
Saikia et al. (1994) and in Vila et al. (1990); D-configuration map in Condon
et al. (1995). VLA A-configuration map of the core at 1.49 GHz in Vila et al.
(1990).

19. 1996A&AS..118..461F
Re:NGC 6951
NGC 6951. We cannot unambiguously confirm the secondary bar suggested in
Paper I due to the strong isophote twists. This twisted structure is surrounded
by a red (J - K ~ 1.35) nuclear ring visible on J - K colour map while the
surrounding region has J - K ~ 1.0. The morphology of this ring is roughly the
same on H{alpha}, B - I and J - K maps. Moreover, the VLA radio maps of Saikia
et al. (1994) show a spiral-like structure in the gas component which is
compatible with the presence of a bar. However, the biggest J - K spot located
N (on the original J - K map but badly reproduced on the greyscale figure) is
not exactly coincident with the corresponding one in the B - I map
(cf. NGC 5905). Also, the reddest part of the J - K ring is in the SW, where
the dust darkening is the greatest. The various hotspots are in fact
spectacularly resolved into numerous smaller star forming regions with HST
V-image (Barth et al. 1995). Their image does not show any secondary bar. It is
thus not clear if the observed twists could result from the few intense sites
of star formation along the nuclear ring and/or the dust pattern inside the
ring.

20. 1995ApJS...98..477H
Re:NGC 6951
As noted in Paper I, the emission-line intensity ratios and profiles of
NGC 6951 (Fig. 96) closely resemble those of NGC 5194 (Fig. 81). Both
objects can be classified as Seyfert 2 galaxies based on their emission-
line spectra. Filippenko (1984) further discussed similarities in the
spatial variation of the [N II] {lambda}6583/H{alpha} ratio in these two
galaxies. The radial gradients of the emission-line intensity ratios in
NGC 5194 have been attributed to photoionization by a power-law radiation
field (Rose & Searle 1982).

21. 1994CAG1..B...0000S
Re:NGC 6951
Hubble Atlas, p. 46
Sb/SBb(rs)I.3
PH-5374-S
Sep 11/12, 1969
103aO + GG13
25 min
The relative straightness of the two opposite
dust lanes within the central disk of NGC 6951
identifies the central region as an oval rather
than simply an inclined circular disk. However,
the bar (the oval) is weak; the spiral pattern is
open, and there is no enhanced star formation at
the ends of the bar.
The HII regions in the arms are unresolved
at the 1" level. The redshift of NGC 6951 is
v_o = 1710 km/s.

22. 1976RC2...C...0000d
Re:NGC 6951
= NGC 6952

23. 1973UGC...C...0000N
Re:UGC 11604
SAB(rs)bc (de Vaucouleurs), Sb+ (Holmberg)

24. 1964RC1...C...0000d
Re:NGC 6951
= NGC 6952
Extremely bright nucleus with innermost (r) and an extremely small nucleus.
Broad bar: 1.2 arcmin x 0.3 arcmin in a lens: 2.3 arcmin x 1.4 arcmin. 3 main,
partially resolved arms with some branches.
Magnitude:
Ap. J., 85, 325, 1937.

25. 1961Hubbl.B...0000S
Re:NGC 6951
SBb(s)/Sb
PH-113-H
Sept. 24/25, 1951
103aO
30 min
Enlarged 5.0X
This galaxy, which has features of both SBb(s) and Sb
systems, is a transition between these two "pure" spiral
types. The two straight dust lanes are prominent. In
form this galaxy is similar to NGC 1097 (above).

26. 1918PLicO..13....9C
Re:NGC 6951
Rather faint, symmetrical spiral 3.5' in diameter. Very bright, slightly oval
nucleus 0.2' long. {phi}-type. 2 s.n.


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