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Date and Time of the Query: 2019-06-25 T00:40:48 PDT
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Notes for object NGC 2768

14 note(s) found in NED.


1. 2008A&A...488..523H
Re:NGC 2768
According to ASC this is an E6. van den Bergh et al. (2003) assign type E3/Sa,
indicating doubts about its type. A dual E-Sa class was also assigned by Maund &
Smartt (2005). In NED, its morphology is reported as S0_1/2_ and its activity
class is LINER. The NED information is from The Carnegie Atlas of Galaxies
(Sandage & Bedke 1994) in which the following description is presented: "The
definite outer envelope of NGC 2768 surrounding an E6 bulge makes S0
classification certain. Very subtle dust patches on either side of the major
axis at the ends of the minor axis requires S0_1/2 classification". This galaxy
has blue integral colours (U-B=-0.43 and B-V=0.92) and it is registered as a CO
(Wiklind et al. 1995) and HI emission source (Huchtmeier et al. 1995) and a
source of 1.4 GHz radio continuum emission (Condon et al. 1998). Perhaps the
most interesting information relates to the nuclear and near-nuclear regions of
this galaxy: according to Michard & Marchal (1994) "...the inner isophotes of
the galaxy are boxy, but become disky in the range of 75-115 arcsecs". According
to Lauer et al. (2005) and McDermid et al. (2006) this galaxy has a
dust-obscured central region (spiral dust lanes), central disky gas distribution
and a LINER nucleus with strong emission lines. The stellar population in the
central region of this galaxy is relatively young. The resolution of our images
was not sufficient to analyze in detail the central nuclear structure, but from
its outer structure this object is a classical S0 type. SN2000ds, classified as
type Ib (Filippenko & Chornock 2000) is located far from the peculiar nuclear
region of the galaxy. Detailed study of the SN position by van Dyk et al. (2003)
shows that "...reddish clusters of stars may be evident near the position of the
SN at the 3-4 {sigma} level".

2. 2006MNRAS.369..497K
Re:NGC 2768
This galaxy with a rather cylindrical velocity field shows regular metal line
strength gradients. The H{beta} map appears rather flat. Significant dust
extinction is present north of the centre (Michard 1999).

3. 2006MNRAS.366.1151S
Re:NGC 2768
This galaxy is known for hosting a central dust lane along the minor axis (Kim
1989) and for showing a kinematic decoupling between stars and gas (Bertola et
al. 1992) that was later interpreted as the result of a gaseous polar-disc
structure (Fried & Illingworth 1994). The SAURON maps further reveal remarkably
different distributions for the [O III] and H{beta} emission. The [O III] lines
follow a twisted pattern that is misaligned by ~45^deg^ from the direction of
the dust lanes, while the H{beta} distribution appears to be rounder. HST
narrow-band images by Martel et al. (2004) show that the H{alpha}+[N II]
emission in the central arcsec also follows an integral-sign pattern that is
decoupled from the orientation of the dust. The [O III] velocity field is well
defined, showing peculiar and almost symmetric twists at ~10 arcsec from the
centre. Overall, the gas motions are almost perpendicular to the stellar ones.
The {sigma}_gas_ map shows an elongated peak parallel to the zero-velocity
curve, consistent with the obser vations of Bertola et al. (1995), and possibly
also a rise of {sigma}_gas_ corresponding to the peculiar twists in the velocity
field. The criss-cross appearance of the [O III]/H{beta} maps can be interpreted
in light of the different shapes of [O III] and H{beta} distributions.

4. 2004MNRAS.352..721E
Re:NGC 2768
NGC 2768: This galaxy shows a rather cylindrical velocity field, with a
shallow gradient across the rotation axis (Fried & Illingworth
1994). There is a pronounced dip in the central dispersion field, also
clearly present in the data of Simien & Prugniel (1997b). Significant
dust extinction is present north of the centre (Michard 1999).

5. 2002A&A...388...50F
Re:NGC 2768
The presence of a definite outer envelope with subtle dust
patches surrounding the bulge (see panels 38 and 53 in CAG)
supports the S0 classification of this galaxy, which appears
as an E6* in RC3. The kinematical decoupling between the
ionized gas and the stars, detected by Bertola et al. (1992),
has been interpreted as a result of the presence of gas
orbiting in a polar ring (Mollenhoff et al. 1992;
Fried & Illinghworth 1994). The inner velocity gradient is
higher than the outer one which is one of the lowest we
measured (({DELTA}V/{DELTA}r)_out_ = 0.09 km s^-1^ pm^-1^).
The constant velocity dispersion and the steep increase of
[N II] flux in the center imply a Type III classification
for this PV diagram.

6. 1999A&A...349...88K
Re:NGC 2768
4.3. NGC 2768
No broad H{alpha} component was detected by H97. Weak CO emission was
found by Wiklind et al. (1995). The source is included in a sample of
galaxies by Davis & White (1996) who fit a Raymond-Smith model and find
kT ~ 3 keV for metal abundances 0.2 x solar, and absorption of
N_H_ = 1.9 10^20^ cm^-2^, less than the Galactic value.
The source seems to be slightly variable from the first to the
second pointing with a drop in countrate from 0.021 +/- 0.002 cts s^-1^
to 0.013 +/- 0.003 cts s^-1^. The short-term light curve (first
pointing) shows constant source flux.
Spectral fits were performed for the deeper PSPC observation only.
Neither a single powerlaw with N_H_ = N_gal_ nor emission from a
Raymond-Smith plasma with solar abundances provides a successful X-ray
spectral fit. The fit becomes acceptable for very subsolar abundances.
In that case we find a lower temperature than Davis & White (1996) (and
cold absorption consistent with the Galactic value, which should not be
underpredicted). This T also is more consistent with the kT - {sigma}
relation of Davis & White.
A comparison of the source's spatial extent with the theoretical
point spread function (PSF) of a point source shows that most of the
X-ray emission is consistent with arising from a point source (Fig. 3).
There may be some extended emission at weak levels (Fig. 2). A nearby
weak second source is detected with a countrate of
0.003 +/- 0.001 cts/s. It coincides with a stellar object on a POSS
plate.

7. 1997ApJS..112..391H
Re:NGC 2768
NGC 2768.--Although the total H{alpha}+[N II] blend hints at the probable
presence of weak, broad H{alpha} wings, this suspicion is not confirmed by more
detailed line decomposition (Fig. 8h). This object is one of the rare cases in
which the [S II] lines are actually broader than the [N II] lines, although the
magnitude of the difference is not great and needs to be evaluated more
thoroughly.

8. 1995A&A...297..643W
Re:NGC 2768
NGC 2768. This is an isolated elliptical galaxy with a small dust lane
parallel to the minor axis and very red colours (Kim 1989). It contains
ionized gas with a LINER type spectrum in the central 20". The ionized
gas rotates about the stellar major axis. We detect weak CO emission,
with an inferred H_2_ mass of ~2 x 10^7^ M_sun_. The profile is located
in the region of the 3-mm receiver affected by an interference and is
therefore considered as tentative. However, the J = 2-1 spectrum shows an
emission profile similar to that seen in the J = 1-0 line, making the
detection plausible. This galaxy was tentatively detected in the J = 2-1
line, by Lees et al. (1991).

9. 1994CAG1..B...0000S
Re:NGC 2768
S0_1/2_(6)
(I)
PH-719-B
April 4/5, 1953
103aO + GG1
20 min
The definite outer envelope of NGC 2768
surrounding an E6 bulge makes the S0 classification
certain. Very subtle dust patches on either
side of the major axis at the ends of the minor
axis (only hinted at in the print here) requires
the S0_1/2_ classification. The patches may be a
weak interior polar ring similar to the
well-developed dust rings perpendicular to the major
axis in the prolate cases of NGC 1947, NGC
2685, NGC 5128, NGC 5266, and NGC 5485,
all on panel 45.
The classification of E6 in the RC2, based
on a Mount Wilson 60-inch plate, is not supported
here.

10. 1994A&AS..105..481M
Re:NGC 2768
NGC 2768: This important object could be measured at large central
distances by combining plates and CCD frames (see Paper 1). The inner
isophotes are boxy, but become disky in the range l = 75-115 arcsec,
containing the effective isophote, while the axis-ratio goes through a
minimum. This galaxy is thus classified as diE. The kinematics suggest
however that it is not A fast oblate rotator (see Davies et al. 1983).

11. 1976RC2...C...0000d
Re:NGC 2768
Polarization:
Ap. J. (Letters), 179, L93, 1973.
HI 21cm:
upper limit:
A.J., 77, 568, 1972.

12. 1973UGC...C...0000N
Re:UGC 04821
E+6 (de Vaucouleurs)

13. 1964RC1...C...0000d
Re:NGC 2768
Very small, very bright center. Smooth nebulosity in lens:
1.4 arcmin x 0.5 arcmin and extended envelope.
An absorption patch noted by Hubble on a 60-inch plate of 1923 is a defect.
Lick 13 dimensions are for lens only.
One aberrant value of (B-V) (source C) rejected.
Magnitude:
Ap. J., 85, 325, 1937.
Photometry:
M.N.R.A.S., 96, 602, 1946.
Ap. J., 120, 439, 1954.

14. 1918PLicO..13....9C
Re:NGC 2768
A rather bright oval 1.4' x 0.8' in p.a. 95^deg^. Nucleus nearly stellar; a very
compact spiral, but spiral structure quite indistinct. 0 s.n.


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