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Notes for object NGC 2655

14 note(s) found in NED.


1. 2007MNRAS.379.1249D
Re:NGC 2655
NGC 2655 is an early-type spiral galaxy, hosting a Seyfert 2 nucleus. Optical
and radio spectroscopic data exhibit off-plane gas in the central part (Erwin &
Sparke 2003), and a dusty polar ring seen in H{alpha} (Keel & Hummel 1988). This
galaxy is interacting with its companion NGC 2715 and presents remnant
signatures of a past merger (Huchtmeier & Richter 1982).
The stellar continuum map (Fig. 4b) shows an elongated feature, along the
east-west direction, which corresponds well with the PA of the line of maximum
stellar velocity. The stellar velocity field (Fig. 4b) is remarkably regular,
with a PA around 90{degrees}. The velocity dispersion map shows a drop in the
inner 3 arcsec.
H{beta} and [O III] emission-line distribution and kinematics are similar
(Figs 4b and B1). The emission lines are very bright in the inner 5 arcsec. Away
from the centre, the distribution maps show a bright knot to the south-east
side, 15 arcsec away from the nucleus, and a lane at 10 arcsec on the west side;
both features have been reported by Keel & Hummel (1988). The south-east knot
corresponds to high [O III]/H{beta} ratio values (~4) similar to those observed
in the nuclear region. This feature could be driven by the radio jet (Keel &
Hummel 1988). The emission-line ratio is smaller in the west lane (around 2-3).
The emission-line velocity fields show strong departures from axisymmetry, with
an S-shaped zero velocity curve, the kinematic major-axis having a PA that
changes from ~90{degree} in the inner 5 arcsec to near 180{degrees} in the outer
parts. As hinted by Sil'chenko & Afanasiev (2004), the ionized gas rotates
together with the stars in the inner 5 arcsec, but follows the dust polar ring
at radii >5 - 6 arcsec, rotating perpendicularly to the galactic plane. [O III]
and H{beta} velocity dispersion maps show the same features: a rise in the inner
5 arcsec (~220 km s^-1^) and in the western feature (305 km s^-1^), and a
roughly constant value outside (between 100 and 150 km s^-1^).

2. 2005A&A...442..137N
Re:UGC 04637
UGC 4637 (NGC 2655) is a nearby Seyfert 2 galaxy whose nuclear regions show
complex structure, both in high-resolution radio continuum observations as in
optical emission lines (Keel & Hummel 1988). These authors attribute the
complexity of the central parts to a recent interaction or merger event. This
interpretation seems to be confirmed by the large-scale structure of the neutral
gas seen in our observations. The H I is clearly disturbed, with a large
extension to the northwest; the gas does seem to have a general sense of
rotation, but it is clearly not on regular circular orbits. The optical image of
this galaxy shows some distinct loops and shells, further confirming the
hypothesis of a recent interaction.

3. 2002ApJS..139....1T
Re:NGC 2655
NGC 2655 (S2).-The ASCA spectrum of this Seyfert 2 galaxy clearly shows
the presence of a heavily absorbed component and an additional soft
component. A RS + power-law model fit gave a negative photon index.
Although such a very flat spectral slope is expected from "cold"
reflection, the lack of a strong Fe K fluorescent line rules out this
possibility. Therefore, we tried three alternative models: a partially
covered power-law model, a double power-law model, and a RS + partially
covered power-law model. The best-fit photon index in the partially
covering model ({GAMMA} = 2.6) is steeper than the canonical slope of
Seyfert galaxies. This slope is primarily determined by the soft energy
band, which has better photon statistics, and suggests that there
exists a softer component in addition to a hard power law from the
AGN. If we adopt a double power-law model, the photon index of the soft
component becomes {GAMMA} = 2.4, where we fixed the photon index of the hard
component at {GAMMA} = 2.0. In this model, the absorption column density for
the hard component is N_H_ = 4.0 x 10^23^ cm^-2^ . Finally, we tried to
add a RS component to a partial covering model. We assumed a temperature
of kT = 0.65 keV and an abundance of 0.1 solar since these parameters
were not well constrained. The absorption column densities for the RS
component and the less absorbed power law were assumed to be equal to
the Galactic value. The model improved by {DELTA}{chi}^2^ = -16.3 for
one additional parameter (normalization of the RS component) compared
to a partial covering model. The best-fit photon index and absorption
column are {GAMMA} = 1.26^+0.57^_-0.69_ and N_H_ = 4.5^+2.0^_-1.4_
x 10^23^ cm^-2^.

4. 2001ApJS..133...77H
Re:NGC 2655
NGC 2655 (S2). - Keel & Hummel (1988) have reviewed the radio properties
of NGC 2655. They noticed that apart from the central core, which had
previously been studied by van der Hulst et al. (1981) and Hummel,
van der Hulst, & Dickey (1984), there exists a jetlike feature located ~15"
(1.8 kpc) to the southeast. This patch of radio emission is evidently
associated with an optical emission-line region, which could plausibly be
powered by the radio plasma. Our data reveal an additional component,
visible in the full-resolution and tapered 20 cm maps, on the opposite side
of the nucleus. The new northwestern component, located approximately 40"
(4.7 kpc) to the northwest at P.A. ~ 110^deg^, is weaker and more extended
than the southeastern component. The flux densities from the tapered 20 cm
map are S_20_(SE) = 8.0 mJy and S_20_(NW) = 3.8 mJy; the northwestern
component is not detected at 6 cm. We believe that the northwestern
component is real. Our tapered maps at both frequencies (see bottom right
panel of Fig. 4c) also show a "tongue" of emission extending from the
central core toward the northwestern component, strongly suggestive of an
ejection origin for the latter. The nucleus was not detected in the VLBI
experiment of Hummel et al. (1982). We detected weak linearly polarized
emission in our data. The signal is most readily seen in naturally weighted
maps tapered to {DELTA}{theta} = 2.5" (Fig. 16c). At 6 cm, the signal is
roughly equally divided between the core (S_pol,6_^I^ = 0.70 mJy) and the
southeastern feature (S_pol,6_^I^ = 0.55 mJy). The core polarization is
less than 0.2% of the total-intensity peak, but it appears that there may
be a significant signal in the polarization somewhat off the location of
that peak. The emission at 20 cm is much less well defined; nevertheless,
there do appear to be significant clumps of emission closely associated
with the jetlike extensions in the total-intensity image. The individual
clumps have peak flux densities S_pol,20_^P^ ~ 0.25 mJy beam^-1^,
approximately 10 times the rms in the map.

5. 2001A&A...368...16M
Re:NGC 2655
6. NGC 2655 = Arp 225 is an Sa galaxy which shows traces of a strong
interaction or merger event: faint outer stellar loops, extended
HI-envelope (Huchtmeier & Richter 1982). The bulge in NGC 2655 is
especially large (Table 4). The central dust-structure (Erwin et al. 1996)
is probably the reason for the disturbed fit residuum there.

6. 2000ApJ...542..186N
Re:NGC 2655
NGC 2655.-Comprehensive radio continuum and optical emission-line
imaging, as well as optical spectra, are presented by Keel & Hummel
(1988). Their VLA 6 cm map shows a roughly east-west symmetric extension
at 0.5" resolution (with a peak flux density of 36 mJy beam^-1^ from a
component with half-power size 0.4" x 0.5"). Combining this peak flux
density with our 2 cm peak flux densities of 6 and 13.4 mJy beam^-1^ at
resolutions of 0.15" and 5", respectively, results in a nonsimultaneous
spectral index, {alpha}_2_^6^ = -0.7 to -1.6, for the radio emission
within 0.5" of the nucleus. Keel & Hummel(1988) find S_{nu}_ is
proportional to {nu}^-0.67^ for the nucleus, from 4" resolution
nonsimultaneous VLA maps at 6 and 20 cm. They also find a secondary 6 cm
source in P.A. 117^deg^, with a diffuse bridge of radio emission
joining it to the nuclear component. The morphology, kinematics, and
line ratios of the surrounding emission-line gas suggest that this
secondary 6 cm source and bridge are related to nuclear ejecta (Keel &
Hummel 1988). Clearly, most of the radio emission in this object is
extended, and if the emission from the unresolved radio nucleus is
related to an accreting black hole, then its steep radio spectrum
suggests that it is more likely that the emission is from
synchrotron-emitting jets rather than from a compact radio core. The
host galaxy P.A. is not defined for this galaxy in the Uppsala General
Catalogue of Galaxies (Nilson 1973, hereafter UGC) or the Third
Reference Catalogue of Bright Galaxies (de Vaucouleurs et al. 1991,
hereafter RC3), as the galaxy is nearly round.

7. 1998ApJ...496..133B
Re:NGC 2655
NGC 2655.--Dust lanes cross the nuclear region of this Seyfert 2 galaxy. The
true nucleus may be heavily obscured.

8. 1997ApJS..112..391H
Re:NGC 2655
NGC 2655.--The [S II] lines yield an excellent model for the narrow lines, and
a broad H{alpha} component is suggested by the decomposition shown in Figure
8f. However, the result seems to be highly dependent on the choice of template
model used in the starlight subtraction, and we consider the detection to be
questionable.

9. 1996A&AS..117..343K
Re:NGC 2655
An 0849+78 is located at the extension of an outer spiral arm of NGC 2655 and
seems to be connected to it by a very faint bridge. Its isophotes are of
regular shape; a faint elongated nucleus is marginally visible. The light
profile is probably non-exponential, but its outer part is poorly determined
due to the uncertainties in background subtraction. The HI observations show
that An 0849+78 is confused by NGC 2655, at V_h_ = 1400 km/s. To calculate the
absolute characteristics we use for An 0849+78 the distance of NGC 2655. If
An 0849+78 is a bound (dwarf spheroidal) companion of NCC 2655, its survival in
the gravitational field of the bright galaxy is problematic. New multicolour
photometry and HI observations are needed.

10. 1994CAG1..B...0000S
Re:NGC 2655
Sa pec
(E,L,I)
PH-7928-S
Nov 7/8, 1980
103aO
12 min
NGC 2655 has smooth, tightly wound outer
arms, of the multiple-armed type, and dust near
the center. The fine pattern of the dust in
silhouette against the bulge is seen in the insert
print.

11. 1976RC2...C...0000d
Re:NGC 2655
= Arp 225.
Spectrophotometry:
Astr. Ap., 19, 405, 1972.
Polarization:
Ap. J. (Letters), 179, L93, 1973.
Radio Observations:
A.J., 75, 523, 1970.

12. 1973UGC...C...0000N
Re:UGC 04637
Arp 225
SAB(s)0/a (de Vaucouleurs)
In Arp's class "galaxies with amorphous arms"
"Very faint diffuse outer arms, absorption one side of nucleus" (Arp)
"Very bright, very large nucleus with asymmetric dark matter in lens (?)
1.9 x 1.4, very faint smooth outer whorls" (de Vaucouleurs)

13. 1964RC1...C...0000d
Re:NGC 2655
Very bright, very large nucleus with asymmetric dark material in lens (?):
1.9 arcmin x 1.4 arcmin. Very faint smooth outer whorls, center similar
to NGC 1316. Whole object similar to IC 5227.
See also M.N.R.A.S., 74, 239, 1914.
Yerkes type E4p (Morgan, 1958) is an error, probably refers to nucleus only.
Heidelberg Veroff. Vol. 9, 1926 dimensions for bright part only.
Magnitude:
Ap. J., 82, 62, 1935.
Ap. J., 85, 325, 1937.

14. 1918PLicO..13....9C
Re:NGC 2655
Slightly oval; exceedingly bright at center. The main portion is about 1' long;
outside are narrow, very faint spiral whorls; probably 4' in extreme diameter.
Curious small "hole" on s. side, close to nucleus. 28 s.n.


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