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Notes for object NGC 3227

44 note(s) found in NED.


1. 2009ApJ...702.1127R
Re:NGC 3227
This active nucleus is usually classified as a Sy1.5. XMM-Newton observations
show short-term hard X-ray variability likely related to variation in the
intrinsic continuum emission (Gondoin et al. 2003). The clumpy models reproduce
the SED well, including the direct though extinguished AGN emission (using the
Calzetti et al. (2000) law), as in the case of NGC 4151. The resulting
histograms show broad Gaussian distributions of the {sigma}, N_0_, and {tau}_V_
parameters, with median values of 33^deg^ +/- ^20^_12_, 6 +/- ^5^_4_, and 116
+/- ^56^_55_, respectively. Low values of i (<48^deg^) are more probable than
others, and the q parameter results unconstrained. The optical depth calculated
using the fitted model parameters is A^LOS^_V_ < 210 mag. On the other hand, the
extinction that obscures the direct AGN emission is A_V_ = 2.7 +/- ^2.0^_1.5_
mag (not related with the torus). This value is intermediate among those
reported in the literature of A_V_ = 1.2-1.7 mag (Cohen 1983; Gonzalez-Del gado
& Perez 1997) and A_V_ = 4.5-4.9 mag (Mundell et al. 1995). The 10 {mu}m
silicate feature is practically absent from the fitted models ({tau}^app^_10
{mu}m_ = -0.1).

2. 2008MNRAS.386.2242H
Re:NGC 3227
NGC 3227. It has a asymmetric molecular nuclear ring with a diameter of ~3
arcsec (Schinnerer, Eckart & Tacconi 2000), the Sersic index (n= 1.1) of
the bulge is also disc-like (Gadotti 2008).

3. 2008MNRAS.386.2242H
Re:NGC 3227
NGC 3227 - The mass 2.0^+1.4^_-1.3_ x 10^7^ M_sun_ is a mean value of
the measurement using stellar kinematics [ (0.7-2.0) x 10^7^ M_sun_,
Davies et al. 2006] and gas kinematics [ 2.3^+1.1^_-0.5_ x 10^7^ M_sun_
(corrected for distance), Hicks & Malkan 2008], which is consistent with
the RM measurement [ (4.2 +- 2.1) x 107 M_sun_ , Peterson et al. 2004].
The stellar velocity dispersion is estimated by the author from the figs
6, 11 and 16 of Davies et al. (2006).

4. 2008MNRAS.386.2242H
Re:NGC 3227
NGC 3227. It has a asymmetric molecular nuclear ring with a diameter of ~3
arcsec (Schinnerer, Eckart & Tacconi 2000), the Sersic index (n= 1.1) of the
bulge is also disc-like (Gadotti 2008).

5. 2008MNRAS.386.2242H
Re:NGC 3227
NGC 3227 - The mass 2.0^+1.4^_-1.3_* 10^7^ M_{sun}_ is a mean value of the
measurement using stellar kinematics [(0.7-2.0) * 10^7^ M_{sun}_, Davies et
al. 2006] and gas kinematics [2.3^+1.1^_-0.5_*10^7^M_{sun}_ (corrected for
distance), Hicks & Malkan 2008], which is consistent with the RM measurement
[(4.2 +/- 2.1)*10^7^ M_{sun}_, Peterson et al. 2004]. The stellar velocity
dispersion is estimated by the author from the figs 6, 11 and 16 of Davies et
al. (2006).

6. 2007MNRAS.379.1249D
Re:NGC 3227
NGC 3227 is a well-studied barred galaxy, interacting with the elliptical galaxy
NGC 3326, and with an associated dwarf galaxy (Mundell et al. 2004). The
galactic disc has an inclination of 56{degree}, with a outer photometric
major-axis at a PA PA = 158{degrees} (Mundell et al. 1995a), coincident with the
major-axis of the stellar bar. It is hosting a type 1.5 Seyfert nucleus (Ho et
al. 1997). The central region has been mapped in ^12^CO(1-0) and ^12^CO(2-1) by
Schinnerer, Eckart & Tacconi (2000a), who detected molecular gas very close to
the nucleus (~13 pc). The inner kpc regions host several complex features: a
radio jet (PA ~ -10{degrees}; Mundell et al. 1995b), a conical NLR outflow at a
PA of about 15{degrees} (Mundell et al. 1995a), an H{alpha} outflow at PA ~
50{degree} (Arribas & Mediavilla 1994) and a molecular nuclear ring (Schinnerer
et al. 2000a).
Our SAURON stellar continuum map (Fig. 4a) presents an elongated structure
(PA = 153{degrees}), aligned with the stellar bar. The stellar velocity field is
regular (Fig. 4a), the major-axis being parallel to the galactic disc
orientation. Outside r > 5 arcsec, the stars rotate rigidly (isovelocity
contours parallel to each others). The stellar velocity dispersion rises towards
the centre, reaching 200 km s^-1^ in the inner 5 arcsec.
Fig. 4(a) presents [O III] and the narrow component of H{beta} emission
lines. The central broad component for the H{beta} line corresponding to nuclear
emission (BLR) has been removed. [O III] distribution is rather asymmetric,
elongated on the north side of the field and the H{beta} emission lines extend
from south-east to east. The [O III] and H{beta} velocity fields are similar:
they show strong deviations from axisymmetry with the PA of the major-axis
changing from ~30{degree} in the central regions to about 170{degree} close to
the stellar kinematic major-axis orientation. The velocity dispersions of both
H{beta} and [O III] rise towards the nucleus, reaching 310 km s^-1^ and 360 km
s^-1^, respectively, in the centre. Finally, the [O III]/H{beta} line ratio map
shows an elongated structure of high values (>7) along the global kinematic
major-axis (north-south).

7. 2007ApJ...671.1388D
Re:NGC 3227
A1.3. NGC 3227 An analysis similar to that for Circinus was performed on NGC
3227 by Davies et al. (2006), and the diagnostics given in Table 3 are taken
from this reference. In this case we were able to make estimates of and correct
for contributions of (1) the narrow-line region to Br{gamma} because there were
clear regions along the minor axis that had higher dispersion; (2) the AGN to
the radio continuum, by estimating the maximum contribution from an unresolved
source; and (3) the bulge stars to the stellar luminosity, by extrapolating the
radial profile of the bulge to the inner regions. The STARS models yielded the
result that in the nucleus, star formation began approximately 40 Myr ago and
must have already ceased. At the resolution of 0.085", the most compact
component of stellar continuum had a measured FWHM of 0.17", suggesting an
intrinsic size scale of ~12 pc. Young stars within 30 pc of the AGN (i.e., more
than just the most compact region) have a luminosity of ~3 * 10^9^ L_sun_, which
is ~20% of the entire galaxy.

8. 2007AJ....134..648M
Re:NGC 3227
NGC 3227 (Figs. 7.7, 8.1, 9.7, 20.7): This Sy1.5 galaxy shows a bright saturated
nucleus and an off-center bar of star-forming regions, which is misaligned with
the main galactic bar. This feature is probably caused by a close interaction
with the dwarf elliptical NGC 3226. There is a star-forming region 100 pc to the
north that is also visible in [O III] images (Schmitt & Kinney 1996). X-ray
variability from its nuclear source has also been reported (Gondoin 2004).

9. 2006ApJ...638..106W
Re:NGC 3227
This object is a nearby Seyfert galaxy interacting with a gas-poor companion. A
clear 3.3 micron polycyclic aromatic hydrocarbon (PAH) emission feature, which
is usually associated with star formation activity, was identified in its inner
60 pc (EW_3.3_ = 52 +/-10 A; Rodriguez-Ardila & Viegas 2003). These authors also
observed another two objects, Mrk 766 and 1H 1934-063, that are listed in our
sample. In Mrk 766, the PAH feature has been detected as well (EW_3.3_ = 40 +/-
11 A), while no evidence for the PAH feature has been observed in 1H 1934-063
(EW_3.3_ < 10 A). The position of 1H 1934-063 in the color-color diagram is
indicated by an open star. As a first inspection, both NGC 3227 and Mrk 766 have
much cooler {alpha}(60, 25) than does 1H 1934-063.

10. 2006A&A...457...61R
Re:NGC 3227
NGC 3227. Because of its proximity (15.6 Mpc), NGC 3227 is a well-known
and studied Seyfert 1/1.5 galaxy in virtually all wavelengths
intervals. It displays all the possible ingredients found in an AGN:
variability in its nucleus (both in the line and continuum Winge et al.
1995), a radio jet (Kukula et al. 1995), an ionization cone in [O III]
(Mundell et al. 1995), a circumnuclear starburst (Gonzalez Delgado et
al. 1997), strong X-ray emission (Reichart et al. 1985), an inner warp
molecular disk (Quillen et al. 1999). The NIR images of this galaxy
reveal an unresolved nuclear source in the K band and a nuclear stellar
cluster that is slightly resolved in the J and H bands, this cluster
contributes to about 40-65% of the total emission continuum (Schinnerer
et al. 2001). The NIR properties of this object have been studied,
among others, by Reunanen et al. (2003), Schinnerer et al. (2001) and
Quillen et al. (1999). Our spectrum shows a rich emission line spectrum
with strong broad permitted lines in He I and Pa{beta}. [S III] is the
brightest forbidden narrow line. [Fe III] 1.257, 1.644 microns are also
strong in the spectrum. High-ionization lines of [S VIII] 9912 Angstrom
and [Si VI] 1.963 microns, although weak, were detected. The continuum
is steep, decreasing towards longer wavelengths. It displays CO
absorption bands in H and K, as well as the Ca II triplet at the blue
edge of the spectrum.

11. 2005ApJ...627..674A
Re:NGC 3227
NGC 3227.This Seyfert 1.5 galaxy has the steepest radio spectral index in our
galaxy sample, with {alpha}^1.7^_5.0_ = -0.9 as measured by Mundell et al.
(1995) using the Multielement Radio-Linked Interferometer Network (MERLIN).
Their data show a resolved structure aligned at P.A. -10^deg^, with a flux
density of 8 mJy at 5 GHz. Although the 5 GHz peak flux density measured by
MERLIN was greater than 2 mJy beam^-1^, our 8.4 GHz measurements find no
detectable emission on VLBI scales. The 5 {sigma} upper limit to any compact
emission is 260 microJy beam^-1^. Our VLA measurements are severely handicapped
by brightness changes caused by u-v effects, and we do not include this object
in our short-term variability study.

12. 2004MNRAS.350..140S
Re:NGC 3227
2.2.5 NGC 3227 This nearby Seyfert 1.5 is known to have both a compact
(0.4 arcsec) double radio source in PA {approx}170deg, and
high-excitation line emission extending ~7 arcsec north-east (NE) of the
nucleus, in PA ~ 30deg (Mundell et al. 1995). It was included in the
pioneering study of Schmidt & Miller (1985), whose low-resolution
spectropolarimetry shows p({lambda}) rising from {approx}1 per cent at
6000{Angstrom} to {approx}3 per cent at 3500{Angstrom}, while the
position angle is constant at {theta}{approx} 135deg. Schmidt & Miller
also reported that the H{beta} line is polarized at the same level as
the continuum whereas the [O III]{lambda}{lamdba}4959, 5007 doublet has
a slightly lower polarization, but the same PA as the continuum. Our new
spectropolarimetry (Fig. 5) also shows an increase in the degree of
polarization to the blue, from {approx}0.5 per cent at 7000{Angstrom} to
1.5 per cent at 5000{Angstrom}, in good agreement with Schmidt &
Miller's results. However, the higher spectral resolution of our data
allows better measurements of the emission line polarization, and
reveals some differences. We confirm that the narrow lines are polarized
at a lower level than the continuum. Sharp dips in p({lambda}) are
associated with the narrow component of H{alpha} and [N II]{lambda}6583,
as well as the strong [O III]{lambda}{lamdba}4959, 5007 lines. We also
detect small changes in {theta}, showing that these lines are polarized
at a slightly different PA from that of the continuum. They are also
prominent in the polarized flux spectrum. The most important new result
is the clear peak in p({lambda}) associated with the broad wings of
H{alpha} (Schmidt & Miller's spectropolarimetry does not extend to
H{alpha}). There is some evidence for a similar feature in H{beta},
although with the lower signal-to-noise ratio at the blue end of the
spectrum it is harder to distinguish from the rising continuum
polarization. Except for the small changes associated with the narrow
lines and a small rotation (~10deg) over the broad H{alpha} line, the
polarization PA is constant across the spectrum with a value
{theta}{approx} 122deg. It is clear from our new data that the optical
polarization properties of NGC 3227 are consistent with polar
scattering. In this case, there is also a well-defined radio axis, but
the polarization PA is neither aligned with the radio PA, nor
perpendicular to it. However, it is nearly perpendicular to the symmetry
axis of the extended emission-line region. We will consider the
implications of these alignments in Section 5.3.

13. 2004ApJ...613..682P
Re:NGC 3227
NGC 3227. This AGN was the target of two separate optical campaigns, one
by the LAG consortium in 1990 (Salamanca et al. 1994) and one at CTIO in
1992 (Winge et al. 1995). The rms spectra formed from the LAG data were
recently presented by Onken et al. (2003). We completely reanalyzed the
CTIO data. The original reduced spectra were rescaled in flux using the
van Groningen & Wanders (1992) algorithm that has been used in most of
the International AGN Watch campaigns and in the Ohio State program, and
new continuum and H{beta} emission-line light curves were measured from
the rescaled spectra. While this resulted in some improvement in the
H{beta} lag determination and uncertainty, the rms spectrum was still
quite noisy because of the combination of a low amplitude of variability
and a relatively insensitive detector (see the notes on IC 4392A,below).

14. 2003ApJS..146..353M
Re:NGC 3227
NGC 3227 (C)
The nucleus in V is very saturated, although it is not so bright at H
that it overwhelms the circumnuclear region. While there is
considerable dust present, even down to small scales, it does not take
an obvious spiral form.

15. 2002ApJS..143...73E
Re:NGC 3227
NGC 3227.---SBab: Interacting pair with NGC 3226, with overlapping
disk isophotes. NGC 3227 is the system to the SE. Bright nuclear point
source, embedded in a bulge with a clear X-distortion (Whitmore & Bell
1988) in the inner isophotes. The outer bulge isophotes are
peanut-shaped. A bar threads the bulge, along its major axis. The P.A.
of the bulge and bar is in the direction of the SE system. There are
a number of star-forming knots on the SE side of the bar. Two broad,
smooth, diffuse spiral arms emerge from the ends of the bar and can be
traced for ~180deg.

16. 2002AJ....124..675C
Re:UGC 05620
Both nearby NVSS components are part of this extended radio source.
Seyfert 1.5.

17. 2001ApJS..136...61S
Re:NGC 3227
5.17. NGC 3227 (=Arp 94)
NGC 3227 is classified as Seyfert 1.5 and is interacting (see e.g.,
Mundell et al. 1995b) with NGC 3226, a dwarf elliptical companion.
Mundell et al. (1995a) obtained ground-based [O III] imaging showing an
extended (7" to the NE of the nucleus, P.A. ~ 30^deg^) structure
nonaligned with their radio map (6 and 18 cm) showing a 0.4" double
radio source at P.A. ~ -10^deg^ (the difference in position angles
between the radio and optical structures is ~40^deg^). Schmitt & Kinney
(1996) present an archival [O III] HST image made with a shorter exposure
time than that by Mundell et al. (1995a) showing a compact nucleus and
extended (0.9") emission (P.A. 15^deg^). Arribas & Mediavilla (1994)
present results of two-dimensional optical spectroscopic observations of
the inner kiloparsec of this galaxy showing both AGN and H II region-like
emission line properties. NGC 3227 shows strong spectral variability in
the optical (see Salamanca et al. 1994) and in X-ray (George et al. 1998).
A NICMOS image of Quillen et al. (1999) shows resolved H_2_ 1-0 S(1) line
emission which our data also reveal. The H_2_ emission is elongated in the
same way as the compact ^12^CO (1-0) millimeter interferometric map of
Schinnerer, Eckart, & Tacconi (2000), and our H_2_ peak and the CO peaks
(^12^CO (1-0) and ^12^CO (2-1)) are offset from the nuclear position,
though the H_2_ offset is only ~0.3", smaller than that observed in the
interferometric CO observations. Speckle images obtained by Weinberger,
Neugebauer, & Matthews (1998) in the H and K bands show an unresolved
point source at or near the diffraction limit of the Palomar 200 inch
telescope on top of an extended region of continuum emission (in agreement
with our broadband images) and also find that the colors of the nucleus
are consistent with hot dust emission, as also suggested by the spectra
shown in Figure 2.

18. 2001ApJS..133...77H
Re:NGC 3227
NGC 3227 (S1.5). - The core of NGC 3227 is resolved at <~1" resolution
(Condon 1980; van der Hulst et al. 1981; Ulvestad et al. 1981; Ulvestad &
Wilson 1984a; Hummel et al. 1987; Kukula et al. 1995), and at even higher
resolution it breaks up into a 0.4" double source at P.A. ~ 170^deg^
(Mundell et al. 1995; {DELTA}{theta} = 0.05").

19. 2001ApJ...550..261W
Re:NGC 3227
3.3.3. NGC 3227
The source flux changes by ~10% between the two ASCA pointings,
approximately 2 yr apart (Fig. 8c). No line variability is observed, but
there are only two time-averaged data sets to be compared. We note that
during a single observation the continuum changes by as much as a factor
of 2 within a few hours, so there may be interesting variability on
timescales that are comparable to Mrk 279. (We have not yet studied in
detail the short-timescale behavior of this spectrum.)

20. 2001A&A...378..370V
Re:NGC 3227
NGC 3226/7 pair: mapped in H I at the VLA (Mundell et al. 1995). No H I
was detected in NGC 3226, and NGC 3227 shows a complex H I distribution
and kinematics. About half the H I resides in a disk with a normal
rotation curve, the rest in two plumes extending 7' N and 16' S of the
system, and in an H I feature at the base of the N plume which may be a
gas-rich dwarf galaxy. As the plumes have a N-S orientation, the Nancay
beam will cover almost all of the H I emission, as the southernmost half
of the southern plume is relatively faint compared to the bulk of the
emission. Our Nancay integrated line flux (16.6 Jy km s^-1^) is consistent
with the Green Bank and Jodrell Bank data, while the Arecibo values are a
bit lower. The only significantly discrepant Arecibo value is the
6.8 Jy km s^-1^from Chamaraux et al. (1987). Our W_20_ profile width is
consistent with the other measurements, but our W_50_ value (103 km s^-1^)
is similar to the Green Bank measurement by Peterson (1979) only, the
5 other published values are ~350 km s^-1^ on average. NGC 3226 is an
E2:pec with a LINER spectrum, and NGC 3227 an SAB(s)pec with a Seyfert 1.5
spectrum.

21. 1999ApJ...527..696Q
Re:NGC 3227
NGC 3227 contains a bright nuclear point source which hampers our
ability to detect extended line emission. We attempted to subtract a
nuclear point source using a model point-spread function (PSF) created
by Tiny Tim4 (Krist et al.1998). However the PSF-subtracted narrowband
images did not produce a line emission map significantly better than
that using the images containing the nuclear point sources. Molecular
hydrogen emission elongated about P.A. ~100^deg^ (agreeing with that
observed by Fernandez et al. 1999) is detected in both PSF subtracted
and nonsubtracted line emission maps. The most straightforward
interpretation (also put forth by Fernandez et al. 1999) for the
extended H_2_ emission is that it lies in a 100 pc diameter "disk" with
a major axis P.A. ~100^deg^. This "disk" is not aligned with the
ionization cone observed in [O III] at P.A. ~30^deg^ or that of the
18 cm radio emission at P.A. ~ -10^deg^ (Mundell et al. 1995). The
position angle of the H_2_ emission also differs from that of the major
axis of the galaxy (P.A. ~155^deg^). There is evidence from the CO
velocity field that a warped molecular disk is present in this region
(Schinnerer et al. 1999). The color map shown in Figure 1 suggests that
extinction is large along the axis of the molecular hydrogen emission.

22. 1999ApJ...526L...9P
Re:NGC 3227
This is a Seyfert 1 galaxy for which Kukula et al. (1995) found that
the radio jet is along P.A. = -7^deg^. The parameters determined by
Mundell et al. (1995) using kinematical data are i = 56^deg^ and
{delta} = 15^deg^. Nandra et al. (1997) fitted the Fe K{alpha} line
profile with an inner accretion disk inclination (+/-{phi}) of
i_disk_ = 20^+10^_-10_ degrees. Using the rotation curve of this galaxy
and assuming that the spiral arms are trailing, we conclude that the
east side of the galaxy is the nearer side, so the jet is projected
against the nearer half of the galaxy. Using these values and equation
(3), we find that {beta} ~ 63^deg^. Notice that the i_disk_ value found
by Nandra et al. (1997) has a large uncertainty so that our results
should be taken with caution.

23. 1999ApJ...516...97N
Re:NGC 3227
NGC 3227 (Arp 94): RC3 lists major axis P.A._RC3_ = 155^deg^ and
log R_25_ = 0.17. We use the major axis P.A. and inclination obtained
from H I kinematic observations (Mundell et al. 1995).
P.A._RC3_-P.A._H I_ = 3 ^deg^.

24. 1999AJ....118.2331V
Re:NGC 3227
Only a single F606W PC image of NGC 3227 is available. Using the
absolute position of the SN Ia 1983U from the Sternberg SN catalog, we
find that the SN site is along a faint extension of a spiral arm, far
from the brighter stellar emission near the galaxy nucleus, and near
(but not in) the dust lanes.

25. 1998ApJS..114...73G
Re:NGC 3227
Section A4. NGC 3227
This Seyfert 1.2 galaxy was first detected in X-rays by Ariel V (Elvis et al.
1978). In our analysis of the data from an ASCA observation performed in 1993
May, we find model A(i) to provide an unsatisfactory description of the
spectra (Table 3). Fits satisfying our criteria for acceptability are
obtained if ~35% of the continuum escapes without suffering attenuation by
neutral material [model A(ii); Fig. 4]. However, yet superior fits are
obtained if the absorbing gas is assumed to be ionized [model B(i); Fig. 6].
The parameters of the ionized gas are fairly well constrained, with UX ~
10^-2^ and N_H, z_ ~ 4 x 10^21^ cm^-2^ consistent with the findings of Ptak
et al. (1994) and R97 (U^R97^_X_ ~ 0.02, N_H_, z ~ 4 x 10^21^ cm^-2^) in
their independent analysis of this ASCA observation.
.
We find that statistically there is no requirement for any of the underlying
continuum to escape without suffering attenuation by the ionized material or
for any significant emission from the ionized gas [models B(ii)-C(ii)]. In
all cases there is no requirement for additional absorption by neutral gas in
excess of N^gal^_H,0_. The derived photon index ({GAMMA} ~ 1.6) found for
NGC 3227, is flatter than for the majority of the sources (Fig. 2),
consistent with previous measurements by HEAO-1 (W95), Einstein (T91), EXOSAT
(TP89), Ginga (NP94), and ROSAT (Rush et al. 1996). However, it is important
to note that EXOSAT observations of NGC 3227 revealed significant spectral
variability on timescale as short as 10^4^ s, most likely as a result of
changes in absorption (TP89). Furthermore, such variability was also present
during the ASCA observation presented here (Ptak et al. 1994; Paper I). Thus,
it should be remembered that our results most likely represent the
time-averaged values. We note evidence was found for a Fe K-shell edge in the
7.1-8.9 keV in two Ginga observations of the source. NP94 found evidence for
absorption by ionized gas with N_H, z_ ~ 3 x 10^22^ cm^-2^, higher than that
observed here.

26. 1998ApJ...500..685P
Re:NGC 3227
2. NGC 3227.--NGC 3227 has a Seyfert 1.5 type nucleus, hosted by an SAB galaxy
interacting with the dwarf elliptical companion NGC 3226. This galaxy shows
large quantities of dust in its disk (Kotilainen & Ward 1997), as well as many
H II regions that are mostly located in the leading parts of the stellar bar.
The three components needed to fit the SED of NGC 3227 have temperatures of 16,
45, and 136 K, with widths of 6, 30, and 110 K, respectively. For this galaxy
the more prominent component is the cold 45 K component. This is very likely a
result of the many star-forming regions seen in the galaxy.

27. 1997MNRAS.286..513R
Re:NGC 3227
7.1.5 NGC 3227
The rapid spectral variability of this object has been discussed in Section
6.2.2. As with MCG-6-30-15, such variability strongly suggests a multizone warm
absorber.

28. 1997ApJS..112..391H
Re:NGC 3227
NGC 3227.--In order to quantitatively measure the extremely broad (FWZI~16,000
km s^-1^) H{alpha} line of this well-known Seyfert 1 nucleus, we carefully
removed the narrow-line contribution of the blend by scaling an accurate model
constructed from [S II] (Fig. 6b). It is difficult to tell whether all the
narrow lines have the same profile, but this is not crucial for the purposes of
measuring such a strong, broad H{alpha} line. Broad H{beta} and H{gamma} are
both very prominent. The broad lines in this object are known to be variable
(see, e.g., Winge et al. 1995); the spectrum shown here was taken on 1986 March
29 UT.

29. 1997ApJS..110..299M
Re:NGC 3227
Bar is visible in the K_S_image. The ellipticity and P.A. also suggest the
presence of a bar, although the fits do not trace the full length of the
bar. Unbarred in the RSA.

30. 1997ApJS..108..155G
Re:NGC 3227
This S1 galaxy shows a complex circumnuclear region with a starburst and
high-excitation gas presumably ionized from the active nucleus. In
H{alpha}, the emission extends 15" in the form of a shell-like structure
and an H II region at 500 pc SW from the nucleus (Fig. 11g). The [O III]
is elongated 8" to the north (Fig. 11g); aligned with an excess of the
continuum emission that Gonzalez Delgado & Perez (1996b) identify with a
stellar bar. The disk shows H II regions located mostly in the leading
edge of the stellar bar. As in NGC 7469, NGC 3227 has molecular gas in a
radius of 600 pc around the nucleus. Arribas & Mediavilla (1994) have
found that two kinematic components coexist in the north, one ionized by
the nucleus and the other by the circumnuclear starburst (see Gonzalez
Delgado & Perez 1996b).

31. 1997A&A...327..493R
Re:NGC 3227
NGC 3227 is an interacting system galaxy. Mirabel & Wilson (1984) observed this
galaxy in HI. The HI profile shows a prolonged plateau followed by a narrow
emission peak. Our CO profile is a lot smoother with two CO peaks, one at 1089
km/sec and the other at 1257 km/sec. Our two component CO profile is consistent
with the two intensity peaks in the interferometric observations of the same
galaxy by Meixner et a!. (1990). The HI peak was measured at 1146 km/sec, which
is the value we have used to center our CO observations. Heckman et al. (1978)
noted that their HI map made at Arecibo, shows evidence of interaction that
might disturb the HI kinematics. Therefore, it is possible that some of the gas
seen in their maps is related to the interaction between the two galaxies. The
HI FWZI is 575 km/sec, while our two peaks have a FWZI of 500 and 400 km/sec
for the strongest and the weakest respectively.

32. 1997A&A...319...33A
Re:NGC 3227
NGC 3227 Fig. 3 shows the rich X-ray field around NGC 3227. The strongest pair
is C=31.9 and 45.6. As Table 3 shows, the former is identified with a blue
galaxy which has BSO's at 43" and 83" distance from it, the latter is a
catalogued quasar of z=.828. The C=9.1 source is a possible double QSO.
The alignments include C=31.9, 9.0 and 45.6 and also C=9.1, 5.5, 3.6, 8.7 and
11.0, all BSO's plus one compact blue galaxy. The C=3.6 source has nearby
brighter BSO's -1.8s, -29" and +3.3s, -68" which could be worth checking.
It is often seen that pairs of X-ray sources are better aligned through smaller
companion galaxies which are active. In the present case NGC 3226, in contact
with NGC 3227 to the NW, is also a strong X-ray source (C=15.0). The source
C=11.0 and 9.1 are almost exactly aligned through this companion.
The strongest sources at C=31.9 and 45.6 along with the C=9.0 source define a
line just slightly rotated from N-S direction. It is interesting to note that
there is actually neutral hydrogen from the central galaxies extending about 8'
N and 19' S (Mundell et al. 1995). This line of hydrogen is quite straight and
both sides are 100 km s^-1^ higher redshift than the central NGC 3227. It would
seem more natural to suppose that this was an ejection track rather than tidal
tails.

33. 1996ApJ...463..498S
Re:NGC 3227
A4. NGC 3227
Mundell et al. (1995) detected extended [O III] emission in their ground-based
data of size 7" and PA 30^deg^. Their radio maps show a double source
separated by 0.4" with PA -10^deg^, not aligned to the [O III] emission. The
HST image presented here shows that this galaxy has a compact nucleus and
extended emission with PA 15^deg^. There is a second knot of emission ~0.25"
(18 pc) from the nucleus that may be related to the double-peaked radio source
found by Mundell et al. (1995) but that is extended with PA -10^deg^. The
bulk of the emission is extended by 0.9" (64 pc) with PA 15^deg^, or 1.4"
(100 pc) if we consider the faint emission extending farther north. However,
the HST image does not show the extended emission described by Mundell et al.
(1995) on ground-based observations, probably because of the very long
exposure time of Mundell et al.

34. 1995MNRAS.276.1262K
Re:NGC 3227
NGC 3227: (VV209) Type 2 (1.5). Host galaxy: SB multiple or interacting
(with nearby object NGC 3226) (CPG), SB at group centre (UGC). Radio: the
C-array image is marginally resolved. In the A-array map the object is
elongated in a north-south direction.

35. 1995ApJ...447..121W
Re:NGC 3227
NGC 3227.-We detect an Fe K feature in this galaxy. The measured Fe K
line EW is consistent with that seen by EXOSAT (Leighly et al. 1989) but
larger than that seen by Ginga (NP94). The upper limit on N_HFe_ is
consistent with Ginga (NP94).

36. 1994CAG1..B...0000S
Re:NGC 3227
Karachentsev #234 [with NGC 3226]
Sb(s)(tides)
PH-7983-S
Feb 1/2, 1981
103aO
12 min
The three images in this column have been
made from the same original plate printed to
different contrast to show (1) the tidal plumes,
one of which connects the galaxies in the top two
prints, and (2) the lack of perturbation of the
central region of NGC 3227 (Sb) even in the
presence of what evidently is a strong encounter.
The separation of the components is 2.2'.
The redshifts are v_o(3226) = 1260 km/s and
v_o(3227) = 1102 km/s, giving a redshift
distance of 23.6 Mpc (H = 50). The projected linear
separation is small at 15 kpc. The pair is number
234 in Karachentsev's catalog of pairs.
The pair is important for understanding the
origin of S0 galaxies. (Are they generic to the
classification sequence or a result of environmental
effects on former spirals?) Other examples of
pairs in this atlas where a large classification
difference exists and where the evidence is good
that the pair is at the same distance include NGC
274/275 (panel 52), NGC 470/474 (panels 84,
189), and NGC 1596/1602 (panels 51, 328).

37. 1994CAG1..B...0000S
Re:NGC 3227
Karachentsev 234 [with NGC 3226]
Sb(s)(tides)
PH-7983-S
Feb 1/2, 1981
103aO
12 min
This pair, in an obvious encounter, has been
described in the E/S0 section. The redshifts are
the same to within about 150 km/s. The
noteworthy feature is the very large difference in
the individual morphological types: a prototypical
S0 is paired with a generally normal Sb.
Tidal plumes from NGC 3227 (the Sb)
appear to be present.

38. 1993A&AS...97..887B
Re:NGC 3227
NGC 3227 is a well-known Seyfert galaxy interacting with NGC 3226. It has
been observed with a large beam in CO(1-0) by Blitz et al. (1986) and at
very high resolution with the OVRO interferometer by Meixner et al.
(1990).

39. 1991ApJ...381...85T
Re:NGC 3227
This very low luminosity Seyfert 1.2 galaxy has an unusually flat slope in
the SSS+MPC data (Table 2). This flat slope was also seen 4 years later in all
of the five observations of that source obtained with EXOSAT. During those
EXOSAT observations large and rapid (10,000 s time scale) variations were
observed, indicating either a rapidly variable absorber or a highly
variable soft excess emission component. Similarly to NGC 2992, the addition
of a soft excess or a complex partial absorber provides a significant
improvement over the simple power-law model fit to these data with 79% of
the source covered by a column of 2.18 (1.31-4.29) x 10^22^ cm^-2^
(see section 2.3.2).

40. 1976RC2...C...0000d
Re:NGC 3227
= Holm 187a
= Kara[72] 234b
Interacting pair with NGC 3226; connected with very faint outer extensions.
Part of Arp 094 = VV 209
Type 2 Seyfert nucleus; B(nucleus) = 15.0, B_T(excluding nucleus) = 11.58.
Diameter of nucleus:
A.J., 73, S175, 1968.
Photograph:
Ap. J., 154, 431, 1968.
Astr. Ap., 15, 110, 1971.
Publ. Dept. Astr. Univ. Texas, II, 2, No. 7, 1968.
Photometry:
A.J., 73, 858, 1968.
Photometry (UBV):
A.J., 73, 866, 1968.
Sov. A.J., 17, 169, 1973.
M.N.R.A.S., 169, 357, 1974.
Att... Conv. Sci. Osserv. Cima Ekar, Padova-Asiago, 101, 1973.
= Cont. Asiago No. 300bis.
Photometry: (B(pg) Variability)
M.N.R.A.S., 167, 1P, 1974.
Photometry: (I.R.: 1 to 22 microns)
A.J., 73, 866, 870, 1968.
Ap. J. (Letters), 159, L165, 1970.
Ap. J. (Letters), 161, L203, 1970.
Ap. J. (Letters), 176, L95, 1972.
M.N.R.A.S., 169, 357, 1974.
Sov. A.J., 12, 184, 1968.
Spectrum:
A.J., 73, 861, 1968.
Ap. J., 154, 431, 1968.
Ap. J., 192, 581, 1974.
Spectrophotometry:
Ap. J. (Letters), 154, L53, 1968.
Ap. J., 162, 743, 1970.
Ap. J., 164, 1, 1971.
Sov. A.J., 11, 767, 1968.
Ast. Tsirk. No. 467, 1968.
Ast. Tsirk. No. 663, 1971.
IAU Symp. No. 29, 83, 1968.
"Nuclei of Galaxies", 151, 1971.
Polarization:
Ast. Tsirk. No. 454, 1967.
Astrofizika, 4, 409, 1968.
Astrofizika, 7, 417, 1971.
Rotation Curve and Mass Determination:
A.J., 73, 861, 1968.
Ap. J., 154, 431, 1968.
HII Regions:
Bull. A.A.S., 6, 343, 1974.
HI 21cm:
Astr. Ap., 10, 198, 1971.
IAU Symp. No. 44, 267, 1972.
Radio Observations:
Austral. J. Phys., 19, 565, 1966.
A.J., 73, 876, 1968.
Astr. Ap., 15, 110, 1971.
Astr. Ap., 33, 351, 1974.
M.N.R.A.S., 167, 251, 1974 (with NGC 3226).

41. 1973UGC...C...0000N
Re:UGC 05620
VV 209a, Arp 94
See UGC 05617
SAB(s)a pec (de Vaucouleurs)
Blue diameter includes a very faint envelope surrounding both systems

42. 1964RC1...C...0000d
Re:NGC 3227
= Holm 187a
Very small, extremely bright nucleus. Bright, complex lens: 2.25 arcmin x
1.25 arcmin, with dark markings. 2 main smooth arms, one touching NGC 3226;
slight distortion?
Interacting pair with NGC 3226 at 2.2 arcmin.
Lund 6 dimensions are for the lens only.

43. 1959VV....C...0000V
Re:VV 209a
= NGC 3227
F3
V = +1,006 km/sec.
Core spectrum has broad emission
(Seyfert, K., Ap.J., 97, 145, 1943).
On the photograph the large external shocked regions
of VV 209a cannot be seen.

44. 1918PLicO..13....9C
Re:NGC 3227
Vol. VIII, Plate 24. The bright stellar nuclei of this interesting pair are 138"
apart in p.a. 159^deg^. Two nebulae close together, rather than a double nebula.
3226 is bright, nearly round, about 1' in diameter; no spiral structure
discernible. 3227 is 3' x 1.2' in p.a. 155^deg^, a patchy, compact spiral
without clearly marked whorls. 25 s.n.


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