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Notes for object NGC 4438

20 note(s) found in NED.


1. 2007ApJS..173..538T
Re:NGC 4438
NGC 4438 (Fig. 16.22).-This SA(s)0/a pec: LINER galaxy is interacting with NGC
4435 as they cross the center of the Virgo Cluster at high speed (Vollmer et al.
2005). The high-speed collision is discussed by Kenney et al. (1995). GALEX
observations analyzed by Boselli et al. (2005) show the presence of very recent
star formation in a tidal tail extending to the northwest of the galaxy; this
feature was undetected at other wavelengths (including R down to 27.8 mag
arcsec^-2^ via Subaru). The UV-visible-NIR SED fitting of Boselli et al.
suggests that the burst of star formation is notably younger than the dynamical
age of the NGC 4438/NGC 4435 interaction. SDSS imagery highlights a large dust
concentration on the west side of NGC 4438. It is interesting to note that the H
I streamer of nearby NGC 4388 (Oosterloo & van Gorkom 2005) points very near to
NGC 4438's northwest XUV feature, with similar orientation.

2. 2006MNRAS.366..812C
Re:NGC 4438
Notice the off-plane filamentary morphology of the ionized gas to the West and
South of the galaxy disc, which was already seen in Kenney et al. (1995) and
Kenney & Yale (2002). No H I was detected in the disc (Cayatte et al. 1990). The
ionized gas is the best tracer of the complex morphology and kinematics of the
galaxy, which is presented in detail in Chemin et al. (2005).

3. 2006ApJ...647..140F
Re:NGC 4438
This galaxy (L1, S0/a) has only one point source, which is close to the center
but not exactly centered (within 2 {sigma}). It has a hard X-ray spectrum and is
embedded in soft diffuse emission with an elongated morphology. The spectrum of
the central source is well fitted by a thermal plasma model or a plasma
component plus a power law with a total luminosity of L_0.5-10 keV_ ~ 7.7 x
10^39^ ergs s^-1^. Since the source is deeply embedded in diffuse emission, it
is possible that it is an AGN. This source is weakly detected at 1.49 GHz with a
flux of 116 mJy (Condon 1987), which gives log R_X_ < -1.2, i.e., it can be
radio-loud. Also a broad H{alpha} line was detected (Ho et al. 1997c), which
supports the AGN hypothesis. An amorphous patch about 5" in size was detected in
the UV (Maoz et al. 1996), which was interpreted as a superbubble and might be
associated with the extended patch of diffuse emission seen in the X-ray.
However, age estimates of the stellar population indicate that an old population
dominates the optical starlight spectrum in the bulge (Cid Fernandes et al.
2004, 2005; Bonatto et al. 2000). We estimated the X-ray luminosity from the
central 2.5" radius region to be L_2-10 keV_ = 1.4 x 10^39^ ergs s^-1^ and the
luminosity of the AGN to be L_2-10 keV_ = 1.4 x 10^39^ ergs s^-1^ (obtained by
integrating the power-law component). Thus, the hard X-ray luminosity of this
LINER is primarily powered by the LLAGN. We note that this is the only LINER
whose dominant X-ray source luminosity changes depending on what band we
consider. The AGN dominates in the 2-10 keV band, while the plasma emission
dominates in the 0.5-10 keV band.

4. 2006A&A...460...45G
Re:NGC 4438
NGC 4438 (UGC 7574, Arp 120B). No nuclear point source was detected in our hard
X-ray band images (Fig. 5). The results from 25 ks Chandra ACIS-S observations
of this galaxy are presented in Machacek et al. (2004) who suggest the presence
of an AGN, based on the steep spectral index and the location of the hard
emission at the center of the galaxy, in contrast to our morphological
classification. The spectrum of the central 5" is claimed to be best-fitted by a
combination of an absorbed power law (with N_H_ = 2.9 x 10^22^ cm^-2^ and a
fixed {GAMMA} = 2.0) and a MEKAL 0.58 keV thermal component, providing L(2-10
keV) = 2.5 x 10^39^ erg s^-1^. Nevertheless, Satyapal et al. (2005) class this
galaxy as an non AGN-LINER based on its ACIS Chandra image, in agreement with
our classification, with kT = 0.77 keV and N_H_ =1.2 x 10^21^cm^-2^, consistent
with ours within the errors, but {GAMMA}=1.19.

5. 2004A&A...418..393S
Re:NGC 4438
NGC 4438 This galaxy, with a large bulge, is tidally distorted by a
companion just North of the frame. Gavazzi et al. (2000) fit a pure
r^1/4^ law to this galaxy, suggesting that its morphology is of an
earlier type than Sa.

6. 2002ApJS..139....1T
Re:NGC 4438
NGC 4438 (L1.9).-The LINER 1.9 nucleus of this galaxy is a very weak
X-ray source. The image in the 2-b keV band is consistent with the PSF,
while the 0.5-2 keV image is clearly extended. The ROSAT HRI image is
also extended (Halderson et al. 2001). The L_X_/L_H_{alpha} ratio
(0.8) is too low to account for the optical line emission, unless the
nucleus is heavily obscured at energies above 2 keV.

7. 2001AJ....121..710S
Re:NGC 4438
4.2. NGC 2782 and NGC 4438
At the other extreme from the NGC 7714/5 bridge in terms of CO
brightness is the eastern tail of NGC 2782 and the extra-disk gas
cloud near NGC 4438, with low L_H{alpha}_/M_H_2__ ratios compared to
the other features (see Fig. 4). These features have strong CO
emission, but little on-going star formation (Combes et al. 1988;
Kenney et al. 1995; Smith et al. 1999). None of the features in our
new sample are as rich in CO as the NGC 2782 and NGC 4438 features.
As discussed at length in Smith et al. (1999), the gas in these
features may be metal-rich material removed from the interiors of
their disks by near head-on collisions, leading to high CO fluxes.
Star formation may be inhibited in these features because of the
collision (Smith et al. 1999). Gas clouds pushed out of a galactic
disk by a high-velocity collision may compress and then adiabatically
expand, reducing their self-gravity. This may decrease the rate of
star formation and therefore the L_H{alpha}_/M_H_2__ ratio.

8. 2001A&A...378...51B
Re:NGC 4438
NGC 4438: In this HI poor galaxy near the center of the Virgo cluster
Combes et al. (1988) detected large quantities of molecular gas
significantly out of the plane of the spiral disk. They suggest the
material was torn out of the disk in molecular form, along with some
stars, through an interaction with nearby NGC 4435. Little HI is present
so HI - H_2_ conversion appears very unlikely.

9. 2000A&A...355...99B
Re:NGC 4438
G N4438: This group contains only the galaxies ESO 383-G35, a very
elongated lenticular galaxy in a cluster, and NGC 4438, which is in pair
with NGC 4435 in the Virgo cluster, probably being disrupted by M 87
(Rauscher 1995); optical and near-IR integrated spectroscopy suggests
that NGC 4438 might contain a low-luminosity LINER nucleus
(Bonatto et al. 1989) which is further confirmed by the near-IR
photometry by Jungwiert et al (1997).
Although the IUE spectrum of G N4438 has a low (S/N), the presence of
a bulge population can be clearly seen in Fig. 1. In fact, the
population synthesis of G N4438 shows that the old bulge population is
the dominant flux contributor (~ 55%) to its spectrum, with indications
of a series of important bursts distributed in age among the younger
populations (Table 4). Despite the low (S/N), a few conspicuous emission
lines can be seen in the spectrum of G N4438: C IV {lambda}1549,
He II {lambda}1640, C III]{lambda}1908 and C II]{lambda}2325-2329. They
might be related to the presence of a LINER nucleus. The synthesis of
G N4438 is shown in Fig. 8.

10. 1997ApJS..112..391H
Re:NGC 4438
NGC 4438.--With a strength of only 9% of the total H{alpha}+[N II] blend, the
broad H{alpha} component in NGC 4438 is among the weakest of our probable
detections. The high S/N of the starlight-subtracted spectrum allowed us to
construct an accurate profile model from [S II] that matched well the profiles
of the other narrow lines. Very faint residual wings were evident on both sides
of [N II] even after the narrow lines were removed, and the best fit was
achieved with the addition of a broad Gaussian with FWHM~2050 km s^-1^ (Fig.
12e).

11. 1997A&AS..125..479J
Re:NGC 4438
NGC 4438 (SA0/a(pec)/Sey 3, 1"~86 pc, I=35.1^deg^)
This galaxy (Arp 120), possessing a Seyfert nucleus, is interacting with a
close companion NGC 4435 in the Virgo cluster Its nuclear regions might be
perturbed by infalling gas (e.g. Combes et al. 1988; Kenney et al. 1995). Its
inner maximum in ellipticity could reflect either a tidally deformed bulge or a
nuclear bar.

12. 1995AJ....109.1608R
Re:NGC 4438
The SA(s)0 peculiar galaxy NGC 4438 is likely being disrupted by M87.
In Fig. 1 it is object 7. It is only 58 arcmin from M87. There are
extensive, strong dust lanes that have been dragged out of the galactic
plane so that they cross the bulge. The B image displays long tidal tails
at the ends of the disk. Miller (1986) has produced similar tails in N-
body simulations of a disk galaxy interacting with a cluster potential in
a "flyby" near the core, and points out the strong similarity to NGC
4438. There is a large area of gas and dust to the northwest of the
galaxy that has evidently been dragged far from the galactic plane, or
stripped away entirely by ram pressure.
Kotanyi et al. (1983) imaged the galaxy with the High Resolution Imager
(HRI) on the Einstein Observatory. They found a compact, low luminosity
L_x_ = 1.5 x 10^39^ erg s^-1^ (0.1-2 keV) source at the core, and
extended emission L_x_ = 3 x 10^39^ erg s^-1^ situated NW of the galaxy.
They note that nonaxisymmetric x-ray emission such as this is not common,
and present a number of mechanisms by which interaction with M87 could
produce heating of the x-ray emitting gas.
Based on optical images, Kotanyi et al. (1983) suggest that the
central bulge may be tidally disturbed. However, the lack of strong K band
isophotal twisting argues against this hypothesis.

13. 1994CAG1..B...0000S
Re:NGC 4438
VCC 1043
Sb?(tides)
CD-743-S
Feb 3/4, 1979
103aO + Wr2c
60 min
The galaxy seen below and to the right of
NGC 4435 is NGC 4438, whose outer disk is
highly disrupted. From the form of the shreds
that apparently have been torn away from the
disk of NGC 4438, the supposition would be that
a tidal interaction is occurring. However, the
redshifts are very different, at v_o(4435) = 753
km/s and v_o(4438) = -115 km/s, showing
either that the peculiar morphology of NGC
4438 is not due to tides or that the encounter is
one of exceptionally high velocity.
The angular separation of the pair is 4.4',
which is a projected linear separation of 28 kpc
using a Virgo Cluster core distance of 21.9 Mpc
(m - M = 31.7). The disturbed nature of the dust
lanes in the center of NGC 4438 (seen in the
insert) and the dust patches and large warp to the
luminous plane on the side closest to NGC 4435
are the circumstantial evidence that an interaction
is occurring. The very high velocity difference
of 868 km/s suggests a hyperbolic encounter.

14. 1994CAG1..B...0000S
Re:NGC 4438
VCC 1043
Pair [with NGC 4435]
Sb?(tides)
CD-743-S
Feb 3/4, 1979
103aO + Wr2c
60 min
NGC 4438 has a set of smooth luminous
plumes that may or may not define a highly
distorted plane. If so, the plane is disturbed and
the type is Sb(tides) from the existence of a plane
and the large central bulge. The presence of the
dust patches asymmetrically placed across the
image suggests that a plane exists and that the
form is not simply a bulge with tidal plumes.
Tidal distortion (Toomre and Toomre 1972)
caused by a close encounter is suggested by the
morphology. The obvious candidate for the
perturber is NGC 4435 [SB0(7)] at a separation of
only 4.3', also seen on the print here. However,
two points militate against a tidal perturbation:
(1) NGC 4435 shows no evidence of tidal effects,
and (2) the redshifts of the two galaxies are
widely different. The redshifts are v_o(4435) =
753 km/s and v_o(4438) = -115 km/s. An
encounter velocity as high as 868 km/s may not
produce strong tidal effects because the event is
too rapid.
The second-closest large galaxy to this pair
is NGC 4406 (S0/E3; panel 27), at a separation
of 18', whose redshift is v_o = 367 km/s. Its
morphology is as undisturbed as that of NGC 4435.
A possible explanation of the morphology of
NGC 4438 is that a merger is in progress having
nothing to do with NGC 4435, and that the
merged parents are not individually visible now.
Very short exposures of NGC 4438 show no sign
of two components; only a single nucleus exists at
the center of the bulge.
A prototype dE,N nucleated dwarf elliptical
is to the right of the major axis of NGC 4438 in
the print here, very close to the bulge. It is not
listed in the VCC probably because of its close
proximity to the main body of NGC 4438 where
it evidently was missed in the Virgo Cluster
Survey (Binggeli, Sandage, and Tammann 1985).

15. 1993A&AS...97..887B
Re:NGC 4438
NGC 4435/4438 are separated by about 5' (13 kpc). NGC 4438 has strong CO
emission (Combes et al. 1988) but we did not detect NGC 4435 in CO.

16. 1985ApJS...57..643D
Re:VV 188
Strongly distorted spiral with a small S0 companion.

17. 1976RC2...C...0000d
Re:NGC 4438
= Arp 120
= VV 188
= Holm 409a
Interacting pair with NGC 4435 at 4.3 arcmin
Photograph:
A.J., 79, 671, 1974.
Photometry:
Astrofizika, 2, 53, 1966.
IAU Symp. No.29, p.398, 1968.
Bol. A. A. Argentina, No. 16, 17, 1971.
Isodensitometry:
Ap. J. Suppl., 26, No. 230, 1973.
A.J., 79, 671, 1971.
Spectrophotometry:
Observatory, 88, 239, 1968.
Radio Observations:
Australian J. Phys., 21, 193, 1968.
Nature, 241, 260, 1973.
M.N.R.A.S., 167, 251, 1974.

18. 1973UGC...C...0000N
Re:UGC 07574
VV 188(a), Arp 120a
Paired with UGC 07575 at 4.4, 343
See UGC 07494
SA(s)0/a pec: (de Vaucouleurs), Sa pec (Holmberg)
In Arp's class "E and E-like galaxies close to and perturbing spirals"
"E galaxy breaking up a spiral" (Arp)

19. 1964RC1...C...0000d
Re:NGC 4438
= Holm 409a
Very small, very bright nucleus in a bright bulge partially hidden by strong,
complex, dark lane. Faint, irregular, outer part and dark markings.
Strongly distorted by NGC 4435 at 4.3 arcmin.
Photograph:
Ap. J., 138, 876, 1963.

20. 1959VV....C...0000V
Re:VV 188
= NGC 4438
Strong distortion and tails.
Similar to VV 230, VV 231, and VV 234.
On the photograph, neighboring SB0, NGC 4435 has a velocity
(V = +796 km/sec) that is too different for a physical
association. Either a galaxy which appears distant is having an
influence, or here the two systems are merging.


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