NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2018-07-23 T06:06:08 PDT
Help | Comment | NED Home

Notes for object NGC 4395

31 note(s) found in NED.


1. 2009A&A...493..871S
Re:UGC 07524
UGC 7524 is a prototype of a kinematically lopsided galaxy. The rotation curve
on the receding side continues to rise, whereas on the approaching side the
rotation curve quickly reaches a flat part (see also Swaters et al. 1999).

2. 2009A&A...493..871S
Re:UGC 07524
UGC 7524. This is the best resolved galaxy in our sample, yet the H I and
H{alpha} rotation curves show significant differences. The velocity field of
this galaxy shows a great deal of structure, including kinematic lopsidedness
(see Swaters et al. 1999). The structure seen in the dBB curve is also seen
along the major axis of the H I data.

3. 2008MNRAS.390..466E
Re:UGC 07524
UGC 7524. The velocity field only covers the bar of the galaxy which is almost
aligned with the H I major axis position angle, thus no rotation curve has been
plotted. Furthermore, only the central part of this galaxy is seen in our field
of view.

4. 2007MNRAS.382.1552L
Re:NGC 4395
NGC 4395: The radio, IR, optical and X-ray characteristics of this galaxy have
been extensively discussed by several authors (e.g. Lira et al. 1999; Iwasawa et
al. 2000; Moran et al. 2005; Peterson et al. 2005; Skelton et al. 2005; Minezaki
et al. 2006; Wrobel & Ho 2006a).

5. 2007AJ....134..648M
Re:NGC 4395
NGC 4395 (Figs. 7.22, 9.22, 20.22): This is one of those objects for
which the nucleus is at the limit of resolution. It is the object of the
latest Hubble type in our sample (Sm). With such a small contribution of
the bulge, only several scattered stellar clusters are seen apart from the
nucleus and a region of diffuse light 10-20 pc to the west of it.

6. 2006ApJS..165..461K
Re:NGC 4395
NGC 4395. There were five pointings for this galaxy, and the positions of the
DensePak fibers are shown on an R-band image (W. J. G. de Blok 2005, unpublished
data). The H{alpha} line overlapped slightly with a sky line. This was not a
serious problem for this galaxy, because the emission lines (particularly the
H{alpha} line) were very strong. The H{alpha} line was measured in a fiber if
the [N II] {lambda}6584, [S II] {lambda}6717, and [S II] {lambda}6731 lines were
visible and strong and if the H{alpha} line was stronger than the neighboring
sky lines. With these criteria, H{alpha} was detected in nearly all the fibers.
The fiber velocities were the average of the H{alpha} and [S II] {lambda}6717
lines. The position angle of BB02 was used as the DensePak position angle. The
DensePak rotation curve is consistent with the long-slit H{alpha} curve of BB02,
as well as the H I curve (Swaters 1999) at the innermost radii. At the outer
radii, the H I curve falls below the optical data at about the 2 {sigma} level.

7. 2006ApJS..165..461K
Re:NGC 4395
NGC 4395. There is moderate agreement between the DensePak isothermal halo
parameters and the values of the parameters found by BB02 (R_c_ = 0.9 +/- 0.1,
{rho}_0_ = 175.6 +/- 18.9). The NFWfree concentration determined by the DensePak
data is between the values listed in BB02 (c = 12.1 +/- 0.9, V_200_ = 69.7 +/-
3.8) and van den Bosch & Swaters (2001; c = 8.5, V_200_ = 71.9). As with UGC
5750, although the formal NFW fit parameters differ, the degeneracy between halo
parameters is such that there is little to distinguish the resulting halo
rotation curve. BB02 find the isothermal halo to be a slightly better fit to the
data than the NFW halo, whereas the DensePak data have a slight preference for
the NFW halo. The NFW halo certainly cannot be excluded, because it has a
reasonable concentration in all three fits. The misalignment of the minor axis
in the DensePak velocity field (see also Garrido et al. 2002; Noordermeer et al.
2001) and effects from star formation (BB02) need to be considered. The presence
of a bar may create strong enough noncircular motions that the true potential is
underestimated. Correcting for this would cause the halo profile to become more
NFW-like. However, bars are disk dynamical features and imply that the disk has
mass (which has so far been ignored in the minimum-disk case) and would cause
the halo profile to become more corelike.

8. 2006A&A...460...45G
Re:NGC 4395
NGC 4395 (UGC 7524). The unresolved nuclear source is seen in both (4.5-8* keV)
and 6-7 keV band images (Fig. 5). Moran et al. (2005) recently published[*] the
first high-quality, broadband X-ray detection of the AGN of this object,
confirming the rapid, large-amplitude variability reported in previous studies
(Iwasawa et al. 2000; Shih et al. 2003) and confirmed with XMM-Newton EPIC-pn
data (Vaughan et al. 2005). They fit a single power law model with absorption by
neutral material to the spectrum of the nuclear 5" ({GAMMA} = 0.61 and N_H_ =
1.2 x 10^22^ cm^-2), which provides a poor fit over the entire Chandra 0.5 to 9
keV range, but they claim it is excellent for energies above ~1.2 keV. Our best
model results in a single absorbed power law as well, but with somewhat stronger
absorption (N_H_ = 2.87 x 10^22^ cm^-2^) and a higher spectral index ({GAMMA} =
1.44, see Table 6). The iron line that is clearly resolved in the time-averaged
ASCA spectrum shown by Shih et al. (2003) is also visible in our spectrum (see
Fig. 3).

9. 2006A&A...452..739S
Re:NGC 4395
X2 in NGC 4395.
The galaxy NGC 4395 has a loose and disconnected appearance containing the
faintest and nearest Seyfert 1 nucleus currently known and classified as Sc/Irr
type. The proposed counterpart of X2 in NGC 4395 is a very compact and faint
radio source in the peripheral outskirts of the galaxy (electronic Fig. 4). With
the present data it is difficult to assess whether the object is associated to
NGC 4395 itself.

10. 2005ApJS..157...59L
Re:NGC 4395
This is a Magellanic spiral galaxy at a distance of 3.6 Mpc hosting a Seyfert 1
nucleus. ULX1 (IXO 53) is located on a knotty spiral arm.

11. 2003ApJS..146..353M
Re:NGC 4395
NGC 4395 (C)
This galaxy is almost too nearby to classify. At H the brightest stars
are resolved, which makes it difficult to trace the circumnuclear dust
structure in the color map. There are a few amorphous shapes, however,
along with some emission coincident with the active nucleus and other
star formation.

12. 2003A&A...398..467K
Re:NGC 4395
NGC 4395. This face-on Sd galaxy with a Seyfert 1 type nucleus also
extends beyond the WFPC2 field. According to Karachentsev & Drozdovsky
(1998), its distance via the brightest blue stars is 4.2+-0.8 Mpc. The
CM diagram in Fig. 2 reveals about 21 800 stars seen both in the V and
I bands. The majority of the detected stars are likely RGB stars.
From the TRGB position we derive a distance of 4.61 +- 0.57 Mpc, which
agrees well with the previous distance estimate.

13. 2002ApJS..143..257K
Re:NGC 4395
1225+3332ra.---Galactic absorption contaminating C IV and Mg II.

14. 2002AJ....124..675C
Re:UGC 07524
Huge galaxy; the NVSS flux is too low. CfA Seyfert 1
(Huchra & Burg 1992).

15. 2002A&A...387..821G
Re:UGC 07524
UGC 7524 (NGC 4395)
This magellanic galaxy is a Seyfert 1 type. It is quite near and thus
only the central part can be seen in the GHASP field of view, with
huge HII regions in the southeastern part. The slope of the rotation
curve is very slow, with a decreasing part at about 1 arcmin from the
center, especially well marked on the redshifted side, and no plateau
is being reached within 3 arcmin from the center. Indeed, the WHISP
HI data even suggest that the rotation curve is still rising at 8 arcmin
from the center, at least for the redshifted side.

16. 2002A&A...385..816D
Re:NGC 4395
N3274/U5721, N4395/U7524: In general there is excellent agreement
between the various raw data sets. The H{alpha} curves rise a bit
faster than the H I.

17. 2001MNRAS.325.1017V
Re:UGC 07524
UGC 7524: This galaxy has the best resolved rotation curve of all galaxies
analysed here. Unfortunately, equation (1) does not yield a reasonable fit
to the observed H I surface density, and we therefore opted to use the
full-resolution data (see Section 2) to model the unsmeared H I surface
density distribution. The data favour {UPSILON}_R_ <~ 4(M/L)_sun_ and low
values for {alpha}. However, for {alpha} = 1 we find
c ~ 8.5 - 3.6{UPSILON}_R_, consistent with CDM.

18. 2001ApJS..133...77H
Re:NGC 4395
NGC 4395 (S1.8). - NGC 4395 holds the distinction of hosting the
Seyfert 1 nucleus with the lowest known optical luminosity (Filippenko &
Sargent 1989), and one of the intrinsically weakest nuclear X-ray sources
observed so far (Lira et al. 1999; Moran et al. 1999). NGC 4395 is also
highly unusual as an AGN host because of its late Hubble type: it is
classified as a Magellanic spiral (Sm), only 3.6 Mpc away, with an absolute
magnitude of M_B_T__^0^ = -17.2. Sramek (1992; see also Moran et al. 1999)
previously observed the nucleus with the VLA, and he detected an unresolved
core with S_6_ = 0.6 mJy ({DELTA}{theta} = 0.4") and S_20_ = 1.24 mJy
({DELTA}{theta} = 1.4"). We measure S_6_ = 0.80 mJy and S_20_ = 1.68 mJy,
which indicates that the source has not varied significantly. Our 6 cm map
is more sensitive than Sramek's, who made use of archival data taken in
1982.

19. 2001AJ....122..637H
Re:NGC 4395
NGC 4395. - Using an absorbed power-law model, Moran et al. (1999)
found a mean 0.2-2.0 keV flux of about twice our value, even though they
measured approximately the same count rate from the same data. Their
best-fit model indicated a much flatter power law ({GAMMA} = 0.9) than
that which we have adopted here. Thus, in this case, different assumptions
about the spectrum have led to different fluxes.

20. 2000MNRAS.319...17L
Re:NGC 4395
NGC 4395: This galaxy contains the faintest and nearest Seyfert 1 nucleus
known today (Filippenko & Sargent 1989; Lira et al. 1999). Its nuclear
X-ray source is highly variable, and the continuum is well fitted by a
power-law distribution with photon index {GAMMA} = 1.7 (Iwasawa et al.
2000). The bright source seen in Fig. 20 (X2) has no obvious optical
counterpart.

21. 1999ApJS..125..409C
Re:UGC 07524
UGC 07524. - Position of the Seyfert nucleus, a compact radio source
(Sramek 1982).

22. 1997ApJS..112..391H
Re:NGC 4395
NGC 4395.--This galaxy holds the special distinction of hosting the least
luminous (M_B_=-9.8 mag) and nearest (2.6 Mpc) Seyfert 1 nucleus known
(Filippenko & Sargent 1989). As in Filippenko & Sargent, the narrow components
of H{alpha} and [N II] were removed from the blend, using [S II] as a model
(Fig. 12d). The narrow lines, whose FWHMs are 40-50 km s^-1^ (Filippenko & Ho
1997), are unresolved at the current resolution. As confirmed by the
high-resolution spectra of Filippenko & Ho, the narrow-line profiles all have a
blue asymmetric tail. Although the FWHM of the broad H{alpha} component is only
~500 km s^-1^, the base of the line stretches to a FWZI of ~5000 km s^-1^ (less
than the 7000 km s^-1^ quoted by Filippenko & Sargent 1989). A broad component
is present in a number of other optical (Filippenko & Sargent 1989) and
ultraviolet (Filippenko, Ho, & Sargent 1993) emission lines.

23. 1997A&A...319...33A
Re:NGC 4395
NGC 4395 This field contains a large number of strong X-ray sources. There seem
to be no dominant pairings or alignments, however, so the field has not been
pictured here. Detailed study of the individual sources might show pairing from
secondary sources as seen later in the NGC 5273 and 5548 fields.

24. 1996ApJ...463..498S
Re:NGC 4395
A9. NGC 4395
This is the least luminous Seyfert 1 galaxy known (M_B_ = -9.8; Filippenko &
Sargent 1989). Filippenko, Ho, & Sargent (1993) obtained FOS spectra and
WF/PC 1 images centered on narrow-band images. The UV spectrum resembles those
of Seyfert 1's, and the narrow-band images are unresolved. The nuclear
emission is unresolved with a maximum extent of 0.5" (10 pc).

25. 1995ApJS...98..477H
Re:NGC 4395
NGC 4395 hosts the nearest (d~2.6 Mpc), lowest luminosity (M_B_~-10 mag)
Seyfert 1 nucleus known (Filippenko & Sargent 1989). HST observations
reveal a UV spectrum similar to those of normal Seyferts (Filippenko, Ho,
& Sargent 1993). The widths of the narrow lines are extremely small,
being unresolved in the present survey; high-resolution observations with
an echelle spectrograph yield FWHM ~ 40 - 50 km s^-1^ (Ho & Filippenko
1995). The narrowness of the lines undoubtedly reflects the shallow
gravitational potential of the late-type spiral bulge (Sd III-IV).
Stringent limits on the stellar content of the nucleus of NGC 4395
(Filippenko et al. 1993; Filippenko & Ho 1995) provide a powerful
challenge to the hypothesis that the AGN phenomenon originates from
starburst activity (Terlevich et al. 1992).

26. 1994CAG1..B...0000S
Re:NGC 4395
B4 Group
Hubble Atlas, p. 37
SdIII-IV
PH-7145-S
Feb 1/2, 1976
103aD + GG11
panel S6
45 min
Racine wedge
Parts of this single galaxy were catalogued
separately as NGC 4395, NGC 4399, NGC 4400,
and NGC 4401 in the Dreyer NGC Catalog.
The moderately high surface brightness
center was given one NGC number; the several
separate bright associations in the loose spiral
pattern were the other three. The entire complex
is called NGC 4395 here.
The galaxy is in the nearby, low-redshift
group in the complex Ursa Major region called
Group B4 by Kraan-Korteweg and Tammann
(1979) and CVn I by de Vaucouleurs (1975).
The group is important for the distance scale
problem because it contains NGC 4214 (SBm;
panel 330) and IC 4182 (not in the RSA or this
atlas), both of which produced supernovae whose
absolute magnitudes can be calibrated once
precise (Cepheid) distances to these galaxies are
known.
The brightest stars in NGC 4395 begin to
individually resolve at about B = 18. Many
associations of bright young stars exist in the
several arms, similar to the pattern of the
associations in NGC 300 and in M33.
The nucleus is bright (B about 16) and is
starlike at 0.8" resolution.
The redshift of NGC 4395 is v_o = 304. The
distance modulus is estimated to be about
m - M = 28.5 on the scale where m - M = 29.3 for
M101 and m - M = 31.7 for the Virgo Cluster core.
The bright stars show secondary images
from the Racine wedge that are 5 mag fainter
than the primaries and are separated by 18".

27. 1976RC2...C...0000d
Re:NGC 4395
NGC 4399, NGC 4400 and NGC 4401 are part of it.
HII Regions and Distance Modulus:
Ap. J., 194, 559, 1974.

28. 1973UGC...C...0000N
Re:UGC 07524
SA(s)m: (de Vaucouleurs), Sc+ (Holmberg)
Low surface brightness
NGC 4399, NGC 4400 and NGC 4401 are condensations in the disk

29. 1964RC1...C...0000d
Re:NGC 4395
NGC 4399, NGC 4400 and NGC 4401 are details.
Lick 1956 velocity is based on the 2 emission patches in NGC 4401:
V = +312 km/sec.
Very low surface brightness. Irregular arms. Partly resolved.
See also HA, 105, 231, 1937.
HII Regions:
Zeit. fur Ap., 50, 168, 1960.

30. 1961Hubbl.B...0000S
Re:NGC 4395
Sc/Irr
S-330-P
Mar.28/29,1919
S23
4 hr 30 min
Enlarged 3.5X
This galaxy is so loose and disconnected that visual
observers counted each of four of the brighter patches as
individual nebulae and catalogued them as separate objects
in the New General Catalogue. The surface brightness
is so low, and the plate so underexposed, that this
reproduction has been double-printed; i.e., a copy negative
was made from the original plate, and the print on
photographic paper was made from the copy negative.
This process increases the contrast. Note the extreme
resolution into stars. Spiral arms can be traced, but the
general pattern resembles that of the Large Magellanic
Cloud.

31. 1918PLicO..13....9C
Re:NGC 4395
This appears to be an exceedingly faint, very large, and very irregular spiral,
covering an area about 8' in diameter; many almost stellar condensations;
no true nucleus. 27 s.n.


Back to NED Home