Date and Time of the Query: 2019-02-20 T02:56:32 PST
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Notes for object NGC 4457

11 note(s) found in NED.

1. 2006MNRAS.366..812C
Re:NGC 4457
The distribution and the kinematics of this galaxy are very peculiar. There is
little ionized gas in the receding side, which is traced by only few star
formation regions while the approaching side consists in a single H{alpha}
armlet. The core region surprisingly exhibits the most blue-shifted velocities
observed in the galaxy.

2. 2006ApJ...647..140F
Re:NGC 4457
This galaxy (L2, S0/a) has one bright central source with a hard spectrum,
embedded in soft diffuse emission. The spectrum of the central source is well
fitted by a power-law plus plasma model or a two-temperature plasma model
(L_0.5-10 keV_ = 1.9 x 10^39^ ergs s^-1^). This can be interpreted as the
spectrum of an embedded AGN and is confirmed by the detection of this source at
1.49 GHz (Condon 1987). From this detection we infer log R_X_ = -1.6, which
means that this source is radio-loud. The luminosity of the AGN is L_2-10 keV_ =
9.7 x 10^38^ ergs s^-1^, while the luminosity of the central 2.5" is L_2-10 keV_
= 1.8 x 10^39^ ergs s^-1^, so the AGN contributes ~55% of the X-ray luminosity.
The rest of the luminosity comes from the diffuse emission, so this LINER is a

3. 2006A&A...460...45G
Re:NGC 4457
NGC 4457 (UGC 7609). Hard emission is unresolved in the nucleus of this galaxy
(Fig. 5). The spectral analysis of ACIS Chandra data by Satyapal et al. (2005)
gives {GAMMA} = 1.57, kT = 0.69 keV, and no additional absorption, in very good
agreement with our results (see Table 6).

4. 2002ApJS..143...73E
Re:NGC 4457
NGC 4457.---(R)SB0/a: Bright, very elliptical nuclear source embedded
in a nearly circular bulge. Bulge is threaded by a weak bar. Bulge/bar
system is embedded in a fairly low surface brightness disk that has a
clear outer ring.

5. 1995AJ....109.1608R
Re:NGC 4457
The B image of this (R)SAB(s)0 type galaxy shows a strong dust lane
and clear spiral structure. An outer ring is clearly evident in both the
B and I mosaics.
The K image shows a short broad bar of length 7.23 arcsec aligned NE.
Spiral structure in the B image is traceable outside r=9 arcsec. Dust
lanes can be traced inward closer to the nucleus. A faint, partial arm,
visible in B, springs from the southwest end of the bar.

6. 1994CAG1..B...0000S
Re:NGC 4457
VCC 1145
Hubble Atlas, p. 9
Jan 9/10, 1948
30 min
NGC 4457 is at the southern extreme of the
Virgo Cluster Catalog survey region (Binggeli,
Sandage, and Tammann 1985) toward the
southern extension along the local supergalactic
plane (de Vaucouleurs 1956b).
The morphology of the spiral pattern in
NGC 4457 is unusual because the star-producing
spiral arms are entirely inside a smooth disk
which itself is inside an almost complete outer,
nearly detached, smooth ring. This disk and ring
morphology is characteristic of earlier-type
galaxies but is unusual in galaxies having
well-developed star-producing spiral arms, as in
NGC 4457 here.
The galaxy has one prominent arm of high
surface brightness and another, opposite
branched, complex of arms that are fainter and
are less well defined, seen best in the lighter print
at the right. The deeper print on the left shows
the disk, within which the arms reside. The insert
shows the outer, almost detached, smooth ring of
low surface brightness. This feature is composed
of overlapping opposite arms which attach to the
rim of the disk near the intersections of the ends
of the major axis of the disk with its edge.

7. 1994CAG1..B...0000S
Re:NGC 4457
VCC 1145
Hubble Atlas, p. 9
Jan 9/10, 1948
30 min
The print here of NGC 4457 is made from
the same plate used in the Hubble Atlas. The
moderately tightly wound arms and the dust on
the inside of the main arm are well seen in the
reproduction here. Small HII regions exist in
parts of the arms.

8. 1976RC2...C...0000d
Re:NGC 4457
Observatory, 88, 239, 1968.

9. 1973UGC...C...0000N
Re:UGC 07609
(R)SAB(rs)0/a (de Vaucouleurs)

10. 1964RC1...C...0000d
Re:NGC 4457
Very bright nucleus in an isolated bright lens: 1.4 arcmin x 1.0 arcmin with
spiral arms and dark lanes. Smooth (R): 2.0 arcmin x 2.0 arcmin.
Heidelberg Veroff. Vol. 9, 1926 and Lund 9 dimensions are for the lens only.

11. 1961Hubbl.B...0000S
Re:NGC 4457
Jan. 9/10, 1948
30 min.
Enlarged 11.9X
NGC 4457 has one prominent spiral arm of high surface
brightness, and another, fainter arm which is less well
defined. These arms are embedded in an envelope of low
surface brightness. Dust lanes lie on the insides of the
two arms. A faint external ring surrounds the entire
structure. The ring may not be completely detached from
the more central envelope, because a faint connection is
probably present on the east end of the major axis.

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