NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-02-22 T02:01:54 PST
Help | Comment | NED Home

Notes for object NGC 0718

11 note(s) found in NED.


1. 2007AJ....134.2286H
Re:KIG 0068
CIG 68: The galaxy was classified as SAB(s)a (NED). The gray-scale R-band image
shows a central elongated structure from which two arms emerge, while the
sharp-filtered image shows traces of a bar. The (B - I) color map shows a bluer
ring elongated in the direction of the bar and an adjacent dust lane. The
composed JHK image shows a prominent bar and two arms. We classify this galaxy
as SB(r)a. The (B - V) color is representative of Sa types. The photometric I-
and JHK-band ({epsilon} and P.A.) profiles show evidence of a bar in this
galaxy.

2. 2005MNRAS.362.1319L
Re:NGC 0718
NGC 718. This galaxy has a primary bar extending to r= 20 arcsec and also shows
weak evidence of a secondary bar at r= 5 arcsec (Figs 1 and 5), previously
detected in the R band by ES03 as an elliptical inner component. Both structures
appear as minima in the q profile and in the case of the primary bar, also as a
rapid change in the position angle at the end of the bar. Both features have
significant peaks in the m= 2 and m= 4 amplitudes of density. For the primary
bar, the m= 2 and m= 4 phases are also maintained nearly constant in the bar
region, and in the polar angle map the bar is identified as an intensity maximum
at r= 20 arcsec. The weak innermost structure can be detected also in the polar
angle map and marginally in the unsharp mask.

3. 2005MNRAS.362.1319L
Re:NGC 0718
NGC 718. Bulge/disc/bar decomposition was made, which gives a reasonable
solution even if the central elliptical structure is not taken into account. In
principle, this solution gives an upper limit to the B/T light ratio, although
most probably the central elliptical has only a minor effect on the relative
mass of the bulge. In order to test the influence of the bar to the B/T ratio,
both a Ferrers and a Sersic function were applied to the bar. The largest
relative bulge mass was obtained using a flat Ferrers function (n_bar_= 1),
which gave B/T= 0.23, whereas the Ferrers function with n_bar_= 4 gave a similar
relative bulge mass as obtained using a Sersic function for the bar (B/T= 0.20
and B/T= 0.18, respectively). In any case the type of function used to fit the
bar appeared to have only a minor effect on the obtained B/T light ratio. The
surface brightness profile of this galaxy looks interesting, because it shows an
exponential-like behaviour only in the outer part of the galaxy, whereas the
surface brightness declines at the radius where the bar ends (at r= 25 arcsec).
The non-exponential disc is visible also in the residual image as negative
pixels. The residual image also shows the flux of the spiral arms above the
disc.

4. 2004A&A...415..941E
Re:NGC 0718
NGC 718: Erwin (2000); see Erwin & Sparke (2003). Adopted inner-bar
L_bar_ is that of the blue nuclear ring in Erwin & Sparke (2003).

5. 2002AJ....124..675C
Re:UGC 01356
This diffuse radio source is not in the NVSS catalog.

6. 1994CAG1..B...0000S
Re:NGC 0718
Hubble Atlas, p. 11
Sa
(E,L,0)
PH-792-S
Aug 25/26, 1954
103aO + WG2
30 min
Two high-surface-brightness inner arms
emerge from what is either an internal ring
surrounding the inner disk or what is yet another set
of tightly wound spirals close to the center. Both
these interior features show well in the reproduction
here and in the print in the Hubble Atlas.
Two symmetrically placed outer arms of low
surface brightness can be traced inward until
they nearly merge with the high-surface-brightness
intermediate set of arms that hug the outside
of the high-surface-brightness arms for about a
quarter-turn each. The entire form is highly
symmetrical. The galaxy is placed here in the MAS
subset of Sa galaxies because of the pattern of
4-6 arms.
This galaxy, together with NGC 3269 and
NGC 3626, also shown on this page, are the type
examples of the smooth-armed Sa class. Both
NGC 718 and NGC 3626 are isolated. NGC
3269 is a member of the Antlia Cluster. Because
smooth-armed Sa galaxies occur in the isolated
field, their form is not due to environmental
effects but is generic to the classification
sequence (Sandage 1983a).

7. 1994CAG1..B...0000S
Re:NGC 0718
Hubble Atlas, p. 11
Sa
(E,L,0)
PH-792-S
Aug 25/26, 1954
103aO + WG2
30 min
NGC 718 is the earliest of the grand design
true Sa galaxies in this atlas. Earlier transition
cases, such as NGC 4429 [S0_3_(6)/Sa pec; panels
60, S2], NGC 3271 (Sa; panel 61), or NGC
4503 (panel 61) show a major two-armed
symmetry that will develop into a strong grand design
form later in the sequence; NGC 718 is the
earliest Sa with that robust form. The negative
print here is of high contrast, to emphasize the
smoothness and the symmetry of the outer spiral
pattern. The surface brightness of the outer arms
is, in fact, very low relative to the central bulge
and to the two smooth, symmetrical,
high-surface-brightness inner arms that are well seen
in the positive print on panel 63 but which are
burned out on the print here. As also seen on
panel 63, the inner arms are tightly wound about
the central bulge. They can each be traced only
for about a quarter turn from their emergence
tangent to a tight inner ring. These inner arms
are similar to, but are more developed than, the
rudimentary "pre-arms" in NGC 4429 (S0_3_/Sa
pec; panels 60, S2); hence the later classification
as an early Sa is awarded rather than the transition
S0/Sa type.

8. 1973UGC...C...0000N
Re:UGC 01356
SAB(s)a (de Vaucouleurs)
2 smooth arms, one slightly stronger
(R') 1.7 x 1.7, smooth extremely faint corona
Early SBa

9. 1973AISAO...8....3K
Re:KIG 0068
Sizes of the outermost isophotes are
2.1 x 2.7 arcmin (blue chart)
2.0 x 2.8 arcmin (red chart)

10. 1964RC1...C...0000d
Re:NGC 0718
Extremely bright nucleus
in a small, bright lens: 0.8 arcmin x 0.5 arcmin.
2 main smooth arms form pseudo (R): 1.4 arcmin x 1.2 arcmin.

11. 1961Hubbl.B...0000S
Re:NGC 0718
Sa
PH-792-S
Aug. 25/26, 1954
103aO + WG2
30 min
Enlarged 8.2X
NGC 0718 has three sets of spiral arms. The inner set is
very tightly coiled about a small nucleus. The nucleus
looks large here but this photographic effect in the
reproduction process is due to the coalescence of the inner,
tighly wound arms. The second set of arms can be seen
close to the burnedout nuclear region. The arm on the
northwest side is most easily visible. Finally, two very
faint arms sweep far from the nucleus. There is no trace
of resolution into stars over the entire galaxy.


Back to NED Home