NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-02-18 T14:37:02 PST
Help | Comment | NED Home

Notes for object NGC 1084

9 note(s) found in NED.


1. 2004MNRAS.355.1251L
Re:NGC 1084
NGC 1084, 4698, 4962, 5962 and 6753. There are some non-barred galaxies
in the sample whose decompositions were improved by modelling ovals by
a Ferrers function. As an example the decomposition for NGC 6753 is
shown in Fig. 2(b) (see the online version). In this case, the oval has
a relatively low surface brightness and cannot be directly
distinguished in the profile. However, it is prominent in direct images
and divides the zone between bright nuclear and outer rings (see
Crocker et al. 1996).
The decomposition remained unsatisfactory for the galaxies NGC 4487,
4900, 2139 and 4618. Characteristic for all these galaxies is that they
have little or no bulge, or that the bulge has very low surface
brightness in comparison with that of the disc. As an example, the
decomposition of NGC 4487 is shown in Fig. 2(b) (the online version).
For this galaxy, the bulge model has a very large shape parameter (n =
5), which appears immediately after giving the initial parameters of
the fit. Such a centrally peaked extended bulge is the only solution
for this galaxy, but it is not clear whether the solution is physically
reasonable. At least it is not intuitively expected in the profile,
where the bulge does not look very prominent. Among the sample galaxies
there is also one galaxy, NGC 4900, having a strong Freeman type II
profile, which makes it impossible to fit any usual global disc model,
unless a truncated disc is assumed. In this study, the radial
scalelength of the disc for this galaxy was estimated from the outer
regions of the disc, whereas the bulge model was extracted using the
inner portions of the image. The decomposition was uncertain also for
the two late-type spirals, NGC 2139 and 4618, both having an asymmetric
disc. NGC 4618 is a prototypical one-armed SBm spiral (de Vaucouleurs &
Freeman 1972) and most probably has no bulge at all.

2. 2002ApJS..143...73E
Re:NGC 1084
NGC 1084.---Sb: Bright nuclear point source. Bulge elongated along
disk major axis; no sign of a bar. Multiarm pattern, but arms not very
well defined. Inner arms have a number of bright knots. Arms wind
about 180deg before fading from view.

3. 1994CAG1..B...0000S
Re:NGC 1084
Hubble Atlas, p. 29
Sc(s)II.2
PH-7915-S
Nov 7/8, 1980
103aO
2 min
The surface brightness of the arm pattern in
NGC 1084 is exceptionally high. The well-exposed
image here was obtained in only a two-minute
exposure with the Palomar 200-inch Hale
Telescope; it is nearly overexposed even so.
The arms are massive in the sense of
Reynolds (1927a,b). There arc three arms, as in
IC 1954 and NGC 578 on this panel and NGC 3052
on panel 236. The best-developed of the
arms is on one side alone. The other two arms on
the opposite side in the outer region start as two
thin, luminous threads that themselves begin on
opposite sides of the center but overlap after
unwinding by half a turn, after which the spiral
pattern on that side is confused.
The redshift of NGC 1084 is v_o = 1478 km/s.

4. 1993A&AS...97..887B
Re:NGC 1084
NGC 1084 is an Sc(s)II.2 galaxy with warm dust and strong IRAS and
H{alpha} emission. The CO(1-0) intensity we detected is consistent with
S88. The line ratio in the center is 0.7 but is not constant with
velocity although the structure seen is similar in both lines. The low
velocity component (to the northeast) is stronger but has a lower line
ratio. We tested for a pointing error by convolving the CO(2- 1) about
several plausible positions and were not able to significantly reduce the
variation in line ratio across the profile, meaning that the line ratio
really varies. Both lines are strong out to about 40" in both directions
along the major axis and detected to 1' which is the limit to the visible
emission in the Hubble Atlas (Sandage 1961) photograph. The total HI and
H_2_ masses appear about equal at about 5 x 10^9^ M_sun_. The radio
continuum (Condon 1983) emission is strong and extended with structure
down to their 6" beamsize.

5. 1976RC2...C...0000d
Re:NGC 1084
Photograph:
Ann. Ap., 27, 300, 1964.
Coll.Int. Novae & SN, CNRS, Paris, 179, 1965.
Cont. Asiago No. 174, 1965.
Mem. S.A. Ital., 40, 133, 1969 = Contr. Asiago No. 214.
Astrofizika, 6, 367, 1970.
Photometry:
Mem. S.A. Ital., 40, 133, 1969 = Contr. Asiago No. 214.
Astrofizika, 6, 367, 1970.
Spectrophotometry:
Ap. J., 163, 249, 1971.
Astr. Ap., 33, 331, 337, 1974.
Astr. Ap., 33, 331, 337, 1974.
Dynamics and Rotation Curve:
Ap. J., 184, 735, 1973.
SN1963P
Asiago Cont. No. 174, 1965.
Tokyo Astr. Bull. No.176, 1967.
Radio Observations:
Austral. J. Phys., 21, 193, 1968.

6. 1964RC1...C...0000d
Re:NGC 1084
Very small, bright nucleus.
Filamentary knotty arms.
Photograph, Rotation and Mass:
Ap. J., 137, 376, 1963.
SN 1963
I.A.U. Circ. 1843, 1856.

7. 1961Hubbl.B...0000S
Re:NGC 1084
Sc
H-2354-H
Nov. 29/30, 1946
IIaO
10 min
Enlarged 7.1X
The three galaxies at the bottom of the facing page and
the six on page 30 form a separate subgroup of Sc in which
the spiral pattern is not so well defined as in the M101
type. The arms are usually not so "clean" and in some
galaxies not so well separated from each other as those in
the M101 Group. The one main arm in the northwest
quadrant of NGC 1084 is well defined. It is lined on its inside
edge with a dust lane. The spiral pattern on the east side
of NGC 1084 is not easy to trace as a single arm. Several dust
lanes and segments of spiral arms are present. Notice the
small nucleus of this galaxy.

8. 1957HPh....53..275d
Re:NGC 1084
SA(s)c
(Plate 19)
A small central nucleus from which start two main arms with
much irregular structure, bright knots and emission objects.
Only the bright knots are shown in this short-exposure image.
Compare with NGC 7205 (plate 18), NGC 7793 (Plate 20),
NGC 5962 (Plate 23) and NGC 4244 (Plate 42).

9. 1918PLicO..13....9C
Re:NGC 1084
A fairly bright, condensed, very patchy spiral 2.2' x 0.8' in p.a. 30^deg^. Very
faint stellar nucleus; several condensations in the whorls. 14 s.n.


Back to NED Home