Date and Time of the Query: 2019-05-23 T16:29:30 PDT
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Notes for object NGC 2993

12 note(s) found in NED.

1. 2003ApJ...598..827P
Re:NGC 2993
NGC 2992/2993.-NGC 2992 and NGC 2993 represent an interacting system and
exhibit extended tidal features in the optical images. The MUV
morphology of NGC 2992 shows faint, diffuse emission coincident with the
optical central bulge/disk and with low internal color dispersion. This
galaxy is very faint in the FUV images. NGC 2993 is well detected in
both UIT/FUV and UIT/MUV images. It is also noteworthy that NGC 2993 has
one of the bluest UVoptical colors of the UIT sample. This galaxy is
apparently vigorously forming stars, and these stars dominate the UV
portion of the galaxy's SED. The lack of internal color dispersion
between the MUV and optical images implies that the young stars also
dominate the flux emission at these wavelengths. There is low (but
significant) internal color dispersion between the FUV and MUV images in
NGC 2993, which is centered on the nucleus and may be suggestive of a
dust lane or patchiness in the dust absorption.

2. 2001ApJS..137..139S
Re:NGC 2993
NGC 2992 and NGC 2993. - We use an H_0_ distance, based on the mean
velocity of the two group members.

3. 2001ApJS..132..129M
Re:NGC 2993
NGC 2993 (Arp 245). - This Sa spiral is a companion to NGC 2992. It is
oriented more face-on than NGC 2992. By contrast with NGC 2992, the UV
images (Fig. 16a) show a bright, centrally peaked source, identified as a
probable starburst nucleus. The tracking was poor for the FUV exposure,
leading to a slight tailing of the images.

4. 2001AJ....121.2483U
Re:NGC 2993
NGC 2993. - This interacting galaxy is nearly face-on, and the velocity
range is rather small. The rotation curve is warped, as in the case of
NGC 2782 (P.A. = 180^deg^). While the [N II]/H{alpha} is nearly constant,
the [S II]/H{alpha} becomes larger toward the outside of the galaxy.

5. 1998AJ....116.2166U
Re:NGC 2993
This galaxy is strongly interacting with NGC 2992, which is 3'
northwest of the galaxy. Tidal tails are seen in our original image and
the Carnegie Atlas. Star formation occurs in the central region, and
diffuse H{alpha} emission surrounds it.

6. 1998A&AS..130..333T
Re:PGC 027991
Pair with NGC2992 (ARP 245), galaxies in interaction, expected
respectively at V=2420 km/s (HI measurement, Richter & Huchtmeier,
1987A&AS...68..427R) and V=2314 km/s (LEDA, HI measurements). The two
corresponding emissions are well seen in the spectrum, but are not
separable (see Richteri & Huchtmeier, 1987A&AS...68..427R).

7. 1996ApJS..103...81C
Re:NGC 2993
NGC 2993.--Pair with the Seyfert 2 galaxy NGC 2992, which is an S = 205 mJy
radio source at 1.425 GHz (see Fig. 2).

8. 1994CAG1..B...0000S
Re:NGC 2993
Pair [with NGC 2992]
Feb 25/26, 1979
103aO + GG385
45 min
The orientation of the print here is north at
the top, east to the left. NGC 2992 is to the north
and west of NGC 2293, which has the more
circular image. The projected separation of the
pair is 3'. The redshifts are v_o(2992) = 1963 km/s
and v_o(2993) = 1868 km/s, giving a redshift
distance of 38 Mpc (H = 50) based on the mean
redshift. The projected linear separation of the
pair is, then, small at 33 kpc.
Tidal interaction is clearly visible.
Luminous material exists between the main
bodies of the principal components, extending
from NGC 2293 to the shred on the north side of
NGC 2992. This apparently torn-away part of
NGC 2992, of low surface brightness, is evidently
a tidal plume that nevertheless has knots that
are presumably small HII regions.
The smooth extended arm that starts on the
north edge of the southern component of the pair
(NGC 2993) and extends eastward, appears also
to be a tidal plume.
The prints in the right column are from the
same plate used for the main print at the left. The
top print in this column shows that the shred torn
from NGC 2992 and the tidal-plume arm in NGC
2993 are both of low surface brightness relative
to the central regions of each galaxy. These
central regions are shown in the lower two prints
in the right column. Not shown well here but
visible on the plate is evidence of recent star
formation in the center of NGC 2992; hence its
assigned type is Sab.

9. 1988A&AS...75..273D
Re:NGC 2993
NGC 2993 is a spiral galaxy forming the strongly interacting system
Arp 245 (Arp, 1966) with NGC 2992, with which it has a velocity
difference of only 75 km s^-1^. Some ionized gas has been observed
around these two galaxies (DB87), which are both radio sources (Ward
et al., 1980). However, their similarities end here, since they have
quite different optical spectra. NGC 2993 is not an X-ray source, and
is HI deficient (Richter and Huchtmeier, 1987).
We find for NGC 2993 a nuclear redshift z = 0.0079 +/- 0.0002,
corresponding to a galactocentric velocity of 2130 km s^-1^ and to a
distance (averaged with that of NGC 2992) of 42.0 Mpc.
We have detected an ionized envelope over 26.6" (5.5 kpc) along PA =
198^deg^. The ionized gas is seen to extend a little further away from
the nucleus towards the north-east than towards the south-west, a
result which is not clearly apparent from narrow band imaging (DB87).
The size of the ionized nebulosity detected through long slit
spectroscopy is a little larger than found through narrow band imaging
(23"). As seen from figure 6 and table VIII, NGC 2993 has a nuclear
spectrum resembling that of NGC 6215, with [OI] 6300 detected at a
4{sigma}, 3{sigma} and 3{sigma} level in the nucleus and regions NE1
and SW1 respectively, suggesting as in previous cases the presence of
a LINER. The excitation degree of the ionized gas is larger in regions
NE2 and NE3 than in the rest of the envelope. The [OII] 3727/H{beta}
and [OIII] 5007/H{beta} intensity ratios measured in the nucleus agree
with those published by Ward et al. (1980), but H{alpha}/H{beta},
[NII] 6584/H{beta} and [SII] 6717-6731/H{beta} strongly differ from
the values observed by these authors through a 1.5" slit. In
particular, we find a notably smaller amount of reddening (derived
from H{alpha}/H{beta}). Such discrepancies may be partly due to their
lower signal to noise. Since the value of the extinction A_v_ required
by Ward et al. (1980) to account for the radio emission of NGC 2993 in
the thermal hypothesis is notably larger than our observed value, it
seems probable that some of the radio emission is non thermal. Other
observations at radio frequencies are obviously needed to derive the
radio spectral index and estimate the relative importances of these
two components.
The H{alpha}/H{beta} ratio gives colour excesses E(B-V) quite
similar for all the regions of NGC 2993: 0.62-0.78. The values of T_e_
range between 7500 and 9400 K. E(B-V), T_e_ and n_e_ are given in
table VIII.
The ionized gas around NGC 2993 shows no velocity gradient along PA
= 198^deg^: {delta}v <50 km s^-1^.

10. 1976RC2...C...0000d
Re:NGC 2993
Part of Arp 245
Interacting pair with NGC 2992 at 2.9 arcmin
Photograph and Spectrum:
Ap. J. (Letters), 178, L43, 1972.

11. 1968MCG4..C...0000V
Re:MCG -02-25-015
Outstanding, bright interacting pair with MCG -02-25-014
{rho} = 3.0 arcmin.
Linked with wide arches, nicely visible.
Photo: Arp 245.
On the negative a narrow arm is visible, stretching to the
south 3 arcmin.

12. 1964RC1...C...0000d
Re:NGC 2993
Very bright, double nucleus with an asymmetric arm or loop. Faint outer
Interacting pair with NGC 2992 at 2.9 arcmin.

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