2009A&A...503...73C


C.D.S. - SIMBAD4 rel 1.7 - 2021.05.11CEST12:34:16

2009A&A...503...73C - Astronomy and Astrophysics, volume 503, 73-86 (2009/8-3)

Molecular gas in NUclei of GAlaxies (NUGA). XII. The head-on collision in NGC 1961.

COMBES F., BAKER A.J., SCHINNERER E., GARCIA-BURILLO S., HUNT L.K., BOONE F., ECKART A., NERI R. and TACCONI L.J.

Abstract (from CDS):

We present high-resolution maps of the CO(1-0) and CO(2-1) emission from the LINER 2 galaxy NGC1961. This galaxy is unusual among late-type (Sc) disk galaxies in having a very large radial extent and inferred dynamical mass. We propose a head-on collision scenario to explain the perturbed morphology of this galaxy - both the off-centered rings and the inflated radius. This scenario is supported by the detection of a steep velocity gradient in the CO(1-0) map at the position of a southwest peak in radio continuum and near-infrared emission. This peak would represent the remnant of the disrupting companion. We use numerical models to demonstrate the plausibility of the scenario. While ram pressure stripping could in principle be important for shocking the atomic gas and produce the striking head-tail morphology, the non detection of this small galaxy group in X-ray emission suggests that any hot intragroup medium has too low a density. A prediction of the collision model is the propagation of ring waves from the center to the outer parts, superposed on a probable pre-existing m=2 barred spiral feature, accounting for the observed complex structure of rings and spokes. This lopsided wave accounts for the sharp boundary observed in the atomic gas on the southern side. Through dynamical friction, the collision finishes quickly in a minor merger, the best fit being for a companion with a mass ratio 1:4. We argue that NGC1961 has a strongly warped disk, which gives the false impression of a nearly face-on system; the main disk is actually more edge-on, and this error in the true inclination has led to the surprisingly high dynamical mass for a morphologically late-type galaxy. In addition, the outwardly propagating ring artificially enlarges the disk. The collision de-stabilizes the inner disk and can provide gas inflow to the active nucleus.

Abstract Copyright:

Journal keyword(s): galaxies: individual: NGC1961 - galaxies: interactions - galaxies: ISM - galaxies: kinematics and dynamics - galaxies: nuclei - radio lines: galaxies

Simbad objects: 16

goto Full paper

goto View the reference in ADS

Number of rows : 16

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 NAME Cartwheel G 00 37 41.107 -33 42 58.79   19.26   18.52   ~ 256 1
2 M 32 IG 00 42 41.825 +40 51 54.61 9.51 9.03 8.08     ~ 2038 2
3 M 31 G 00 42 44.330 +41 16 07.50 4.86 4.36 3.44     ~ 11303 1
4 M 77 GiP 02 42 40.771 -00 00 47.84 9.70 9.61 8.87 10.1 9.9 ~ 4203 2
5 3C 111 Sy1 04 18 21.2773655604 +38 01 35.801523843   19.75 18.05     ~ 874 1
6 RAFGL 618 pA* 04 42 53.6245215366 +36 06 53.397219192   16.32   12.59   C-rich 966 0
7 NGC 1961 LIN 05 42 04.775 +69 22 42.17   11.73 10.99     ~ 313 3
8 SN 1998eb SN* 05 42 12.02 +69 22 26.3     17.8     SNIa 12 1
9 8C 0716+714 BLL 07 21 53.4484901266 +71 20 36.362058601   15.5 14.17 14.27   ~ 1161 1
10 M 81 Sy2 09 55 33.17306143 +69 03 55.0609270   7.89 6.94     ~ 4060 5
11 NGC 3147 Sy2 10 16 53.632 +73 24 02.34   11.43 10.61     ~ 436 2
12 NGC 3718 GiP 11 32 34.8527469396 +53 04 04.494313634   11.35 10.61     ~ 353 1
13 M 58 SyG 12 37 43.597 +11 49 05.12 10.80 10.48 9.66     ~ 993 2
14 3C 279 Bla 12 56 11.1664521013 -05 47 21.531840471   18.01 17.75 15.87   ~ 2777 2
15 EM* MWC 349 ** 20 32 45.499080 +40 39 36.74124   15.88 13.15 12.13   Bep 723 0
16 3C 454.3 Bla 22 53 57.74798 +16 08 53.5611   16.57 16.10 15.22   ~ 2569 2

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2009A&A...503...73C and select 'bookmark this link' or equivalent in the popup menu


2021.05.11-12:34:16

© Université de Strasbourg/CNRS

    • Contact