2006MNRAS.370..891J


Query : 2006MNRAS.370..891J

2006MNRAS.370..891J - Mon. Not. R. Astron. Soc., 370, 891-901 (2006/August-1)

Measurement of non-axisymmetry in centres of advanced mergers of galaxies.

JOG C.J. and MAYBHATE A.

Abstract (from CDS):

We measure the non-axisymmetry in the luminosity distribution in the inner few kpc of the remnants of advanced mergers of galaxies with a view to understand the relaxation in the central regions. For this, we analyse the images from the Two-Micron All-Sky Survey (2MASS) archival data for a selected sample of 12 merging galaxies, which show signs of interaction but have a single nucleus. The central regions are fitted by elliptical isophotes whose centres are allowed to vary to get the best fit. The centres of isophotes show a striking sloshing pattern with a spatial variation of up to 20-30 per cent within the central 1 kpc. This indicates mass asymmetry and a dynamically unrelaxed behaviour in the central region. Next, we Fourier-analyse the galaxy images while keeping the centre constant and measure the deviation from axisymmetry in terms of the fractional Fourier amplitudes (A1, A2, etc.) as a function of radius. All the mergers show a high value of lopsidedness (up to A1 ∼ 0.2) in the central 5 kpc. The m = 2 asymmetry is even stronger, with values of A2 up to ∼0.3, and in three cases these are shown to represent bars. The corresponding values denoting non-axisymmetry in inner regions of a control sample of eight non-merger galaxies are found to be several times smaller.

Surprisingly, this central asymmetry is seen even in mergers where the outer regions have relaxed into a smooth elliptical-like r1/4 profile or a spiral-like exponential profile. Thus, the central asymmetry is long lived, estimated to be ∼1Gyr, and hence lasts for over 100 local dynamical time-scales. These central asymmetries are expected to play a key role in the future dynamical evolution of the central region of a merger, and can help in feeding of a central active galactic nucleus.


Abstract Copyright: 2006 The Authors. Journal compilation © 2006 RAS

Journal keyword(s): galaxies: evolution - galaxies: kinematics and dynamics - galaxies: interactions - galaxies: photometry - galaxies: structure

Simbad objects: 23

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Number of rows : 23
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
#notes
1 M 31 G 00 42 44.330 +41 16 07.50 4.86 4.36 3.44     ~ 12388 1
2 M 33 GiG 01 33 50.8965749232 +30 39 36.630403128 6.17 6.27 5.72     ~ 5728 1
3 M 74 G 01 36 41.7451236624 +15 47 01.107512304 10.52 10.00 9.46 9.16   ~ 1677 1
4 ESO 307-25 IG 06 13 47.6258341728 -37 40 36.600431556   14.76   12.95   ~ 25 0
5 NGC 2655 LIN 08 55 37.731 +78 13 23.10   12.03 11.08     ~ 289 2
6 MCG-02-25-006 IG 09 36 28.0547875968 -11 19 50.115901476   13.91   12.63   ~ 21 0
7 NGC 3147 Sy2 10 16 53.6388580752 +73 24 02.641798224   11.43 10.61     ~ 474 2
8 NGC 3256 IG 10 27 51.284 -43 54 13.55   11.83 11.33 10.62 11.9 ~ 826 2
9 NGC 3414 GiP 10 51 16.2099174408 +27 58 30.297624852   12.1       ~ 323 0
10 NGC 3921 IG 11 51 06.8803989360 +55 04 43.414457484   13.4 12.64     ~ 243 0
11 NGC 4194 AGN 12 14 09.615 +54 31 35.93   13.79 13.30     ~ 442 2
12 M 99 H2G 12 18 49.625 +14 24 59.36 10.45 10.44 9.87     ~ 887 2
13 M 100 AGN 12 22 54.9299993592 +15 49 20.296257960 10.04 10.05 9.35     ~ 1801 2
14 NGC 4540 GiG 12 34 50.8741239840 +15 33 06.116283900   12.5       ~ 188 1
15 NGC 4670 IG 12 45 17.150 +27 07 31.76   12.6 12.90     ~ 251 0
16 NGC 4689 H2G 12 47 45.5568088416 +13 45 46.135889100   12.8       ~ 374 0
17 NGC 5248 GiG 13 37 32.0145074088 +08 53 06.496982448   11.4       ~ 492 0
18 NGC 5377 AGN 13 56 16.6722507720 +47 14 08.568249072   12.39 11.46 10.87 10.25 ~ 224 1
19 APG 254 IG 15 21.5 -07 22           ~ 3 0
20 NGC 6052 IG 16 05 12.8715178104 +20 32 32.607297132 13.01 13.44 13.00     ~ 348 2
21 NGC 7252 IG 22 20 44.7748209648 -24 40 41.909518200 12.26 12.46 12.06 11.57   ~ 696 1
22 NGC 7625 IG 23 20 30.132 +17 13 32.16 13.31 13.23 11.98 11.25   ~ 260 0
23 NGC 7727 GiP 23 39 53.870 -12 17 34.84   11   10.55   ~ 169 0

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2023.10.03-02:50:22

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