2021A&A...654A..24B


Query : 2021A&A...654A..24B

2021A&A...654A..24B - Astronomy and Astrophysics, volume 654A, 24-24 (2021/10-1)

Molecular gas kinematics in the nuclear region of nearby Seyfert galaxies with ALMA.

BEWKETU BELETE A., ANDREANI P., FERNANDEZ-ONTIVEROS J.A., HATZIMINAOGLOU E., COMBES F., SIRRESSI M., SLATER R., RICCI C., DASYRA K., CICONE C., AALTO S., SPINOGLIO L., IMANISHI M. and DE MEDEIROS J.R.

Abstract (from CDS):


Context. The study of the distribution, morphology, and kinematics of cold molecular gas in the nuclear and circumnuclear regions of active galactic nuclei (AGNs) helps to characterise and hence to quantify the impact of the AGNs on the host galaxy over its lifetime.
Aims. We present the analysis of the molecular gas in the nuclear regions of three Seyfert galaxies, NGC 4968, NGC 4845, and MCG-06-30-15, using Atacama Large sub-Millimetre Array (ALMA) observations of the CO(2-1) emission line. The aim is to determine the kinematics of the gas in the central (∼1 kpc) region and thereby to probe nuclear fueling and feedback of AGNs.
Methods. We used two different softwares, namely the 3D-Based Analysis of Rotating Object via Line Observations and DiskFit, to model the kinematics of the gas in the molecular disc, and thereby to determine the gas rotation and any kinematical perturbations.
Results. Circular motions dominate the kinematics of the molecular gas in the central discs, mainly in NGC 4845 and MCG-06-30-15; however there is clear evidence of non-circular motions in the central (∼1 kpc) region of NGC 4845 and NGC 4968. The strongest non-circular motion is detected in the inner disc of NGC 4968, mainly along the minor kinematic axis, with a velocity ∼115 km s–1. Of all DiskFit models, the bisymmetric model is found to give the best fit for NGC 4968 and NGC 4845, indicating that the observed non-circular motions in the inner disc of these galaxies could result from the nuclear barred structure, where the gas streams in elliptical orbits aligned along the bar. If the dynamics of NGC 4968 is modelled as a corotation pattern just outside of the bar, the bar pattern speed becomes Ωb = 52 km s–1 kpc–1; the corotation is set at 3.5 kpc; and the inner Lindblad resonance (ILR) ring is R = 300 pc, corresponding to the CO emission ring. In the NGC 4968 galaxy, the torques exerted on the gas by the bar are positive in the centre, within the gas nuclear ring, and negative outside. This shows that the gas is transiently trapped in the ILR. The comparison of the CO intensity maps with the map of the cold dust emission shows an absence of CO in the centre of NGC 4968; also the dust distribution and CO emission in and around the centre of NGC 4845 have similar extensions. The 1.2 mm ALMA continuum is peaked and compact in NGC 4968 and MCG-06-30-15, but their CO(2-1) emissions have extended distributions. Allowing the CO-to-H2 conversion factor αCO between 0.8 and 3.2, which is typical of nearby galaxies of the same type, the molecular mass M(H2) is estimated to be ∼3 - 12 x 107 M (NGC 4968), ∼9 - 36 x 107 M (NGC 4845), and ∼1 - 4 x 107 M (MCG-06-30-15).
Conclusions. We conclude that the observed non-circular motions in the molecular disc of NGC 4968 and likely those seen in NGC 4845 are due to the presence of the bar in the nuclear region. We discuss the possibility that the observed pattern in the kinematics might be a consequence of the presence of AGNs, and this might be the case for NGC 4845. At the current spectral and spatial resolution and sensitivity, we cannot claim any strong evidence in these sources of the long sought feedback or feeding effect resulting from the presence of AGNs.

Abstract Copyright: © ESO 2021

Journal keyword(s): galaxies: structure - ISM: kinematics and dynamics - galaxies: individual: NGC 4968 - galaxies: individual: NGC 4845 - galaxies: individual: MCG-06-30-15

Simbad objects: 19

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Number of rows : 19
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 NAME Sculptor Dwarf Galaxy G 01 00 09.4 -33 42 32   9.79 8.6 8.81   ~ 1265 4
2 M 77 GiP 02 42 40.7091669408 -00 00 47.859690204 9.70 9.61 8.87 10.1 9.9 ~ 4405 2
3 Mrk 1066 Sy2 02 59 58.5970307633 +36 49 13.808979663   14.89 13.96     ~ 338 1
4 NGC 1433 GiG 03 42 01.4847418992 -47 13 18.929092656   10.84 9.99 9.61 10.2 ~ 348 0
5 ESO 420-13 Sy2 04 13 49.699 -32 00 25.20   13.31 13.3 12.14   ~ 85 0
6 NGC 1566 Sy1 04 20 00.3968473248 -54 56 16.624708764 10.29 10.19 9.73 9.21 10.1 ~ 826 2
7 NGC 2273 Sy2 06 50 08.6691789600 +60 50 44.864645136   14.50 13.54     ~ 502 3
8 NGC 3227 GiP 10 23 30.5765149296 +19 51 54.282206700   12.61 11.79     ~ 1637 1
9 NGC 3256 IG 10 27 51.284 -43 54 13.55   11.83 11.33 10.62 11.9 ~ 808 2
10 NGC 4253 Sy1 12 18 26.5163572920 +29 48 46.531535472   14.34 13.57     ~ 1004 1
11 NGC 4388 Sy2 12 25 46.820 +12 39 43.45 11.91 11.76 11.02     ~ 1283 2
12 NGC 4845 AGN 12 58 01.242 +01 34 32.09   17.40 16.31     ~ 228 0
13 NGC 4948 EmG 13 04 55.953 -07 56 51.76   13.62   16.25 13.0 ~ 57 0
14 NGC 4968 Sy2 13 07 05.976 -23 40 37.34   13.78 14.79 12.46   ~ 172 1
15 ESO 383-35 Sy1 13 35 53.7691256160 -34 17 44.160716796   13.89 13.61 8.9   ~ 1443 0
16 NGC 5643 Sy2 14 32 40.778 -44 10 28.60   11.03 13.60 9.92 10.6 ~ 525 0
17 IC 5063 Sy2 20 52 02.329 -57 04 07.60   12.92 13.60 11.30   ~ 608 1
18 NGC 7465 GiP 23 02 00.9603717552 +15 57 53.236032120   13.3       ~ 289 0
19 NAME Virgo Extension GrG ~ ~           ~ 51 0

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2022.12.06-13:03:26

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