2018A&A...612A..66M


C.D.S. - SIMBAD4 rel 1.7 - 2019.11.11CET22:32:09

2018A&A...612A..66M - Astronomy and Astrophysics, volume 612A, 66-66 (2018/4-1)

MUSE observations of the counter-rotating nuclear ring in NGC 7742.

MARTINSSON T.P.K., SARZI M., KNAPEN J.H., COCCATO L., FALCON-BARROSO J., ELMEGREEN B.G. and DE ZEEUW T.

Abstract (from CDS):


Aims. We present results from MUSE observations of the nearly face-on disk galaxy NGC 7742. This galaxy hosts a spectacular nuclear ring of enhanced star formation, which is unusual in that it is hosted by a non-barred galaxy, and because this star formation is most likely fuelled by externally accreted gas that counter-rotates with respect to its main stellar body.
Methods. We used the MUSE data to derive the star-formation history (SFH) and accurately measure the stellar and ionized-gas kinematics of NGC 7742 in its nuclear, bulge, ring, and disk regions.
Results. We have mapped the previously known gas counter-rotation well outside the ring region and deduce the presence of a slightly warped inner disk, which is inclined at approximately 6° compared to the outer disk. The gas-disk inclination is well constrained from the kinematics; the derived inclination 13.7°±0.4° agrees well with that derived from photometry and from what one expects using the inverse Tully-Fisher relation. We find a prolonged SFH in the ring with stellar populations as old as 2-3Gyr and an indication that the star formation triggered by the minor merger event was delayed in the disk compared to the ring. There are two separate stellar components: an old population that counter-rotates with the gas, and a young one, concentrated to the ring, that co-rotates with the gas. We recover the kinematics of the old stars from a two-component fit, and show that combining the old and young stellar populations results in the erroneous average velocity of nearly zero found from a one-component fit.
Conclusions. The spatial resolution and field of view of MUSE allow us to establish the kinematics and SFH of the nuclear ring in NGC 7742. We show further evidence that this ring has its origin in a minor merger event, possibly 2-3 Gyr ago.

Abstract Copyright: © ESO 2018

Journal keyword(s): techniques: imaging spectroscopy - galaxies: structure - galaxies: kinematics and dynamics - galaxies: individual: NGC 7742

Simbad objects: 3

goto Full paper

goto View the reference in ADS

Number of rows : 3

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 GD 153 WD* 12 57 02.3224875106 +22 01 52.634392478 11.883 13.060 13.349 13.488 13.669 DA1.2 299 0
2 NGC 7742 GiP 23 44 15.7546655695 +10 46 01.536389590   12.5       ~ 191 0
3 NGC 7743 Sy2 23 44 21.1586928811 +09 56 02.970129689   14.19 13.28     ~ 283 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2018A&A...612A..66M and select 'bookmark this link' or equivalent in the popup menu


2019.11.11-22:32:09

© Université de Strasbourg/CNRS

    • Contact