2014A&A...566A..44B


C.D.S. - SIMBAD4 rel 1.7 - 2019.10.18CEST04:48:17

2014A&A...566A..44B - Astronomy and Astrophysics, volume 566A, 44-44 (2014/6-1)

The extended structure of the dwarf irregular galaxies Sextans A and Sextans B. Signatures of tidal distortion in the outskirts of the Local Group.

BELLAZZINI M., BECCARI G., FRATERNALI F., OOSTERLOO T.A., SOLLIMA A., TESTA V., GALLETI S., PERINA S., FACCINI M. and CUSANO F.

Abstract (from CDS):

We present a detailed study of the stellar and HI structure of the dwarf irregular galaxies Sextans A and Sextans B, members of the NGC 3109 association. We use newly obtained deep (r≃26.5) and wide-field g and r photometry to extend the surface brightness (SB) profiles of the two galaxies down to µV≃31.0mag/arcsec2. We find that both galaxies are significantly more extended than previously traced with surface photometry, out to ∼4kpc from their centres along their major axes. Older stars are found to have more extended distribution than younger populations. We obtain the first estimate of the mean metallicity for the old stars in Sex B, from the colour distribution of the red giant branch, <[Fe/H]≥-1.6. The SB profiles show significant changes of slope and cannot be fitted with a single Sersic model. Both galaxies have HI discs as massive as their respective stellar components. In both cases the HI discs display solid-body rotation with maximum amplitude of ∼50km/s (albeit with significant uncertainty due to the poorly constrained inclination), implying a dynamical mass ∼109M, a mass-to-light ratio (M)/(LV)∼25, and a dark-to-baryonic mass ratio of ∼10. The distribution of the stellar components is more extended than the gaseous disc in both galaxies. We find that the main, approximately round, stellar body of Sex A is surrounded by an elongated low-SB stellar halo that can be interpreted as a tidal tail, similar to that found in another member of the same association (Antlia). We discuss these, as well as other evidence of tidal disturbance, in the framework of a past passage of the NGC 3109 association close to the Milky Way, which has been hypothesised by several authors and is also supported by the recently discovered filamentary configuration of the association itself.

Abstract Copyright:

Journal keyword(s): galaxies: dwarf - Local Group - galaxies: structure - galaxies: ISM - galaxies: stellar content

VizieR on-line data: <Available at CDS (J/A+A/566/A44): sex_a.dat sex_b.dat>

Status in Simbad:  will not be processed

Simbad objects: 14

goto Full paper

goto View the reference in ADS

Number of rows : 14

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2019
#notes
1 IC 10 G 00 20 23.16 +59 17 34.7   13.6 9.5     ~ 981 0
2 M 31 G 00 42 44.330 +41 16 07.50 4.86 4.36 3.44     ~ 10562 1
3 NAME Magellanic Clouds GrG 03 00 -71.0           ~ 5375 1
4 UGC 4879 G 09 16 02.0197873600 +52 50 42.052874443   14.0 13.2     ~ 98 0
5 NAME Leo Dwarf Irregular Galaxy G 09 59 26.46 +30 44 47.0 14.08 13.54 13.26 13.33   ~ 535 0
6 NAME NGC 3109 Group GrG 09 59 35.2 -12 49 52           ~ 31 0
7 NAME Sextans B H2G 10 00 00.8201300945 +05 20 09.572530884 12.77 12.25 11.89 11.71   ~ 454 0
8 NGC 3109 G 10 03 06.877 -26 09 34.46 11.10 10.42 10.04 9.91   ~ 679 2
9 NAME Sex A H2G 10 11 00.5 -04 41 30 12.48 12.13 11.93 11.78   ~ 637 2
10 TYC 4907-713-1 * 10 11 04.1537068500 -04 40 54.402653329   13.09 11.50 11.03 10.02 ~ 1 0
11 NAME Leo P BiC 10 21 45.123 +18 05 16.89           ~ 138 0
12 M 3 GlC 13 42 11.62 +28 22 38.2     6.39     ~ 2223 0
13 M 92 GlC 17 17 07.39 +43 08 09.4     6.52     ~ 1864 0
14 NAME Local Group GrG ~ ~           ~ 6660 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2014A&A...566A..44B and select 'bookmark this link' or equivalent in the popup menu


2019.10.18-04:48:17

© Université de Strasbourg/CNRS

    • Contact