2011A&A...528A.119D


Query : 2011A&A...528A.119D

2011A&A...528A.119D - Astronomy and Astrophysics, volume 528A, 119-119 (2011/4-1)

Deep wide-field imaging down to the oldest main sequence turn-offs in the Sculptor dwarf spheroidal galaxy.

DE BOER T.J.L., TOLSTOY E., SAHA A., OLSEN K., IRWIN M.J., BATTAGLIA G., HILL V., SHETRONE M.D., FIORENTINO G. and COLE A.

Abstract (from CDS):

We present wide-field photometry of resolved stars in the nearby Sculptor dwarf spheroidal galaxy using CTIO/MOSAIC, going down to the oldest main sequence turn-off. The accurately flux calibrated wide field colour-magnitude diagrams can be used to constrain the ages of different stellar populations, and also their spatial distribution. The Sculptor dSph contains a predominantly ancient stellar population (>10Gyr old) which can be easily resolved into individual stars. A galaxy dominated by an old population provides a clear view of ancient processes of galaxy formation unimpeded by overlying younger populations. By using spectroscopic metallicities of RGB stars in combination with our deep main sequence turn-off photometry we can constrain the ages of different stellar populations with particular accuracy. We find that the known metallicity gradient in Sculptor is well matched to an age gradient. This is the first time that this link with age has been directly quantified. This gradient has been previously observed as a variation in horizontal branch properties and is now confirmed to exist for main sequence turn-offs as well. It is likely the Sculptor dSph first formed an extended metal-poor population at the oldest times, and subsequent more metal-rich, younger stars were formed more towards the centre until the gas was depleted or lost roughly 7Gyr ago. The fact that these clear radial gradients have been preserved up to the present day is consistent with the apparent lack of signs of recent tidal interactions.

Abstract Copyright:

Journal keyword(s): galaxies: dwarf - galaxies: evolution - galaxies: stellar content - Local Group - Hertzsprung-Russell and C-M diagrams

Simbad objects: 18

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Number of rows : 18
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 JL 163 HS? 00 10 33.2208208992 -50 15 24.389869392   12.72 12.89     sdB: 10 0
2 NAME Sculptor Field reg 00 22 48 -30 06.5           ~ 15 0
3 V* T Phe Mi* 00 30 26.2337742744 -46 24 33.379722396   12.46 11.43 12.43   M7e 68 0
4 SA 92- reg 00 55 03.80 +00 47 13.2           ~ 99 0
5 NAME Sculptor Dwarf Galaxy G 01 00 09.4 -33 42 32   9.79 8.6 8.81   ~ 1242 4
6 PG 0231+051 WD* 02 33 41.3574299856 +05 18 43.649856216 14.562 15.776 16.096 16.267 16.639 DAO.6 144 0
7 SA 95- reg 03 53 21.0 -00 01 10           ~ 83 0
8 CD-40 1200 * 04 03 05.1949768272 -40 11 02.904102528   11.25 10.62     ~ 4 0
9 LB 1735 HS* 04 31 11.0906802672 -53 35 27.081336228 12.90 13.49 13.66     sdOB 12 0
10 1RXS J055156.4-491458 X 05 51 56.4 -49 14 58           ~ 2 0
11 RX J0831.7-5341 WD* 08 31 51.9100703544 -53 40 32.516592636   14.6 14.5 14.6   DA1.6 34 0
12 SA 101- reg 09 57 28.2 -00 19 39           ~ 74 0
13 LSE 259 HS* 16 53 54.5759529408 -56 01 54.753819672     12.54     sdO 31 0
14 BPS CS 22943-0127 HS* 20 22 49.0574012568 -43 30 11.525000436 12.29 13.41 13.63 13.99   sdO 10 0
15 JL 82 HS* 21 36 01.2957494184 -72 48 27.222290172 11.26 12.44 12.41 12.67   sdB 33 0
16 PG 2213-006 HS* 22 16 28.3762385784 -00 21 13.503339864 12.747 13.93 14.14 14.54 14.348 sdOB 76 0
17 JL 117 HS* 22 54 38.0014828488 -72 23 09.728883276 12.86 14.12 14.49     sdO 10 0
18 NAME Local Group GrG ~ ~           ~ 7720 0

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2022.08.10-19:37:18

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