2017A&A...599A.125F


Query : 2017A&A...599A.125F

2017A&A...599A.125F - Astronomy and Astrophysics, volume 599A, 125-125 (2017/3-1)

Weak Galactic halo-Fornax dSph connection from RR Lyrae stars.

FIORENTINO G., MONELLI M., STETSON P.B., BONO G., GALLART C., MARTINEZ-VAZQUEZ C.E., BERNARD E.J., MASSARI D., BRAGA V.F. and DALL'ORA M.

Abstract (from CDS):

Aims. For the first time accurate pulsation properties of the ancient variable stars of the Fornax dwarf spheroidal galaxy (dSph) are discussed in the broad context of galaxy formation and evolution.
Methods. Homogeneous multi-band BVI optical photometry of spanning twenty years has allowed us to identify and characterize more than 1400 RR Lyrae stars (RRLs) in this galaxy.
Results. Roughly 70% are new discoveries. We investigate the period-amplitude distribution and find that Fornax shows a lack of high amplitude (AV≳0.75mag) short period fundamental-mode RRLs (P≤0.48d, HASPs). These objects occur in stellar populations more metal-rich than [Fe/H]~-1.5 and they are common in the Galactic halo (hereafter Halo) and in globulars. This evidence suggests that old Fornax stars (older than 10Gyr) are relatively metal poor. A detailed statistical analysis of the role of the present-day Fornax dSph in reproducing the Halo period distribution shows that it can only account for up to 20% of the Halo when combined with RRLs in massive dwarf galaxies (Sagittarius dSph, Large Magellanic Cloud). This finding indicates that Fornax-like systems played a smaller role than massive dwarfs in building up the Halo.
Conclusions. We also discuss the occurrence of HASPs in connection with the luminosity and the early chemical composition of nearby dwarf galaxies. We find that, independently of their individual star formation histories, bright (MV≤-13.5mag) galaxies have HASPs, whereas faint ones (MV≳-11mag) do not. Interestingly enough, Fornax belongs to a luminosity range (-11<MV≤-13.5mag) in which the occurrence of HASPs appears to be correlated with the early star formation and chemical enrichment of the host galaxy.

Abstract Copyright: © ESO, 2017

Journal keyword(s): galaxies: evolution - galaxies: individual: Fornax dSph - stars: variables: RR Lyrae - stars: variables: RR Lyrae

Simbad objects: 21

goto Full paper

goto View the references in ADS

Number of rows : 21
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 NGC 147 GiG 00 33 12.120 +48 30 31.46   12.0 9.5     ~ 637 1
2 NGC 185 Sy2 00 38 57.970 +48 20 14.56   9.10 9.2     ~ 745 1
3 M 32 IG 00 42 41.825 +40 51 54.61 9.51 9.03 8.08     ~ 2044 2
4 M 31 G 00 42 44.330 +41 16 07.50 4.86 4.36 3.44     ~ 11375 1
5 NAME Andromeda I G 00 45 39.8 +38 02 28   13.9 12.7     ~ 315 0
6 NAME SMC G 00 52 38.0 -72 48 01   2.79 2.2     ~ 9858 1
7 NAME Scl Group GrG 01 00 06 -33 44.2           ~ 472 0
8 NAME Andromeda II G 01 16 29.8 +33 25 09     11.7     ~ 355 0
9 NAME Fornax Dwarf Spheroidal G 02 39 59.3 -34 26 57   9.02 7.4     ~ 1553 1
10 NAME Magellanic Clouds GrG 03 00 -71.0           ~ 5995 1
11 ACO S 373 ClG 03 38 30 -35 27.3           ~ 1624 0
12 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 15466 1
13 NAME Leo T G 09 34 53.4 +17 03 05     15.1     ~ 325 0
14 NAME Leo Dwarf Irregular Galaxy G 09 59 26.46 +30 44 47.0 14.08 13.54 13.26 13.33   ~ 561 0
15 NAME Leo I dSph G 10 08 28.12 +12 18 23.4   11.3 10.0     ~ 1096 1
16 NAME SDG G 18 55 03.1 -30 28 42   4.5 3.6     ~ 1861 2
17 NAME Aquarius Dwarf G 20 46 51.7 -12 50 54 15.75 15.18 14.83 14.46   ~ 407 1
18 NAME Andromeda VII GiG 23 26 31.7 +50 40 33   13.6 11.8     ~ 188 1
19 V* SX Phe SX* 23 46 32.8929064612 -41 34 54.770795675   7.40 7.12     A3V 318 0
20 NAME Peg dSph GiG 23 51 46.4 +24 35 11   14.5 13.2     ~ 223 2
21 NAME Local Group GrG ~ ~           ~ 7318 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2017A&A...599A.125F and select 'bookmark this link' or equivalent in the popup menu


2021.07.30-00:05:04

© Université de Strasbourg/CNRS

    • Contact