J/A+A/669/A54 Sgr dSph members RV and [Fe/H] (Minelli+, 2023)
The metallicity distribution in the core of the Sagittarus dwarf spheroidal:
Minimising the metallicity biases.
Minelli A., Bellazzini M., Mucciarelli A., Bonifacio P., Ibata R.,
Romano D., Monaco L., Caffau E., Dalessandro E., Pascale R.
<Astron. Astrophys. 669, A54 (2023)>
=2023A&A...669A..54M 2023A&A...669A..54M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Populations, stellar ; Radial velocities ;
Abundances, [Fe/H] ; Photometry ; Optical ; Effective temperatures
Keywords: stars: abundances - galaxies: evolution - Local Group -
galaxies: dwarf - techniques: spectroscopic
Abstract:
We present the metallicity and radial velocity for 450 bona fide
members of the Sagittarius dwarf spheroidal (Sgr dSph) galaxy,
measured from high-resolution spectra (R∼18000) obtained with FLAMES
at the VLT. The targets were carefully selected (a) to sample the core
of the main body of Sgr dSph while avoiding contamination from the
central stellar nucleus, and (b) to prevent any bias on the
metallicity distribution by selecting targets based on their Gaia
parallax and proper motions. All the targets selected in this way were
confirmed as radial velocity members. We used this sample to derive
the first metallicity distribution of the core of Sgr dSph which is
virtually unaffected by metallicity biases. The observed distribution
ranges from [Fe/H]~-2.3 to [Fe/H]∼0.0, with a strong, symmetric, and
relatively narrow peak around [Fe/H]~-0.5 and a weak and extended
metal-poor tail, in which only 13.8±1.9% of the stars have
[Fe/H]←1.0. We confirm previous evidence of correlations between
chemical and kinematical properties of stars in the core of Sgr. In
our sample, stars with [Fe/H]≥-0.6 display a lower velocity
dispersion and a higher rotation amplitude than those with
[Fe/H]←0.6, confirming previous suggestions of disk/halo structure
for the progenitor of the system.
Description:
Table 1 : Main parameters of the target stars: Gaia DR3 identification
number, coordinates, G, BP and RP magnitudes, Atmospheric parameters,
radial velocities and metallicity with corresponding errors.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 92 450 Main parameters of the targets
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR3 Gaia DR3 identification number
21- 29 F9.5 deg RAdeg Right ascension (J2000)
31- 39 F9.5 deg DEdeg Declination (J2000)
41- 45 F5.2 mag Gmag Gaia G magnitude
47- 51 F5.2 mag BPmag Gaia BP magnitude
53- 57 F5.2 mag RPmag Gaia RP magnitude
59- 62 I4 K Teff Effective temperature
64- 67 F4.2 [cm/s2] logg Surface gravity
69- 71 F3.1 km/s vt Microturbulent velocity
73- 77 F5.1 km/s RV Radial velocity
79- 81 F3.1 km/s e_RV Uncertainty on RV
83- 87 F5.2 [Sun] [Fe/H] Relative abundance [Fe/H]
89- 92 F4.2 [Sun] e_[Fe/H] Uncertainty on [Fe/H]
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Acknowledgements:
Alice Minelli, alice.minelli4(at)unibo.it
(End) Patricia Vannier [CDS] 23-Nov-2022