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J/A+A/605/A46    Sgr dSph nucleus stars chemical abundances (Mucciarelli+, 2017)

Chemical abundances in the nucleus of the Sagittarius dwarf spheroidal galaxy. Mucciarelli A., Bellazzini M., Ibata R., Romano D., Chapman S.C., Monaco L. <Astron. Astrophys. 605, A46 (2017)> =2017A&A...605A..46M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra ; Stars, population II ; Abundances Keywords: galaxies: dwarf - galaxies: Local Group - galaxies: stellar content - stars: abundances Abstract: We present Iron, Magnesium, Calcium, and Titanium abundances for 235 stars in the central region of the Sagittarius dwarf spheroidal galaxy (within 9.0'~=70pc from the center) from medium-resolution Keck/DEIMOS spectra. All the considered stars belong to the massive globular cluster M 54 or to the central nucleus of the galaxy (Sgr,N). In particular we provide abundances for 109 stars with [Fe/H]≥-1.0, more than doubling the available sample of spectroscopic metallicity and α-elements abundance estimates for Sgr dSph stars in this metallicity regime. We find for the first time a metallicity gradient in the Sgr,N population, whose peak iron abundance goes from [Fe/H]=-0.38 for R≤2.5' to [Fe/H]=-0.57 for 5.0<R≤9.0 arcmin. On the other hand the trends of [Mg/Fe], [Ca/Fe], and [Ti/Fe] with [Fe/H] are the same over the entire region explored by our study. We reproduce the observed chemical patterns of the Sagittarius dwarf spheroidal as a whole with a chemical evolution model implying a high mass progenitor (MDM=6x1010M) and a significant event of mass-stripping occurred a few Gyr ago, presumably starting at the first peri-Galactic passage after infall. Description: Abundance ratios for iron, magnesium, calcium and titanium of 235 giant stars in the central region of the Sagittarius dwarf spheroidal galaxy. Coordinates and atmospheric parameters (effective temperature, surface gravities and microturbulent velocities) are provided. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 117 235 Atmospheric parameters and abundance ratios
See also: J/A+A/459/777 : X-ray sources in Sagittarius & Carina dSph (Cignoni+, 2006) J/A+A/465/815 : Abundances of Sgr dSph stars (Sbordone+, 2007) J/A+A/513/A62 : Sgr dSph VIMOS photometry & RV (Giuffrida+, 2010) J/A+A/520/A95 : M54 and Sgr dSph red giants abundances (Carretta+, 2010) J/ApJ/756/74 : 2MASS view of Sgr dSph. VII. Kinematics (Frinchaboy+, 2012) J/AJ/145/163 : Catalog of stars in Sgr dwarf galaxy (Newby+, 2013) J/MNRAS/444/1812 : M54 red giants abundances (Mucciarelli+, 2014) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 7 I7 --- ID [1500190/4210645] Identification number 11- 20 F10.6 deg RAdeg Right ascension (J2000) 24- 33 F10.6 deg DEdeg Declination (J2000) 37- 40 I4 K Teff Effective temperature 44- 47 F4.2 [cm/s2] log(g) Surface gravity 51- 53 F3.1 km/s vt Microturbulent velocity 57- 61 F5.2 [Sun] [Fe/H] Relative abundance [Fe/H] 66- 69 F4.2 [Sun] e_[Fe/H] Uncertainty on [Fe/H] 73- 77 F5.2 [Sun] [Mg/Fe] ?=99.99 Relative abundance [Mg/Fe] 82- 85 F4.2 [Sun] e_[Mg/Fe] ?=0 Uncertainty on [Mg/Fe] 89- 93 F5.2 [Sun] [Ca/Fe] Relative abundance [Ca/Fe] 98-101 F4.2 [Sun] e_[Ca/Fe] Uncertainty on [Ca/Fe] 105-109 F5.2 [Sun] [Ti/Fe] ?=99.99 Relative abundance [Ti/Fe] 114-117 F4.2 [Sun] e_[Ti/Fe] ?=0 Uncertainty on [Ti/Fe]
Acknowledgements: Alessio Mucciarelli, alessio.mucciarelli2(at)unibo.it
(End) Patricia Vannier [CDS] 19-May-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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