CDS Portal Simbad VizieR Aladin X-Match Other Help J/A+A/590/A9 RGB stars in Galactic GC stellar parameters (Dias+, 2016) FORS2/VLT survey of Milky Way globular clusters. II. Fe and Mg abundances of 51 Milky Way globular clusters on a homogeneous scale. Dias B., Barbuy B., Saviane I, Held E., Da Costa G., Ortolani S., Gullieuszik M., Vasquez S. =2016A&A...590A...9D (SIMBAD/NED BibCode) ADC_Keywords: Milky Way ; Clusters, globular ; Stars, giant ; Abundances ; Radial velocities ; Spectroscopy ; Effective temperatures ; Models, atmosphere Keywords: stars: abundances - stars: kinematics and dynamics - stars: Population II - Galaxy: stellar content - Galaxy: evolution - globular clusters: general Abstract: Globular clusters trace the formation and evolution of the Milky Way and surrounding galaxies, and outline their chemical enrichment history. To accomplish these tasks it is important to have large samples of clusters with homogeneous data and analysis to derive kinematics, chemical abundances, ages and locations. We aim to obtain homogeneous metallicities and alpha-element enhancement for 51 Galactic bulge, disc, and halo globular clusters that are among the most distant and/or highly reddened in the Galaxy's globular cluster system. We also provide membership selection based on stellar radial velocities and atmospheric parameters. The implications of our results are discussed. We observed R∼2000 spectra in the wavelength interval 456-586nm for over 800 red giant stars in 51 Galactic globular clusters. We applied full spectrum fitting with the code ETOILE together with libraries of observed and synthetic spectra. We compared the mean abundances of all clusters with previous work and with field stars. We used the relation between mean metallicity and horizontal branch morphology defined by all clusters to select outliers for discussion. [Fe/H], [Mg/Fe], and [alpha/Fe] were derived in a consistent way for almost one-third of all Galactic globular clusters. We find our metallicities are comparable to those derived from high-resolution data to within sigma=0.08dex over the interval -2.5<[Fe/H]<0.0. Further, a comparison of previous metallicity scales with ours yields sigma<0.16dex. We also find that the distribution of [Mg/Fe] and [alpha/Fe] with [Fe/H] for the 51 clusters follows the general trend exhibited by field stars. It is the first time that the following clusters are included in a large sample of homogeneous stellar spectroscopic observations and metallicity derivation: BH 176, Djorg 2, Pal 10, NGC 6426, Lynga 7, and Terzan 8. In particular, the first three clusters only had photometric metallicities previously and the available metallicity for NGC 6426 was based only on integrated spectroscopy and photometry. Two other clusters, HP 1 and NGC 6558, are confirmed as candidates for the oldest globular clusters in the Milky Way. Stellar spectroscopy in the visible at R∼2000 for a large sample of globular clusters is a robust and efficient way to trace the chemical evolution of the host galaxy and to detect interesting objects for follow-up at higher-resolution and with forthcoming giant telescopes. The technique used here can also be applied to globular cluster systems in nearby galaxies with current instruments and to distant galaxies with the advent of ELTs. Description: Spectroscopic parameters for 758 red giant branch stars in 51 Milky Way globular clusters. For each star star ID, cluster name, equatorial coordinates, magnitude, colour, heliocentric velocities, membership classification member, effective temperature, surface gravity, metallicity, Mg and alpha-element abundance. We note that magnitude and colours are not calibrated. File Summary: FileName Lrecl Records Explanations ReadMe 80 . This file table1.dat 115 758 Identification of cluster stars including photometric and kinematics information tablea2.dat 126 758 Atmospheric parameters for RGB stars See also: J/A+A/540/A27 : Spectroscopy in Galactic globular clusters (Saviane+, 2012) J/A+A/573/A13 : Metal abundances in 6 globular cluster (Dias+, 2015) Byte-by-byte Description of file: table1.dat Bytes Format Units Label Explanations 1- 13 A13 --- Star Star identification (G1) 15- 21 A7 --- Cl.ID Cluster identification 23- 33 A11 --- Cl.Name Cluster name 35- 44 F10.6 deg RAdeg Right ascension (J2000) 46- 55 F10.6 deg DEdeg Declination (J2000) 57- 58 I2 h RAh Right ascension (J2000.0) 60- 61 I2 min RAm Right ascension (J2000.0) 63- 66 F4.1 s RAs Right ascension (J2000.0) 68 A1 --- DE- Declination sign (J2000.0) 69- 70 I2 deg DEd Declination (J2000.0) 72- 73 I2 arcmin DEm Declination (J2000.0) 75- 78 F4.1 arcsec DEs Declination (J2000.0) 80- 84 F5.2 mag Vmag V magnitude (2) 86- 91 F6.3 mag V-I ? V-I colour index (2) 93- 98 F6.3 mag B-V ? B-V colour index (2) 100-103 I4 km/s HV Heliocentric velocity 105-113 F9.4 km/s HVt ? Heliocentric velocity from CaT (3) 115 A1 --- Mmb [M] Membership (M=member) Note (2): magnitudes and colours are not calibrated, they were used to select the targets from the red giant branch in the pre-images. Note (3): The velocities from CaT were taken from from Saviane et al. (2012A&A...540A..27S, Cat. J/A+A/540/A27) and from Vasquez et al. (in prep.) Byte-by-byte Description of file: tablea2.dat Bytes Format Units Label Explanations 1- 13 A13 --- Star Star identification (G1) 15- 18 I4 K TeffM Effective temperature from MILES library 20- 22 I3 K e_TeffM rms uncertainty on TeffM 24- 27 I4 K TeffC Effective temperature from Coelho library 29- 31 I3 K e_TeffC rms uncertainty on TeffM 33- 36 I4 K Teff Average of MILES and Coelho effective temperature (adopted) 38- 40 I3 K e_Teff rms uncertainty on Teff 42- 45 F4.2 [cm/s2] loggM Surface gravity from MILES library 47- 50 F4.2 [cm/s2] e_loggM rms uncertainty on loggM 52- 55 F4.2 [cm/s2] loggC Surface gravity from Coelho library 57- 60 F4.2 [cm/s2] e_loggC rms uncertainty on loggC 62- 65 F4.2 [cm/s2] logg Average of MILES and Coelho surface gravity 67- 70 F4.2 [cm/s2] e_logg rms uncertainty on loggC 72- 76 F5.2 [Sun] [Fe/H]M Metallicity from MILES library 78- 81 F4.2 [Sun] e_[Fe/H]M rms uncertainty on [Fe/H]M 83- 87 F5.2 [Sun] [Fe/H]C Metallicity from Coelho library 89- 92 F4.2 [Sun] e_[Fe/H]C rms uncertainty on [Fe/H]C 94- 98 F5.2 [Sun] [Fe/H] Average of MILES and Coelho metallicity 100-103 F4.2 [Sun] e_[Fe/H] rms uncertainty on [Fe/H] 105-109 F5.2 [Sun] [Mg/Fe] Abundance [Mg/Fe] rom MILES library 111-114 F4.2 [Sun] e_[Mg/Fe] rms uncertainty on [Mg/Fe] 116-119 F4.2 [Sun] [a/Fe] Abundance [alpha/Fe] from Coelho library 121-124 F4.2 [Sun] e_[a/Fe] rms uncertainty on [alpha/Fe] 126 A1 --- Mmb [M] Membership (M=member) Global notes: Note (G1): Stars identified as Cl.Name_NNN (as example 47Tuc_502). Acknowledgements: Ivo Saviane, isaviane(at)eso.org and Sergio Vasquez, svasquez(at)astro.puc.cl References: Saviane et al., 2012A&A...540A..27S, Cat. J/A+A/540/A27 Homogeneous metallicities and radial velocities for Galactic globular clusters. First CaT metallicities for twenty clusters Vasquez et al., 2016, in prep. Homogeneous Metallicities and Radial Velocities for Galactic Globular Clusters. II New CaT metallicities for 28 faint and redden globular clusters Dias et al., 2015A&A...573A..13D, Cat. J/A+A/573/A13 FORS2/VLT survey of Milky Way globular clusters. I. Description of the method for derivation of metal abundances in the optical and application to NGC 6528, NGC 6553, M 71, NGC 6558, NGC 6426, and Terzan 8. (End) Bruno Dias [ESO, Chile], Patricia Vannier [CDS] 10-Mar-2016 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 © Université de Strasbourg/CNRS • Contact