Chemical and kinematical properties of Galactic bulge stars surrounding the stellar system Terzan 5
| Autor: | Rodrigo A. Ibata, Emanuele Dalessandro, L. Lovisi, Davide Massari, Alessio Mucciarelli, R. M. Rich, Francesco R. Ferraro, Livia Origlia, Barbara Lanzoni, Michele Bellazzini, David Reitzel |
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| Přispěvatelé: | D. Massari, A. Mucciarelli, F. R. Ferraro, L. Origlia, R. M. Rich, B. Lanzoni, E. Dalessandro, R. Ibata, L. Lovisi, M. Bellazzini, D. Reitzel |
| Rok vydání: | 2014 |
| Předmět: |
010504 meteorology & atmospheric sciences
Metallicity Population FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Spectral line Bulge 0103 physical sciences Galaxy: globular clusters: general Astrophysics::Solar and Stellar Astrophysics education 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences Physics education.field_of_study Astronomy and Astrophysics Astrophysics - Astrophysics of Galaxies Galaxy Radial velocity Stars Star cluster Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Astrophysics::Earth and Planetary Astrophysics |
| DOI: | 10.48550/arxiv.1407.0047 |
| Popis: | As part of a study aimed at determining the kinematical and chemical properties of Terzan 5, we present the first characterization of the bulge stars surrounding this puzzling stellar system. We observed 615 targets located well beyond the tidal radius of Terzan 5 and we found that their radial velocity distribution is well described by a Gaussian function peaked at =+21.0\pm4.6 km/s and with dispersion sigma_v=113.0\pm2.7 km/s. This is the one of the few high-precision spectroscopic survey of radial velocities for a large sample of bulge stars in such a low and positive latitude environment (b=+1.7{\deg}). We found no evidence for the peak at \sim+200 km/s found in Nidever et al. 2012. The strong contamination of many observed spectra by TiO bands prevented us from deriving the iron abundance for the entire spectroscopic sample, introducing a selection bias. The metallicity distribution was finally derived for a sub-sample of 112 stars in a magnitude range where the effect of the selection bias is negligible. The distribution is quite broad and roughly peaked at solar metallicity ([Fe/H]\simeq+0.05 dex) with a similar number of stars in the super-solar and in the sub-solar ranges. The population number ratios in different metallicity ranges agree well with those observed in other low-latitude bulge fields suggesting (i) the possible presence of a plateau for |b Comment: 27 pages, 9 figures, accepted for publication by ApJ |
| Databáze: | OpenAIRE |
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