Sulfur abundances in the Galactic bulge and disk
Abstract
Context. The measurement of α-element abundances provides a powerful tool for placing constraints on the chemical evolution and star formation history of galaxies. The majority of studies on the α-element sulfur (S) are focused on local stars, making S behavior in other environments an astronomical topic that is yet to be explored in detail.
Aims: The investigation of S in the Galactic bulge was recently considered for the first time. This work aims to improve our knowledge on S behavior in this component of the Milky Way.
Methods: We present the S abundances of 74 dwarf and sub-giant stars in the Galactic bulge, along with 21 and 30 F and G thick- and thin-disk stars, respectively. We performed a local thermodynamic equilibrium analysis and applied corrections for non-LTE on high resolution and high signal-to-noise UVES spectra. S abundances were derived from multiplets 1, 6, and 8 in the metallicity range of − 2 < [Fe/H] < 0.6, by spectrosynthesis or line equivalent widths.
Results: We confirm that the behavior of S resembles that of an α-element within the Galactic bulge. In the [S/Fe] versus [Fe/H] diagram, S presents a plateau at low metallicity, followed by a decreasing of [S/Fe] with the increasing of [Fe/H], before reaching [S/Fe] ~ 0 at a super-solar metallicity. We found that the Galactic bulge is S-rich with respect to both the thick- and thin-disks at − 1 < [Fe/H] < 0.3, supporting a scenario of more rapid formation and chemical evolution in the Galactic bulge than in the disk.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 2022
- DOI:
- 10.1051/0004-6361/202140947
- arXiv:
- arXiv:2109.06216
- Bibcode:
- 2022A&A...657A..29L
- Keywords:
-
- stars: abundances;
- Galaxy: bulge;
- Galaxy: disk;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 14 pages, 9 figures, 4 tables