The star formation history of the Sextans dwarf spheroidal galaxy: a true fossil of the pre-reionization era

Abstract

We present the star formation history (SFH) of the Sextans dwarf spheroidal galaxy based on deep archive $B$,$I$ photometry taken with Suprime-Cam at Subaru telescope focusing our analysis on the inner region of the galaxy, fully located within the core radius. Within the errors of our SFH we have not detected any metallicity gradient along the considered radial distance interval. As a main result of this work we can state that the Sextans dwarf spheroidal stopped forming stars less than $\sim 1.3$ Gyr after Big Bang in correspondance to the end of the reionization epoch. We have been able to constrain the duration of the main burst of star formation to $\sim 0.6$ Gyr. From the calculation of the mechanical luminosity released from supernovae (SNe) during the brief episode of star formation, there are strong indications that SNe could have played an important role in the fate of Sextans, by removing almost completely the gas component, so preventing a prolonged star formation.

11 pages, 10 figures. Accepted for publication in MNRAS

References in corpus (7)

• A common mass scale for satellite galaxies of the Milky Way
• New Grids of ATLAS9 Model Atmospheres
• Subaru Deep Survey V. A Census of Lyman Break Galaxies at z=4 and 5 in the Subaru Deep Fields: Photometric Properties
• The Star Formation Histories of Local Group Dwarf Galaxies II. Searching For Signatures of Reionization
• Multi-Element Abundance Measurements from Medium-Resolution Spectra. IV. Alpha Element Distributions in Milky Way Dwarf Satellite Galaxies
• The mass and velocity anisotropy of the Carina, Fornax, Sculptor and Sextans dwarf spheroidal galaxies
• Population gradient in Sextans dSph: Comprehensive mapping of a dwarf galaxy by Suprime-Cam

Cited by in corpus (7)

• The star formation history of the Sculptor dwarf spheroidal galaxy
• Binary star population of the Sculptor dwarf galaxy
• A segmented period-luminosity relation for nearby extragalactic $\delta$ Scuti stars
• A Possible Relic Star Cluster in the Sextans Dwarf Galaxy
• The Gas Accretion History of Low Mass Halos within the Cosmic Web from Cosmological Simulations
• Star Formation Histories of Dwarf Spheroidal and Dwarf Elliptical Galaxies in the Local Universe
• The impact of rare events on the chemical enrichment in dwarf galaxies