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 (20)

• A Relationship Between Stellar Metallicity Gradients and Galaxy Age in Dwarf Galaxies
• The star formation history of the Sculptor dwarf spheroidal galaxy
• The stellar metallicity gradients of Local Group dwarf galaxies
• The infall of dwarf satellite galaxies are influenced by their host's massive accretions
• The Tucana dwarf spheroidal galaxy: not such a massive failure after all
• Internal rotation of Milky Way dwarf spheroidal satellites with $Gaia$ Early Data Release 3
• How much metals did the first stars provide to the ultra-faint dwarfs?
• Extremely metal-poor stars in the Fornax and Carina dwarf spheroidal galaxies
• External Enrichment of Minihalos by the First Supernovae
• Homogeneity in the early chemical evolution of the Sextans dwarf Spheroidal galaxy
• Tidally induced velocity gradients in the Milky Way dwarf spheroidal satellites
• Binary star population of the Sculptor dwarf galaxy
• Neutron-capture elements in dwarf galaxies III: A homogenized analysis of 13 dwarf spheroidal and ultra-faint galaxies
• 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
• The THESAN project: environmental drivers of Local Group reionization
• Investigating the Impacts of AGN Activities on Dwarf Galaxies with FAST HI Observations