Navigation auf zora.uzh.ch

Search

ZORA (Zurich Open Repository and Archive)

The Star Formation History of Eridanus II: On the Role of Supernova Feedback in the Quenching of Ultrafaint Dwarf Galaxies

Gallart, C; Monelli, M; Ruiz-Lara, T; Calamida, A; Cassisi, S; Cignoni, M; Anderson, J; Battaglia, G; Bermejo-Climent, J R; Bernard, E J; Martínez-Vázquez, C E; Mayer, L; Salvadori, S; Monachesi, A; Navarro, J F; Shen, S; Surot, F; Tosi, M; Bajaj, V; Strinfellow, G S (2021). The Star Formation History of Eridanus II: On the Role of Supernova Feedback in the Quenching of Ultrafaint Dwarf Galaxies. The Astrophysical Journal, 909(2):192.

Abstract

Eridanus II (Eri II) is an ultrafaint dwarf (UFD) galaxy (MV = −7.1) located at a distance close to the Milky Way virial radius. Early shallow color–magnitude diagrams (CMDs) indicated that it possibly hosted an intermediate-age or even young stellar population, which is unusual for a galaxy of this mass. In this paper, we present new Hubble Space Telescope/Advanced Camera for Surveys CMDs reaching the oldest main-sequence turnoff with excellent photometric precision and derive a precise star formation history (SFH) for this galaxy through CMD fitting. This SFH shows that the bulk of the stellar mass in Eri II formed in an extremely short star formation burst at the earliest possible time. The derived star formation rate profile has a width at half maximum of 500 Myr and reaches a value compatible with null star formation 13 Gyr ago. However, tests with mock stellar populations and with the CMD of the globular cluster M92 indicate that the star formation period could be shorter than 100 Myr. From the quantitative determination of the amount of mass turned into stars in this early star formation burst ( ∼2 × 105 M⊙) we infer the number of supernova (SN) events and the corresponding energy injected into the interstellar medium. For reasonable estimates of the Eri II virial mass and values of the coupling efficiency of the SN energy, we conclude that Eri II could be quenched by SN feedback alone, thus casting doubts on the need to invoke cosmic reionization as the preferred explanation for the early quenching of old UFD galaxies.

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Institute for Computational Science
Dewey Decimal Classification:530 Physics
Scopus Subject Areas:Physical Sciences > Astronomy and Astrophysics
Physical Sciences > Space and Planetary Science
Uncontrolled Keywords:Space and Planetary Science, Astronomy and Astrophysics
Language:English
Date:1 March 2021
Deposited On:11 Feb 2022 07:37
Last Modified:27 Aug 2024 01:38
Publisher:IOP Publishing
ISSN:1538-4357
OA Status:Closed
Free access at:Publisher DOI. An embargo period may apply.
Publisher DOI:https://doi.org/10.3847/1538-4357/abddbe

Metadata Export

Statistics

Citations

Dimensions.ai Metrics
21 citations in Web of Science®
25 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

0 downloads since deposited on 11 Feb 2022
0 downloads since 12 months

Authors, Affiliations, Collaborations

Similar Publications