The star formation history of the Sculptor dwarf spheroidal galaxy

Journal Article · 19 June 2019 · Monthly Notices of the Royal Astronomical Society

DOI: https://doi.org/10.1093/mnras/stz1679 · OSTI ID:1531037

Bettinelli, M.  ^[1]; Hidalgo, S. L. ^[2]; Cassisi, S. ^[3]; Aparicio, A. ^[2]; Piotto, G. ^[4]; Valdes, F. ^[5]; Walker, A. R. ^[6]

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1. Instituto de Astrofìsica de Canarias, Vìa Làctea S/N, E-38200 La Laguna, Tenerife, Spain, Department of Astrophysics, University of La Laguna, E-38200 La Laguna, Tenerife, Canary Islands, Spain, Dipartimento di Fisica e Astronomia ‘Galileo Galilei’, Università degli Studi di Padova, Vicolo dell’Osservatorio 3, I-35122 Padova, Italy
2. Instituto de Astrofìsica de Canarias, Vìa Làctea S/N, E-38200 La Laguna, Tenerife, Spain, Department of Astrophysics, University of La Laguna, E-38200 La Laguna, Tenerife, Canary Islands, Spain
3. Instituto de Astrofìsica de Canarias, Vìa Làctea S/N, E-38200 La Laguna, Tenerife, Spain, INAF – Osservatorio Astronomico d’Abruzzo, Via M. Maggini, I-64100 Teramo, Italy, INFN - Sezione di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
4. Dipartimento di Fisica e Astronomia ‘Galileo Galilei’, Università degli Studi di Padova, Vicolo dell’Osservatorio 3, I-35122 Padova, Italy, INAF – Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova, Italy
5. National Optical Astronomy Observatory, P.O. Box 26732, Tucson, AZ 85719, USA
6. Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena, Chile

ABSTRACT We present the star formation history (SFH) of the Sculptor dwarf spheroidal galaxy based on deep g, r photometry taken with Dark Energy Camera at the Blanco telescope, focusing our analysis on the central region of the galaxy extended up to ∼3 core radii. We have investigated how the SFH changes radially, subdividing the sampled area into four regions, and have detected a clear trend of star formation. All the SFHs show a single episode of star formation, with the innermost region presenting a longer period of star formation of ∼1.5 Gyr and for the outermost region the main period of star formation is confined to ∼0.5 Gyr. We observe a gradient in the mean age which is found to increase going towards the outer regions. These results suggest that Sculptor continued forming stars after the reionization epoch in its central part, while in the peripheral region, the majority of stars probably formed during the reionization epoch and soon after its end. From our analysis, Sculptor cannot be considered strictly as a fossil of the reionization epoch.

• Sponsoring Organization: USDOE
• OSTI ID: 1531037
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 4 Vol. 487; ISSN 0035-8711
• Publisher: Oxford University PressCopyright Statement
• Country of Publication: United Kingdom
• Language: English