Published January 20, 2022 | Version Accepted Version + Published
Journal Article Open

Simultaneous Constraints on the Star Formation History and Nucleosynthesis of Sculptor dSph

  • 1. ROR icon California Institute of Technology
  • 2. ROR icon University of Notre Dame
  • 3. ROR icon Carnegie Observatories
  • 4. ROR icon University of Chicago

Abstract

We demonstrate that using up to seven stellar abundance ratios can place observational constraints on the star formation histories (SFHs) of Local Group dSphs, using Sculptor dSph as a test case. We use a one-zone chemical evolution model to fit the overall abundance patterns of α elements (which probe the core-collapse supernovae that occur shortly after star formation), s-process elements (which probe AGB nucleosynthesis at intermediate delay times), and iron-peak elements (which probe delayed Type Ia supernovae). Our best-fit model indicates that Sculptor dSph has an ancient SFH, consistent with previous estimates from deep photometry. However, we derive a total star formation duration of ∼0.9 Gyr, which is shorter than photometrically derived SFHs. We explore the effect of various model assumptions on our measurement and find that modifications to these assumptions still produce relatively short SFHs of duration ≲1.4 Gyr. Our model is also able to compare sets of predicted nucleosynthetic yields for supernovae and AGB stars, and can provide insight into the nucleosynthesis of individual elements in Sculptor dSph. We find that observed [Mn/Fe] and [Ni/Fe] trends are most consistent with sub-MCh Type Ia supernova models, and that a combination of "prompt" (delay times similar to core-collapse supernovae) and "delayed" (minimum delay times ≳50 Myr) r-process events may be required to reproduce observed [Ba/Mg] and [Eu/Mg] trends.

Additional Information

© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 August 2; revised 2021 September 23; accepted 2021 October 24; published 2022 January 26. This material is based upon work supported by the National Science Foundation under grant No. AST-1847909. M.A.d.l.R. and E.H.N. acknowledge the financial support of the NSF Graduate Research Fellowship Program. E.N.K. gratefully acknowledges support from a Cottrell Scholar award administered by the Research Corporation for Science Advancement. A.P.J. acknowledges support from a Carnegie Fellowship and the Thacher Research Award in Astronomy. There are many communities without whom this work would not have been possible. We thank the anonymous reviewer for comments that helped improve the paper. We acknowledge that this work is rooted in Western scientific practices and is the material product of a long and complex history of settler-colonialism. M.A.d.l.R., E.N.K., E.H.N., and A.P.J. wish to recognize their status as settlers on the traditional and unceded territory of the Tongva peoples, and to recognize that the astronomical observations described in this paper were only possible because of the dispossession of Maunakea from ${\rm{K}}\bar{{\rm{a}}}$naka Maoli. We hope to work toward a scientific practice guided by pono and a future in which we all honor the land. Finally, we would like to express our deep gratitude to the staff at academic and telescope facilities, particularly those whose communities are excluded from the academic system but whose labor maintains spaces for scientific inquiry. Facility: Keck:II (DEIMOS). - Software: Matplotlib (Hunter 2007), Astropy (Robitaille et al. 2013), Scipy (Jones et al. 2001), emcee (Foreman-Mackey et al. 2013).

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Published - de_los_Reyes_2022_ApJ_925_66.pdf

Accepted Version - 2110.01690.pdf

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Additional details

Identifiers

Eprint ID
112103
Resolver ID
CaltechAUTHORS:20211130-215710052

Related works

Funding

NSF
AST-1847909
NSF Graduate Research Fellowship
Cottrell Scholar of Research Corporation
Carnegie Institution of Washington
Carnegie Observatories

Dates

Created
2021-12-02
Created from EPrint's datestamp field
Updated
2022-01-28
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Caltech Custom Metadata

Caltech groups
Astronomy Department