S5: The Destruction of a Bright Dwarf Galaxy as Revealed by the Chemistry of the Indus Stellar Stream

S5 Collaboration

doi:10.3847/1538-4357/abfc54

S⁵: The Destruction of a Bright Dwarf Galaxy as Revealed by the Chemistry of the Indus Stellar Stream

S5 Collaboration

School of Physics and Astronomy

Research output: Contribution to journal › Article › Research › peer-review

12 Citations (Scopus)

Abstract

The recently discovered Indus stellar stream exhibits a diverse chemical signature compared to what is found for most other streams due to the abundances of two outlier stars, Indus_0 and Indus_13. Indus_13 exhibits an extreme enhancement in rapid neutron-capture (r-)process elements with [Eu/Fe] = + 1.81. It thus provides direct evidence of the accreted nature of r-process-enhanced stars. In this paper we present a detailed chemical analysis of the neutron-capture elements in Indus_13, revealing the star to be slightly actinide poor. The other outlier, Indus_0, displays a globular cluster-like signature with high N, Na, and Al abundances, while the rest of the Indus stars show abundances compatible with a dwarf galaxy origin. Hence, Indus_0 provides the first chemical evidence of a fully disrupted dwarf containing a globular cluster. We use the chemical signature of the Indus stars to discuss the nature of the stream progenitor which was likely a chemically evolved system, with a mass somewhere in the range from Ursa Minor to Fornax.

Original language	English
Article number	103
Number of pages	11
Journal	The Astrophysical Journal
Volume	915
Issue number	2
DOIs	https://doi.org/10.3847/1538-4357/abfc54
Publication status	Published - 10 Jul 2021

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10.3847/1538-4357/abfc54Licence: CC BY

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@article{ab97a26158ba483eb3f5a5a0fc5a15e2,

title = "S5: The Destruction of a Bright Dwarf Galaxy as Revealed by the Chemistry of the Indus Stellar Stream",

abstract = "The recently discovered Indus stellar stream exhibits a diverse chemical signature compared to what is found for most other streams due to the abundances of two outlier stars, Indus_0 and Indus_13. Indus_13 exhibits an extreme enhancement in rapid neutron-capture (r-)process elements with [Eu/Fe] = + 1.81. It thus provides direct evidence of the accreted nature of r-process-enhanced stars. In this paper we present a detailed chemical analysis of the neutron-capture elements in Indus_13, revealing the star to be slightly actinide poor. The other outlier, Indus_0, displays a globular cluster-like signature with high N, Na, and Al abundances, while the rest of the Indus stars show abundances compatible with a dwarf galaxy origin. Hence, Indus_0 provides the first chemical evidence of a fully disrupted dwarf containing a globular cluster. We use the chemical signature of the Indus stars to discuss the nature of the stream progenitor which was likely a chemically evolved system, with a mass somewhere in the range from Ursa Minor to Fornax. ",

author = "Hansen, {Terese T.} and Ji, {Alexander P.} and {Da Costa}, {Gary S.} and Li, {Ting S.} and Casey, {Andrew R.} and Pace, {Andrew B.} and Cullinane, {Lara R.} and Denis Erkal and Koposov, {Sergey E.} and Kyler Kuehn and Lewis, {Geraint F.} and Dougal Mackey and Simpson, {Jeffrey D.} and Nora Shipp and Zucker, {Daniel B.} and Joss Bland-Hawthorn and {S5 Collaboration}",

note = "Funding Information: T.T.H. acknowledges generous support from the George P. and Cynthia Woods Institute for Fundamental Physics and Astronomy at Texas A&M University. A.P.J. acknowledges support from a Carnegie Fellowship and the Thacher Research Award in Astronomy. A.B.P. is supported by NSF grant AST-1813881. T.S.L. is supported by NASA through Hubble Fellowship grant HST-HF2-51439.001 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. A.R.C. is supported in part by the Australian Research Council through a Discovery Early Career Researcher Award (DE190100656). Parts of this research were supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. Publisher Copyright: {\textcopyright} 2021. The American Astronomical Society. All rights reserved.. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.",

year = "2021",

month = jul,

day = "10",

doi = "10.3847/1538-4357/abfc54",

language = "English",

volume = "915",

journal = "The Astrophysical Journal",

issn = "1538-4357",

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T2 - The Destruction of a Bright Dwarf Galaxy as Revealed by the Chemistry of the Indus Stellar Stream

AU - Hansen, Terese T.

AU - Ji, Alexander P.

AU - Da Costa, Gary S.

AU - Li, Ting S.

AU - Casey, Andrew R.

AU - Pace, Andrew B.

AU - Cullinane, Lara R.

AU - Erkal, Denis

AU - Koposov, Sergey E.

AU - Kuehn, Kyler

AU - Lewis, Geraint F.

AU - Mackey, Dougal

AU - Simpson, Jeffrey D.

AU - Shipp, Nora

AU - Zucker, Daniel B.

AU - Bland-Hawthorn, Joss

AU - S5 Collaboration

N1 - Funding Information: T.T.H. acknowledges generous support from the George P. and Cynthia Woods Institute for Fundamental Physics and Astronomy at Texas A&M University. A.P.J. acknowledges support from a Carnegie Fellowship and the Thacher Research Award in Astronomy. A.B.P. is supported by NSF grant AST-1813881. T.S.L. is supported by NASA through Hubble Fellowship grant HST-HF2-51439.001 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. A.R.C. is supported in part by the Australian Research Council through a Discovery Early Career Researcher Award (DE190100656). Parts of this research were supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. Publisher Copyright: © 2021. The American Astronomical Society. All rights reserved.. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/7/10

Y1 - 2021/7/10

N2 - The recently discovered Indus stellar stream exhibits a diverse chemical signature compared to what is found for most other streams due to the abundances of two outlier stars, Indus_0 and Indus_13. Indus_13 exhibits an extreme enhancement in rapid neutron-capture (r-)process elements with [Eu/Fe] = + 1.81. It thus provides direct evidence of the accreted nature of r-process-enhanced stars. In this paper we present a detailed chemical analysis of the neutron-capture elements in Indus_13, revealing the star to be slightly actinide poor. The other outlier, Indus_0, displays a globular cluster-like signature with high N, Na, and Al abundances, while the rest of the Indus stars show abundances compatible with a dwarf galaxy origin. Hence, Indus_0 provides the first chemical evidence of a fully disrupted dwarf containing a globular cluster. We use the chemical signature of the Indus stars to discuss the nature of the stream progenitor which was likely a chemically evolved system, with a mass somewhere in the range from Ursa Minor to Fornax.

AB - The recently discovered Indus stellar stream exhibits a diverse chemical signature compared to what is found for most other streams due to the abundances of two outlier stars, Indus_0 and Indus_13. Indus_13 exhibits an extreme enhancement in rapid neutron-capture (r-)process elements with [Eu/Fe] = + 1.81. It thus provides direct evidence of the accreted nature of r-process-enhanced stars. In this paper we present a detailed chemical analysis of the neutron-capture elements in Indus_13, revealing the star to be slightly actinide poor. The other outlier, Indus_0, displays a globular cluster-like signature with high N, Na, and Al abundances, while the rest of the Indus stars show abundances compatible with a dwarf galaxy origin. Hence, Indus_0 provides the first chemical evidence of a fully disrupted dwarf containing a globular cluster. We use the chemical signature of the Indus stars to discuss the nature of the stream progenitor which was likely a chemically evolved system, with a mass somewhere in the range from Ursa Minor to Fornax.

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DO - 10.3847/1538-4357/abfc54

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SN - 1538-4357

VL - 915

JO - The Astrophysical Journal

JF - The Astrophysical Journal

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M1 - 103

ER -

S⁵: The Destruction of a Bright Dwarf Galaxy as Revealed by the Chemistry of the Indus Stellar Stream

Abstract

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The stars that should not exist

ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions

Cite this

S5: The Destruction of a Bright Dwarf Galaxy as Revealed by the Chemistry of the Indus Stellar Stream

Abstract

Access to Document

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Projects

The stars that should not exist

ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions

Cite this

S⁵: The Destruction of a Bright Dwarf Galaxy as Revealed by the Chemistry of the Indus Stellar Stream