A spectroscopic binary in the Hercules dwarf spheroidal galaxy

Physics

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https://doi.org/10.1088/0004-637X/780/1/91
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A spectroscopic binary in the Hercules dwarf spheroidal galaxy. / Koch, Andreas; Hansen, Terese; Feltzing, S. et al.
In: The Astrophysical Journal, Vol. 780, No. 1, 91, 13.12.2013.

Research output: Contribution to Journal/Magazine › Journal article › peer-review

Harvard

Koch, A, Hansen, T, Feltzing, S & Wilkinson, MI 2013, 'A spectroscopic binary in the Hercules dwarf spheroidal galaxy', The Astrophysical Journal, vol. 780, no. 1, 91. https://doi.org/10.1088/0004-637X/780/1/91

APA

Koch, A., Hansen, T., Feltzing, S., & Wilkinson, M. I. (2013). A spectroscopic binary in the Hercules dwarf spheroidal galaxy. The Astrophysical Journal, 780(1), Article 91. https://doi.org/10.1088/0004-637X/780/1/91

Vancouver

Koch A, Hansen T, Feltzing S, Wilkinson MI. A spectroscopic binary in the Hercules dwarf spheroidal galaxy. The Astrophysical Journal. 2013 Dec 13;780(1):91. doi: 10.1088/0004-637X/780/1/91

Author

Koch, Andreas ; Hansen, Terese ; Feltzing, S. et al. / A spectroscopic binary in the Hercules dwarf spheroidal galaxy. In: The Astrophysical Journal. 2013 ; Vol. 780, No. 1.

Bibtex

@article{6ba95bd4b5c9492e9f31ee6e6cf5dbff,

title = "A spectroscopic binary in the Hercules dwarf spheroidal galaxy",

abstract = "We present the radial velocity curve of a single-lined spectroscopic binary in the faint Hercules dwarf spheroidal (dSph) galaxy, based on 34 individual spectra covering more than 2 yr of observations. This is the first time that orbital elements could be derived for a binary in a dSph. The system consists of a metal-poor red giant and a low-mass companion, possibly a white dwarf, with a 135 day period in a moderately eccentric (e = 0.18) orbit. Its period and eccentricity are fully consistent with metal-poor binaries in the Galactic halo, while the projected semimajor axis is small, at ap sin i = 38 R ☉. In fact, a very close orbit could inhibit the production of heavier elements through s-process nucleosynthesis, leading to the very low abundances of neutron-capture elements that are found in this star. We discuss the further implications for the chemical enrichment history of the Hercules dSph, but find no compelling binary scenario that could reasonably explain the full, peculiar abundance pattern of the Hercules dSph galaxy.",

author = "Andreas Koch and Terese Hansen and S. Feltzing and Wilkinson, {Mark I.}",

year = "2013",

month = dec,

day = "13",

doi = "10.1088/0004-637X/780/1/91",

language = "English",

volume = "780",

journal = "The Astrophysical Journal",

issn = "0004-637X",

publisher = "Institute of Physics Publishing",

number = "1",

}

RIS

TY - JOUR

T1 - A spectroscopic binary in the Hercules dwarf spheroidal galaxy

AU - Koch, Andreas

AU - Hansen, Terese

AU - Feltzing, S.

AU - Wilkinson, Mark I.

PY - 2013/12/13

Y1 - 2013/12/13

N2 - We present the radial velocity curve of a single-lined spectroscopic binary in the faint Hercules dwarf spheroidal (dSph) galaxy, based on 34 individual spectra covering more than 2 yr of observations. This is the first time that orbital elements could be derived for a binary in a dSph. The system consists of a metal-poor red giant and a low-mass companion, possibly a white dwarf, with a 135 day period in a moderately eccentric (e = 0.18) orbit. Its period and eccentricity are fully consistent with metal-poor binaries in the Galactic halo, while the projected semimajor axis is small, at ap sin i = 38 R ☉. In fact, a very close orbit could inhibit the production of heavier elements through s-process nucleosynthesis, leading to the very low abundances of neutron-capture elements that are found in this star. We discuss the further implications for the chemical enrichment history of the Hercules dSph, but find no compelling binary scenario that could reasonably explain the full, peculiar abundance pattern of the Hercules dSph galaxy.

AB - We present the radial velocity curve of a single-lined spectroscopic binary in the faint Hercules dwarf spheroidal (dSph) galaxy, based on 34 individual spectra covering more than 2 yr of observations. This is the first time that orbital elements could be derived for a binary in a dSph. The system consists of a metal-poor red giant and a low-mass companion, possibly a white dwarf, with a 135 day period in a moderately eccentric (e = 0.18) orbit. Its period and eccentricity are fully consistent with metal-poor binaries in the Galactic halo, while the projected semimajor axis is small, at ap sin i = 38 R ☉. In fact, a very close orbit could inhibit the production of heavier elements through s-process nucleosynthesis, leading to the very low abundances of neutron-capture elements that are found in this star. We discuss the further implications for the chemical enrichment history of the Hercules dSph, but find no compelling binary scenario that could reasonably explain the full, peculiar abundance pattern of the Hercules dSph galaxy.

U2 - 10.1088/0004-637X/780/1/91

DO - 10.1088/0004-637X/780/1/91

M3 - Journal article

VL - 780

JO - The Astrophysical Journal

JF - The Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 91

ER -

Research

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