Abundance analysis of a nitrogen-rich extreme-helium hot subdwarf from the SALT survey

Scott LJA, Jeffery CS, Farren D, Tap C, Dorsch M (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Monthly Notices of the Royal Astronomical Society Oxford University Press

Book Volume: 521

Pages Range: 3431-3440

Journal Issue: 3

DOI: 10.1093/mnras/stad688

Abstract

We have performed a detailed spectral analysis of the helium-rich hot subdwarf EC 20187 -4939, using data obtained in the SALT surv e y of helium-rich hot subdwarfs. We have measured its ef fecti ve temperature, surface gravity, and chemical abundances from the spectrum. Its radius has also been determined by fitting the spectral energy distribution using photometric data, from which a mass of 0.44 (+ 0 . 32) (-0 . 19) M-? has been inferred using the measurement of surface gravity. This star is particularly abundant in helium and nitrogen, whilst being both carbon and oxygen-weak. The surface abundances and mass have been found to be consistent with a helium white dwarf merger product. The abundance effects of alpha captures on nitrogen during the merger process and possible connections between EC 20187 -4939, and other carbon-weak related objects are discussed.

Involved external institutions

Armagh Observatory GB United Kingdom (GB) Trinity College Dublin IE Ireland (IE) Universität Potsdam DE Germany (DE)

How to cite

APA:

Scott, L.J.A., Jeffery, C.S., Farren, D., Tap, C., & Dorsch, M. (2023). Abundance analysis of a nitrogen-rich extreme-helium hot subdwarf from the SALT survey. Monthly Notices of the Royal Astronomical Society, 521(3), 3431-3440. https://doi.org/10.1093/mnras/stad688

MLA:

Scott, L. J. A., et al. "Abundance analysis of a nitrogen-rich extreme-helium hot subdwarf from the SALT survey." Monthly Notices of the Royal Astronomical Society 521.3 (2023): 3431-3440.

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