GHOST Commissioning Science Results: Identifying a new chemically peculiar star in Reticulum II
Abstract
The Gemini High-resolution Optical SpecTrograph (GHOST) is the newest high resolution spectrograph to be developed for a large aperture telescope, recently deployed and commissioned at the Gemini-South telescope. In this paper, we present the first science results from the GHOST spectrograph taking during its commissioning runs. We have observed the bright metal-poor benchmark star HD 122563, along with two stars in the ultra faint dwarf galaxy, Ret II, one of which was previously identified as a candidate member, but did not have a previous detailed chemical abundance analysis. This star (GDR3 0928) is found to be a bona fide member of Ret II, and from a spectral synthesis analysis, it is also revealed to be a CEMP-r star, with significant enhancements in the several light elements (C, N, O, Na, Mg, and Si), in addition to featuring an r-process enhancement like many other Ret II stars. The light-element enhancements in this star resemble the abundance patterns seen in the CEMP-no stars of other ultra faint dwarf galaxies, and are thought to have been produced by an independent source from the r-process. These unusual abundance patterns are thought to be produced by faint supernovae, which may be produced by some of the earliest generations of stars.
Keywords
Cite
@article{arxiv.2306.04804,
title = {GHOST Commissioning Science Results: Identifying a new chemically peculiar star in Reticulum II},
author = {Christian R. Hayes and Kim A. Venn and Fletcher Waller and Jaclyn Jensen and Alan W. McConnachie and John Pazder and Federico Sestito and Andre Anthony and Gabriella Baker and John Bassett and Joao Bento and Gregory Burley and Jurek Brzeski and Scott Case and Edward Chapin and Timothy Chin and Eric Chisholm and Vladimir Churilov and Adam Densmore and Ruben Diaz and Jennifer Dunn and Michael Edgar and Tony Farrell and Veronica Firpo and Joeleff Fitzsimmons and Juan Font-Serra and Javier Fuentes and Colin Ganton and Manuel Gomez-Jimenez and Tim Hardy and David Henderson and Alexis Hill and Brian Hoff and Michael Ireland and Venu Kalari and Neal Kelly and Urs Klauser and Yuriy Kondrat and Kathleen Labrie and Sam Lambert and Lance Luvaul and Jon Lawrence and Jordan Lothrop and G. Scott Macdonald and Slavko Mali and Steve Margheim and Richard McDermid and Helen McGregor and Bryan Miller and Felipe Miranda and Rolf Muller and Jon Nielsen and Ryan Norbury and Oliver Oberdorf and Naveen Pai and Gabriel Perez and Pablo Prado and Ian Price and Carlos Quiroz and Vladimir Reshetov and Gordon Robertson and Roque Ruiz-Carmona and Ricardo Salinas and Kim M. Sebo and Andrew Sheinis and Matthew Shetrone and Keith Shortridge and Katherine Silversides and Karleyne Silva and Chris Simpson and Greg Smith and Kei Szeto and Julia Tims and Eduardo Toro and Cristian Urrutia and Sudharshan Venkatesan and Lewis Waller and Ivan Wevers and Ramunas Wierzbicki and Marc White and Peter Young and Ross Zhelem},
journal= {arXiv preprint arXiv:2306.04804},
year = {2023}
}
Comments
23 pages, 9 figures, 7 tables, submitted to the AAS Journals