학술논문
GHOST Commissioning Science Results: Identifying a new chemically peculiar star in Reticulum II
Document Type
Working Paper
Author
Hayes, Christian R.; Venn, Kim A.; Waller, Fletcher; Jensen, Jaclyn; McConnachie, Alan W.; Pazder, John; Sestito, Federico; Anthony, Andre; Baker, Gabriella; Bassett, John; Bento, Joao; Burley, Gregory; Brzeski, Jurek; Case, Scott; Chapin, Edward; Chin, Timothy; Chisholm, Eric; Churilov, Vladimir; Densmore, Adam; Diaz, Ruben; Dunn, Jennifer; Edgar, Michael; Farrell, Tony; Firpo, Veronica; Fitzsimmons, Joeleff; Font-Serra, Juan; Fuentes, Javier; Ganton, Colin; Gomez-Jimenez, Manuel; Hardy, Tim; Henderson, David; Hill, Alexis; Hoff, Brian; Ireland, Michael; Kalari, Venu; Kelly, Neal; Klauser, Urs; Kondrat, Yuriy; Labrie, Kathleen; Lambert, Sam; Luvaul, Lance; Lawrence, Jon; Lothrop, Jordan; Macdonald, G. Scott; Mali, Slavko; Margheim, Steve; McDermid, Richard; McGregor, Helen; Miller, Bryan; Miranda, Felipe; Muller, Rolf; Nielsen, Jon; Norbury, Ryan; Oberdorf, Oliver; Pai, Naveen; Perez, Gabriel; Prado, Pablo; Price, Ian; Quiroz, Carlos; Reshetov, Vladimir; Robertson, Gordon; Ruiz-Carmona, Roque; Salinas, Ricardo; Sebo, Kim M.; Sheinis, Andrew; Shetrone, Matthew; Shortridge, Keith; Silversides, Katherine; Silva, Karleyne; Simpson, Chris; Smith, Greg; Szeto, Kei; Tims, Julia; Toro, Eduardo; Urrutia, Cristian; Venkatesan, Sudharshan; Waller, Lewis; Wevers, Ivan; Wierzbicki, Ramunas; White, Marc; Young, Peter; Zhelem, Ross
Source
Subject
Language
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.
Comment: 23 pages, 9 figures, 7 tables, submitted to the AAS Journals
Comment: 23 pages, 9 figures, 7 tables, submitted to the AAS Journals