Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/6650
Title: Discovery of Relatively Hydrogen-poor Giants in the Galactic Globular Cluster omega Centauri
Authors: Hema, B. P
Pandey, G
Keywords: Globular clusters: general;Globular clusters: individual (Omega Centauri);Stars: chemically peculiar
Issue Date: 10-Sep-2014
Publisher: IOP Publishing
Citation: The Astrophysical Journal Letters, Vol. 792, No. 2, L28
Abstract: In this Letter, the results of our low-resolution spectroscopic survey for identifying hydrogen-deficient stars in the red giant sample of the globular cluster ω Cen are reported. Spectral analyses were carried out on the basis of the strengths of the (0, 0) MgH band and the Mg b triplet. In our sample, four giants were identified with weak/absent MgH bands in their observed spectra, which was unexpected for their well determined stellar parameters. The Mg abundances for the program stars were determined from the subordinate lines of the MgH band to the blue of the Mg b triplet, using the spectral synthesis technique. The derived Mg abundances for the program stars were as expected for the red giants of ω Cen, except for the four identified candidates. The determined Mg abundances of these four candidates are much lower than that expected for the red giants of ω Cen, and are unacceptable based on the strengths of the Mg b triplet in their observed spectra. Hence, a plausible explanation for the weak/absent MgH bands in the observed spectra of these stars is a relatively lower abundance of hydrogen in their atmospheres. These giants may belong to the group of helium-enriched red giants of ω Cen.
Description: Open Access
URI: http://hdl.handle.net/2248/6650
ISSN: 2041-8205
???metadata.dc.rights???: © IOP Publishing
???metadata.dc.relation.uri???: http://dx.doi.org/10.1088/2041-8205/792/2/L28
Appears in Collections:IIAP Publications

Files in This Item:
File Description SizeFormat 
Discovery of Relatively Hydrogen-poor Giants in the Galactic Globular Cluster omega Centauri.pdfOpen Access467.55 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.