A SURVEY OF CN AND CH VARIATIONS IN GALACTIC GLOBULAR CLUSTERS FROM SLOAN DIGITAL SKY SURVEY SPECTROSCOPY

Journal Article · Sat Oct 15 04:00:00 EDT 2011 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/142/4/126· OSTI ID:21582825

Smolinski, Jason P; Beers, Timothy C; Lee, Young Sun ^[1]

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1. Department of Physics and Astronomy and JINA: Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48824 (United States)

We present a homogeneous survey of the CN and CH band strengths in eight Galactic globular clusters observed during the course of the Sloan Extension for Galactic Understanding and Exploration sub-survey of the Sloan Digital Sky Survey. We confirm the existence of a bimodal CN distribution among red giant branch (RGB) stars in all of the clusters with metallicity greater than [Fe/H] = -1.7; the lowest metallicity cluster with an observed CN bimodality is M53, with [Fe/H] {approx_equal} -2.1. There is also some evidence for individual CN groups on the subgiant branches of M92, M2, and M13, and on the RGBs of M92 and NGC 5053. Finally, we quantify the correlation between overall cluster metallicity and the slope of the CN band strength-luminosity plot as a means of further demonstrating the level of CN enrichment in cluster giants. Our results agree well with previous studies reported in the literature.

• OSTI ID: 21582825
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 4 Vol. 142; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
EVOLUTION
LUMINOSITY
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SPECTROSCOPY
STAR CLUSTERS
STAR EVOLUTION
STARS