ON THE METALLICITY DISTRIBUTION OF THE PECULIAR GLOBULAR CLUSTER M22

Journal Article · Sat Oct 01 04:00:00 EDT 2016 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.3847/0067-0049/226/2/16· OSTI ID:22661038

Lee, Jae-Woo ^[1]

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1. Department of Physics and Astronomy, Sejong University, 209 Neungdong-ro, Gwangjin-Gu, Seoul, 05006 (Korea, Republic of)

In our previous study, we showed that the peculiar globular cluster (GC) M22 contains two distinct stellar populations, namely the Ca - w and Ca - s groups, which have different physical properties, chemical compositions, spatial distributions, and kinematics. We proposed that M22 was most likely formed via a merger of two GCs with heterogeneous metallicities in a dwarf galaxy environment and then later accreted to our Galaxy. In their recent study, Mucciarelli et al. claimed that M22 is a normal monometallic globular cluster without any perceptible metallicity spread among the two groups of stars, which challenges our results and those of others. We devise new strategies for the local thermodynamic equilibrium abundance analysis of red giant branch stars in GCs and show that there exists a spread in the iron abundance distribution in M22.

• OSTI ID: 22661038
• Journal Information: Astrophysical Journal, Supplement Series, Journal Name: Astrophysical Journal, Supplement Series Journal Issue: 2 Vol. 226; ISSN 0067-0049; ISSN APJSA2
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CALCIUM
CHEMICAL COMPOSITION
ELEMENT ABUNDANCE
GALAXY CLUSTERS
IRON
LTE
METALLICITY
MILKY WAY
PHYSICAL PROPERTIES
SPATIAL DISTRIBUTION
STAR CLUSTERS
STAR EVOLUTION
STARS
THERMODYNAMICS