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Show THE UNIVERSITY OF UTAH RESEARCH POSTERS ON THE HILL 2013 CHEMICAL COMPOSITIONS IN THE YOUNG OUTER HALO CLUSTER NGC1261 Dan M. Filler (I. I. Ivans, J. Simmerer) Department of Physics and Astronomy University of Utah High Resolution Spectroscopy of N G C 1261 Dan Filler, Inese Ivans Department of Physics and Astronomy u T H E UNIVPRSITY OF U T AH ^™^ • » - - Globular chafers a n dense stellar iroiaw that contain 10.000 - 10.000.000 Stan. Shown above is a Hubble image of N G C 1261. 1 study the chemical abundances of Individual Stan by analyzing the spectnm (shown above) to learn about the evolution of 0.5 | o 0 •0.5 LTE NA-0 »-*:: ''•.'.'.iK-r • •.•• ,"•"" -;•• - ' - , - ' " - ; - • ; « • -1 -0.5 0 0.5 Oxygen (rom ,\tjf t. .K-lif iluiKn ryfn- !.'•:' . I . I Field Star Compar We present the first high-resolution (R~40,000) chemical abundance analysis of the relatively young (8-9 Gyr), outer halo Galactic globular cluster N G C 1261. Stellar parameters for three stars were derived using spectroscopic constraints. Abundances were deduced using a combination of EWs and fitting synthetic spectra. Our derived metallicity ([Fe/H] = -1.19 ± 0.02) is in excellent agreement with the metallicity scale of Kraft & Ivans (2003,2004). However, the Na-0 anticorrelation spanning 1.1 ± 0.1 dex in sodium, is as large as any other cluster reported to date. In the light element group, w e report -0.9 < [C/Fe] < -0.6 with CI 2/C13=4, (for which three regions in the G-band were synthesized); +0.5 < [N/Fe] < +1.1 from the CN band head near 8004A; -0.25 < [O/Fe] < +0.2 from the forbidden lines; -0.3 < [Al/Fe] < +0.15 from the aluminum doublet near 6696A. W e also present abundances for the alpha-elements [Mg/Fe] = +0.2 ± 0.1; [Si/Fe] = +0.1 ± 0.1; [Ca/Fe] = +0.15 ± 0.1; [Ti/Fe] = +0.15 ±0.15. N G C 1261 is distinguished from other clusters of comparable metallicity due to low-alpha abundances. W e will discuss the nucleosynthetic histories that may have given rise to these abundances including the possibility of enrichment by Type 1 a supernovae. W e also report abundances for the iron-peak elements [Sc/Fe] = +0.0 ± 0.2; [V/Fe] = -0.1 ± 0.1; [Cr/Fe] = -0.1 ± 0.15; [Mn/Fe] = -0.1 ± 0.15; [Co/Fe] = +0.2 ± 0.1; [Ni/Fe] = +0.0 ± 0.1; the light neutron-capture elements [Y/Fe] = +0.1 ± 0.1; [Zr/Fe] = +0.35 ± 0.1; the s-process elements [Ba/Fe] = +0.15 ±0.1; [La/Fe] = +0.1 ± 0.1; [Nd/Fe] = +0.15 ± 0.1; and the r-process element [Eu/Fe] = 0.6 ± 0.2. |05 & p KjiL °^=^~ •*: i 5 ^i^^^c"l^^^Ji^u^^^i^c^^A ^"tuJ^ o7»3^ |