Browsing by Author "Jackson, Kelly M."
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Item New Red Jewels in Coma Berenices(IOP Publishing Ltd, 2014-01-28) Terrien, Ryan C.; Mahadevan, Suvrath; Deshpande, Rohit; Bender, Chad F.; Cargile, Phillip A.; Hearty, Frederick R.; Cottaar, Michiel; Jackson, Kelly M.We have used Sloan Digital Sky Survey-III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) radial velocity observations in the near-infrared H-band to explore the membership of the nearby (86.7 ± 0.9 pc) open cluster Coma Berenices (Melotte 111), concentrating on the poorly populated low-mass end of the main sequence. Using SDSS-III APOGEE radial velocity measurements, we confirm the membership of eight K/M dwarf members, providing the first confirmed low-mass members of the Coma Berenices cluster. Using R similar to 2000 spectra from IRTF-SpeX, we confirm the independently luminosity classes of these targets, and find their metallicities to be consistent with the known solar mean metallicity of Coma Berenices and of M dwarfs in the solar neighborhood. In addition, the APOGEE spectra have enabled measurement of v sin i for each target and detection for the first time of the low-mass secondary components of the known binary systems Melotte 111 102 and Melotte 111 120, as well as identification of the previously unknown binary system 2MASS J12214070+2707510. Finally, we use Kilodegree Extremely Little Telescope photometry to measure photometric variability and rotation periods for a subset of the Coma Berenices members.Item The Open Cluster Chemical Analysis and Mapping Survey: Local Galactic Metallicity Gradient with Apogee Using SDSS-III DR10(2013-10-09) Frinchaboy, P. M.; Thompson, B.; Jackson, Kelly M.; O'Connell, J.; Meyer, B.; Zasowski, G.; Majewski, S. R.The Open Cluster Chemical Analysis and Mapping (OCCAM) survey aims to produce a comprehensive, uniform, infrared-based data set for hundreds of open clusters, and constrain key Galactic dynamical and chemical parameters from this sample. This first contribution from the OCCAM survey presents analysis of 141 members stars in 28 open clusters with high-resolution metallicities derived from a large uniform sample collected as part of the Sloan Digital Sky Survey III/Apache Point Observatory Galactic Evolution Experiment. This sample includes the first high-resolution metallicity measurements for 22 open clusters. With this largest ever uniformly observed sample of open cluster stars we investigate the Galactic disk gradients of both [M/H] and [α/M]. We find basically no gradient in [α/M] across 7.9 kpc ≤ R GC ≤ 14.5 kpc, but [M/H] does show a gradient for R GC < 10 kpc and a significant flattening beyond R GC = 10 kpc. In particular, whereas fitting a single linear trend yields an [M/H] gradient of -0.09 ± 0.03 dex kpc -1 - similar to previously measure gradients inside 13 kpc - by independently fitting inside and outside 10 kpc separately we find a significantly steeper gradient near the Sun (7.9 ≤ R GC ≤ 10) than previously found (-0.20 ± 0.08 dex kpc-1) and a nearly flat trend beyond 10 kpc (-0.02 ± 0.09 dex kpc-1).Item The Tenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SSDD-III Apache Point Observatory Galactic Evolution Experiment(IOP Publishing Ltd, 2014-03-18) Ahn, Christopher P.; Alexandroff, Rachael; Allende Prieto, Carlos; Anders, Friedrich; Anderson, Scott F.; Anderton, Timothy; Andrews, Brett H.; Jackson, Kelly M.The Sloan Digital Sky Survey (SDSS) has been in operation since 2000 April. This paper presents the Tenth Public Data Release (DR10) from its current incarnation, SDSS-III. This data release includes the first spectroscopic data from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS) taken through 2012 July. The APOGEE instrument is a near-infrared R ~ 22,500 300 fiber spectrograph covering 1.514-1.696 μm. The APOGEE survey is studying the chemical abundances and radial velocities of roughly 100,000 red giant star candidates in the bulge, bar, disk, and halo of the Milky Way. DR10 includes 178,397 spectra of 57,454 stars, each typically observed three or more times, from APOGEE. Derived quantities from these spectra (radial velocities, effective temperatures, surface gravities, and metallicities) are also included. DR10 also roughly doubles the number of BOSS spectra over those included in the Ninth Data Release. DR10 includes a total of 1,507,954 BOSS spectra comprising 927,844 galaxy spectra, 182,009 quasar spectra, and 159,327 stellar spectra selected over 6373.2 deg(-2).