Publications (113)
Mg isotopic ratios in giant stars of the globular cluster NGC 6752
David Yong, Frank Grundahl, David L. Lambert +2
Mg isotopic abundance ratios are measured in 20 bright red giants in globular cluster NGC 6752 based on very high-resolution, high signal-to-noise spectra obtained with UVES on the…
The origin of accreted stellar halo populations in the Milky Way using APOGEE, , and the EAGLE simulations
J. Ted Mackereth, Ricardo P. Schiavon, Joel Pfeffer +12
Recent work indicates that the nearby Galactic halo is dominated by the debris from a major accretion event. We confirm that result from an analysis of APOGEE-DR14 element abundanc…
APOGEE Chemical Abundances of the Sagittarius Dwarf Galaxy
Sten Hasselquist, Matthew Shetrone, Verne Smith +23
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) provides the opportunity to measure elemental abundances for C, N, O, Na, Mg, Al, Si, P, K, Ca, V, Cr, Mn, Fe, C…
The SDSS-III APOGEE Spectral Line List for H-band Spectroscopy
Matthew Shetrone, Dmitry Bizyaev, James Lawler +15
We present the -band spectral line lists adopted by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). The APOGEE line lists comprise astrophysical, theoretica…
The Correlation Between Mixing Length and Metallicity on the Giant Branch: Implications for Ages in the Gaia Era
Jamie Tayar, Garrett Somers, Marc H. Pinsonneault +28
In the updated APOGEE-Kepler catalog, we have asteroseismic and spectroscopic data for over 3000 first ascent red giants. Given the size and accuracy of this sample, these data off…
Homogeneous Analysis of Globular Clusters from the APOGEE Survey with the BACCHUS Code. II. The Southern Clusters and Overview
Szabolcs Mészáros, Thomas Masseron, D. A. GarcÃa-Hernández +33
We investigate the Fe, C, N, O, Mg, Al, Si, K, Ca, Ce and Nd abundances of 2283 red giant stars in 31 globular clusters from high-resolution spectra observed in both the northern a…
Final Targeting Strategy for the SDSS-IV APOGEE-2N Survey
Rachael L. Beaton, Ryan J. Oelkers, Christian R. Hayes +57
APOGEE-2 is a dual-hemisphere, near-infrared (NIR), spectroscopic survey with the goal of producing a chemo-dynamical mapping of the Milky Way Galaxy. The targeting for APOGEE-2 is…
Abundance Patterns in the Draco, Sextans and Ursa Minor Dwarf Spheroidal Galaxies
Matthew Shetrone, Patrick Cote, W. L. W. Sargent
The Keck I telescope has been used to obtain HIRES spectra for red giants belonging to the Draco, Sextans and Ursa Minor dwarf spheroidal (dSph) galaxies. An analysis of these spec…
The Extreme Ends of the Metallicity Distribution in dSph Galaxies
Matthew Shetrone
This paper reviews recent abundance results of local dSph giants. All dSph systems seem to show evidence of slow star formation rates, compared to the Milky Way, based on the most…
APOGEE Data Releases 13 and 14: Data and Analysis
Jon A. Holtzman, Sten Hasselquist, Matthew Shetrone +23
Data and analysis methodology used for the SDSS/APOGEE Data Releases 13 and 14 are described, highlighting differences from the DR12 analysis presented in Holtzman (2015). Some imp…
The S2 Stream: the shreds of a primitive dwarf galaxy
David S. Aguado, G. C. Myeong, Vasily Belokurov +12
The S2 stream is a kinematically cold stream that is plunging downwards through the Galactic disc. It may be part of a hotter and more diffuse structure called the Helmi stream. We…
GHOST Commissioning Science Results: Identifying a new chemically peculiar star in Reticulum II
Christian R. Hayes, Kim A. Venn, Fletcher Waller +79
The Gemini High-resolution Optical SpecTrograph (GHOST) is the newest high resolution spectrograph to be developed for a large aperture telescope, recently deployed and commissione…
The chemical characterisation of halo substructure in the Milky Way based on APOGEE
Danny Horta, Ricardo P. Schiavon, J. Ted Mackereth +21
Galactic haloes in a -CDM universe are predicted to host today a swarm of debris resulting from cannibalised dwarf galaxies. The chemo-dynamical information recorded in their s…
Identifying Sagittarius Stream Stars By Their APOGEE Chemical Abundance Signatures
Sten Hasselquist, Jeffrey L. Carlin, Jon A. Holtzman +17
The SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey provides precise chemical abundances of 18 chemical elements for 176,000 red giant stars d…
The Sixteenth Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra
Romina Ahumada, Carlos Allende Prieto, Andres Almeida +310
This paper documents the sixteenth data release (DR16) from the Sloan Digital Sky Surveys; the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of…
Chemical Evolution in the Milky Way: Rotation-based ages for APOGEE-Kepler cool dwarf stars
Zachary R. Claytor, Jennifer L. van Saders, Angela R. G. Santos +5
We use models of stellar angular momentum evolution to determine ages for stars in the APOGEE-\textit{Kepler} Cool Dwarfs sample. We focus on lower main-sequence stars, w…
Using the Multi-Object Adaptive Optics demonstrator RAVEN to observe metal-poor stars in and towards the Galactic Centre
Masen Lamb, Kim Venn, David Andersen +16
The chemical abundances for five metal-poor stars in and towards the Galactic bulge have been determined from H-band infrared spectroscopy taken with the RAVEN multi-object adaptiv…
High-resolution, H band Spectroscopy of Be Stars with SDSS-III/APOGEE: I. New Be Stars, Line Identifications, and Line Profiles
S. Drew Chojnowski, David G. Whelan, John P. Wisniewski +26
APOGEE has amassed the largest ever collection of multi-epoch, high-resolution (R~22,500), H-band spectra for B-type emission line (Be) stars. The 128/238 APOGEE Be stars for which…
An Investigation of Non-Canonical Mixing in Red Giant Stars Using APOGEE 12C/13C Ratios Observed in Open Cluster Stars
Caroline McCormick, Steven R. Majewski, Verne V. Smith +9
Standard stellar evolution theory poorly predicts the surface abundances of chemical species in low-mass, red giant branch (RGB) stars. Observations show an enhancement of p-p chai…
New Analyses of Star-to-Star Abundance Variations Among Bright Giants in the Mildly Metal-Poor Globular Cluster M5
Inese I. Ivans, Robert P. Kraft, Christopher Sneden +3
We present a chemical composition analysis of 36 giant stars in the mildly metal-poor globular cluster M5 (NGC 5904). The analysis makes use of high resolution data acquired at the…
NLTE for APOGEE: Simultaneous Multi-Element NLTE Radiative Transfer
Yeisson Osorio, Carlos Allende-Prieto, Ivan Hubeny +2
The new version of TLUSTY allows for the calculation of restricted NLTE in cool stars using pre-calculated opacity tables. We demonstrate that TLUSTY gives consistent results with…
The Origin of the 300 km s Stream Near Segue 1
Sal Wanying Fu, Joshua D. Simon, Matthew Shetrone +12
We present a search for new members of the 300 km s stream (300S) near the dwarf galaxy Segue 1 using wide-field survey data. We identify 11 previously unknown bright stream…
Rapid Rotation of Low-Mass Red Giants Using APOKASC: A Measure of Interaction Rates on the Post-main-sequence
Jamie Tayar, Tugdual Ceillier, D. A. GarcÃa-Hernández +16
We investigate the occurrence rate of rapidly rotating (10 km s), low-mass giant stars in the APOGEE-Kepler (APOKASC) fields with asteroseismic mass and surface…
Analysis of Detached Eclipsing Binaries near the Turnoff of the Open Cluster NGC 7142
Eric L. Sandquist, Matthew Shetrone, Andrew W. Serio +1
We analyze extensive BVRI photometry and radial velocity measurements for three double-lined deeply-eclipsing binary stars in the field of the old open cluster NGC 7142. The short…
Detailed Composition of Starts in Dwarf Spheroidal Galaxies
Matthew Shetrone
A refereed review paper which covers high resolution abundances in dSph galaxies.
The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data
Abdurro'uf, Katherine Accetta, Conny Aerts +337
This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete…
SDSS-III/APOGEE: Detailed Abundances of Galactic Star Clusters
Peter M Frinchaboy, Gail Zasowski, Kelly Jackson +4
The Sloan Digital Sky Survey III/Apache Point Observatory Galactic Evolution Experiment (SDSS-III/APOGEE) is a large-scale spectroscopic survey of Galactic stars and star clusters.…
Chemical Cartography with APOGEE: Multi-element abundance ratios
David H. Weinberg, Jon A. Holtzman, Sten Hasselquist +25
We map the trends of elemental abundance ratios across the Galactic disk, spanning R = 3-15 kpc and midplane distance |Z|= 0-2 kpc, for 15 elements in a sample of 20,485 stars meas…
Testing the Asteroseismic Mass Scale Using Metal-Poor Stars Characterized with APOGEE and Kepler
Courtney R. Epstein, Yvonne P. Elsworth, Jennifer A. Johnson +29
Fundamental stellar properties, such as mass, radius, and age, can be inferred using asteroseismology. Cool stars with convective envelopes have turbulent motions that can stochast…
The LIGO HET Response (LIGHETR) Project to Discover and Spectroscopically Follow Optical Transients Associated with Neutron Star Mergers
M. J. Bustamante-Rosell, Greg Zeimann, J. Craig Wheeler +20
The LIGO HET Response (LIGHETR) project is an enterprise to follow up optical transients (OT) discovered as gravitational wave merger sources by the LIGO/Virgo collaboration (LVC).…
Homogeneous Analysis of Globular Clusters from the APOGEE Survey with the BACCHUS Code III. Cen
Szabolcs Mészáros, Thomas Masseron, José G. Fernández-Trincado +18
We study the multiple populations of Cen by using the abundances of Fe, C, N, O, Mg, Al, Si, K, Ca, and Ce from the high-resolution, high signal-to-noise (S/N70) spectra of…
Bayesian distances and extinctions for giants observed by Kepler and APOGEE
ThaÃse S. Rodrigues, Léo Girardi, Andrea Miglio +30
We present a first determination of distances and extinctions for individual stars in the first release of the APOKASC catalogue, built from the joint efforts of the Apache Point O…
Chemical Abundance Variations in Globular Clusters: Recent Results from Mildly Metal-Poor M5
Inese I. Ivans, Robert P. Kraft, Chris Sneden +3
We present a chemical composition analysis of 36 giant stars in mildly metal-poor globular cluster M5. In comparing the M5 results to those obtained in M4, a cluster previously con…
Chemical Cartography with APOGEE: Metallicity Distribution Functions and the Chemical Structure of the Milky Way Disk
Michael R. Hayden, Jo Bovy, Jon A. Holtzman +32
Using a sample of 69,919 red giants from the SDSS-III/APOGEE Data Release 12, we measure the distribution of stars in the [/Fe] vs. [Fe/H] plane and the metallicity distributio…
Ten Year Review of Queue Scheduling of the Hobby-Eberly Telescope
Matthew Shetrone, Mark E. Cornell, James R. Fowler +10
This paper presents a summary of the first 10 years of operating the Hobby-Eberly Telescope (HET) in queue mode. The scheduling can be quite complex but has worked effectively for…
HD 91669b: A New Brown Dwarf Candidate from the McDonald Observatory Planet Search
Robert A. Wittenmyer, Michael Endl, William D. Cochran +4
We report the detection of a candidate brown dwarf orbiting the metal-rich K dwarf HD 91669, based on radial-velocity data from the McDonald Observatory Planet Search. HD 91669b is…
The stellar population structure of the Galactic disk
Jo Bovy, Hans-Walter Rix, Edward F. Schlafly +4
The spatial structure of stellar populations with different chemical abundances in the Milky Way contains a wealth of information on Galactic evolution over cosmic time. We use dat…
Disentangling the Galactic Halo with APOGEE: I. Chemical and Kinematical Investigation of Distinct Metal-Poor Populations
Christian R. Hayes, Steven R. Majewski, Matthew Shetrone +21
We find two chemically distinct populations separated relatively cleanly in the [Fe/H] - [Mg/Fe] plane, but also distinguished in other chemical planes, among metal-poor stars (pri…
BACCHUS Analysis of Weak Lines in APOGEE Spectra (BAWLAS)
Christian R. Hayes, Thomas Masseron, Jennifer Sobeck +11
Elements with weak and blended spectral features in stellar spectra are challenging to measure and require specialized analysis methods to precisely measure their chemical abundanc…
The Lazy Giants: APOGEE Abundances Reveal Low Star Formation Efficiencies in the Magellanic Clouds
David L. Nidever, Sten Hasselquist, Christian R. Hayes +28
We report the first APOGEE metallicities and alpha-element abundances measured for 3600 red giant stars spanning a large radial range of both the Large (LMC) and Small Magellanic C…
The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
Steven R. Majewski, Ricardo P. Schiavon, Peter M. Frinchaboy +75
The Apache Point Observatory Galactic Evolution Experiment (APOGEE), one of the programs in the Sloan Digital Sky Survey III (SDSS-III), has now completed its systematic, homogeneo…
The Open Cluster Chemical Analysis and Mapping Survey: Local Galactic Metallicity Gradient with APOGEE using SDSS DR10
Peter M. Frinchaboy, Benjamin Thompson, Kelly M. Jackson +31
The Open Cluster Chemical Analysis and Mapping (OCCAM) Survey aims to produce a comprehensive, uniform, infrared-based dataset for hundreds of open clusters, and constrain key Gala…
Very Metal-poor Stars in the Outer Galactic Bulge Found by the Apogee Survey
Ana E. GarcÃa Pérez, Katia Cunha, Matthew Shetrone +27
Despite its importance for understanding the nature of early stellar generations and for constraining Galactic bulge formation models, at present little is known about the metal-po…
APOKASC-3: The Third Joint Spectroscopic and Asteroseismic catalog for Evolved Stars in the Kepler Fields
Marc H. Pinsonneault, Joel C. Zinn, Jamie Tayar +38
In the third APOKASC catalog, we present data for the complete sample of 15,808 evolved stars with APOGEE spectroscopic parameters and Kepler asteroseismology. We used ten independ…
Chemical Cartography with APOGEE: Mapping Disk Populations with a Two-Process Model and Residual Abundances
David H. Weinberg, Jon A. Holtzman, Jennifer A. Johnson +33
We apply a novel statistical analysis to measurements of 16 elemental abundances in 34,410 Milky Way disk stars from the final data release (DR17) of APOGEE-2. Building on recent w…
Constraining Metallicity-dependent Mixing and Extra Mixing using [C/N] in Alpha-Rich Field Giants
Matthew Shetrone, Jamie Tayar, Jennifer A. Johnson +11
Internal mixing on the giant branch is an important process which affects the evolution of stars and the chemical evolution of the galaxy. While several mechanisms have been propos…
The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-III
Shadab Alam, Franco D. Albareti, Carlos Allende Prieto +271
The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fib…
Detailed Chemical Abundances for a Benchmark Sample of M Dwarfs from the APOGEE Survey
Diogo Souto, Katia Cunha, Verne V. Smith +16
Individual chemical abundances for fourteen elements (C, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, and Ni) are derived for a sample of M-dwarfs using high-resolution near-infrar…
Chemical abundances in the globular clusters NGC 5024 and NGC 5466 from optical and infrared spectroscopy
Masen Lamb, Kim Venn, Matthew Shetrone +2
Detailed chemical abundances for five stars in two Galactic globular clusters, NGC 5466 and NGC 5024, are presented from high resolution optical (from the Hobby- Eberley Telescope)…
Chemical tagging with APOGEE: Discovery of a large population of N-rich stars in the inner Galaxy
Ricardo P. Schiavon, Olga Zamora, Ricardo Carrera +42
Formation of globular clusters (GCs), the Galactic bulge, or galaxy bulges in general, are important unsolved problems in Galactic astronomy. Homogeneous infrared observations of l…
The Data Reduction Pipeline for the Apache Point Observatory Galactic Evolution Experiment
David L. Nidever, Jon A. Holtzman, Carlos Allende Prieto +17
The Apache Point Observatory Galactic Evolution Experiment (APOGEE), part of the Sloan Digital Sky Survey III, explores the stellar populations of the Milky Way using the Sloan 2.5…
APOGEE [C/N] Abundances Across the Galaxy: Migration and Infall from Red Giant Ages
Sten Hasselquist, Jon A. Holtzman, Matthew Shetrone +14
We present [C/N]-[Fe/H] abundance trends from the SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey, Data Release 14 (DR14), for red giant branch stars…
The Stars of the HETDEX Survey. I. Radial Velocities and Metal-Poor Stars from Low-Resolution Stellar Spectra
Keith Hawkins, Greg Zeimann, Chris Sneden +18
The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is an unbiased, massively multiplexed spectroscopic survey, designed to measure the expansion history of the universe thr…
Two Groups of Red Giants with Distinct Chemical Abundances in the Bulge Globular Cluster NGC 6553 Through the Eyes of APOGEE
Baitian Tang, Roger E. Cohen, Doug Geisler +18
Multiple populations revealed in globular clusters (GCs) are important windows to the formation and evolution of these stellar systems. The metal-rich GCs in the Galactic bulge are…
Discovery of a Dynamical Cold Point in the Heart of the Sagittarius dSph Galaxy with Observations from the APOGEE Project
Steven R. Majewski, Sten Hasselquist, Ewa L. Åokas +30
The dynamics of the core of the Sagittarius (Sgr) dwarf spheroidal (dSph) galaxy are explored using high-resolution (R~22,500), H-band, near-infrared spectra of over 1,000 giant st…
Carbon enrichment in APOGEE disk stars as evidence of mass transfer in binaries
Steve Foster, Ricardo P. Schiavon, Denise B. de Castro +10
Carbon abundances in first-ascent giant stars are usually lower than those of their main-sequence counterparts. At moderate metallicities, stellar evolution of single stars cannot…
APOGEE Data and Spectral Analysis from SDSS Data Release 16: Seven Years of Observations Including First Results from APOGEE-South
Henrik Jönsson, Jon A. Holtzman, Carlos Allende Prieto +20
The spectral analysis and data products in Data Release 16 (DR16; December 2019) from the high-resolution near-infrared APOGEE-2/SDSS-IV survey are described. Compared to the previ…
Chemical tagging can work: Identification of stellar phase-space structures purely by chemical-abundance similarity
David W. Hogg, Andrew R. Casey, Melissa Ness +10
Chemical tagging promises to use detailed abundance measurements to identify spatially separated stars that were in fact born together (in the same molecular cloud), long ago. This…
The Chemical Abundances of Stars in the Halo (CASH) Project. II. A Sample of 16 Extremely Metal-poor Stars
Julie K. Hollek, Anna Frebel, Ian U. Roederer +5
We present a comprehensive abundance analysis of 20 elements for 16 new low-metallicity stars from the Chemical Abundances of Stars in the Halo (CASH) project. The abundances have…
The Tenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Apache Point Observatory Galactic Evolution Experiment
Christopher P. Ahn, Rachael Alexandroff, Carlos Allende Prieto +232
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 da…
SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems
Daniel J. Eisenstein, David H. Weinberg, Eric Agol +237
Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological…
The NIR Ca II triplet at low metallicity - Searching for extremely low-metallicity stars in classical dwarf galaxies
Else Starkenburg, Vanessa Hill, Eline Tolstoy +9
The NIR Ca II triplet absorption lines have proven to be an important tool for quantitative spectroscopy of individual red giant branch stars in the Local Group, providing a better…
Spectrum Syntheses of High Resolution Integrated Light Spectra of Galactic Globular Clusters
Charli M. Sakari, Matthew Shetrone, Kim Venn +2
Spectrum syntheses for three elements (Mg, Na, and Eu) in high-resolution integrated light spectra of the Galactic globular clusters 47 Tuc, M3, M13, NGC 7006, and M15 are presente…
Chemical Abundances of Main-Sequence, Turnoff, Subgiant and red giant Stars from APOGEE spectra II: Atomic Diffusion in M67 Stars
Diogo Souto, C. Allende Prieto, Katia Cunha +14
Chemical abundances for 15 elements (C, N, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, Fe, and Ni) are presented for 83 stellar members of the 4 Gyr old solar-metallicity open cluster…
Abundances, Stellar Parameters, and Spectra From the SDSS-III/APOGEE Survey
Jon A. Holtzman, Matthew Shetrone, Jennifer A. Johnson +39
The SDSS-III/APOGEE survey operated from 2011-2014 using the APOGEE spectrograph, which collects high-resolution (R~22,500), near-IR (1.51-1.70 microns) spectra with a multiplexing…
Metallicity and -element Abundance Gradients along the Sagittarius Stream as Seen by APOGEE
Christian R. Hayes, Steven R. Majewski, Sten Hasselquist +27
Using 3D positions and kinematics of stars relative to the Sagittarius (Sgr) orbital plane and angular momentum, we identify 166 Sgr stream members observed by the Apache Point Obs…
Chemical Abundances of M-dwarfs from the APOGEE Survey. I. The Exoplanet Hosting Stars Kepler-138 and Kepler-186
Diogo Souto, Katia Cunha, D. A. Garcia-Hernandez +18
We report the first detailed chemical abundance analysis of the exoplanet-hosting M-dwarf stars Kepler-138 and Kepler-186 from the analysis of high-resolution ( 22,500) $…
Spectroscopy of Blue Stragglers and Turnoff Stars in M67 (NGC 2682)
Matthew Shetrone, Eric Sandquist
We have analyzed high-resolution spectra of relatively cool blue stragglers and main sequence turnoff stars in the old open cluster M67 (NGC 2682). We attempt to identify blue stra…
Two New Long-Period Giant Planets from the McDonald Observatory Planet Search and Two Stars with Long-Period Radial Velocity Signals Related to Stellar Activity Cycles
Michael Endl, Erik J. Brugamyer, William D. Cochran +16
We report the detection of two new long-period giant planets orbiting the stars HD 95872 and HD 162004 (psi1 Draconis B) by the McDonald Observatory planet search. The planet HD 95…
Chemical Cartography with APOGEE: Large-scale Mean Metallicity Maps of the Milky Way
Michael R. Hayden, Jon A. Holtzman, Jo Bovy +27
We present Galactic mean metallicity maps derived from the first year of the SDSS-III APOGEE experiment. Mean abundances in different zones of Galactocentric radius (0 < R < 15 kpc…
Discovery of Two Rare Rigidly-Rotating Magnetosphere Stars in the APOGEE Survey
Stephen S. Eikenberry, S. Drew Chojnowski, John Wisniewski +19
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) - one of the Sloan Digital Sky Survey III programs -- is using near-infrared spectra of red giant…
Bright Variable Stars in NGC 6819 - An Open Cluster in the Kepler Field
Antonio Talamantes, Eric L. Sandquist, James L. Clem +3
We describe a variability study of the moderately old open cluster NGC 6819. We have detected 4 new detached eclipsing binaries near the cluster turnoff (one of which may be in a t…
APOGEE Chemical Abundance Patterns of the Massive Milky Way Satellites
Sten Hasselquist, Christian R. Hayes, Jianhui Lian +42
The SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey has obtained high-resolution spectra for thousands of red giant stars distributed among the massi…
OCCAM X. Neutron Capture Abundances with Keck/HIRES & Magellan/MIKE
Natalie R. Myers, Peter M. Frinchaboy, Henrique Reggiani +10
The chemistry of stars provides powerful insight into the history of the Milky Way. With multiple large-sky spectroscopic surveys that are currently available, using chemistry as a…
The APOGEE-2 Survey of the Orion Star Forming Complex: I. Target Selection and Validation with early observations
J'Neil Cottle, Kevin R. Covey, Genaro Suárez +26
The Orion Star Forming Complex (OSFC) is a central target for the APOGEE-2 Young Cluster Survey. Existing membership catalogs span limited portions of the OSFC, reflecting the diff…
Chemical abundance gradients from open clusters in the Milky Way disk: results from the APOGEE survey
Katia Cunha, Peter M. Frinchaboy, Diogo Souto +23
Metallicity gradients provide strong constraints for understanding the chemical evolution of the Galaxy. We report on radial abundance gradients of Fe, Ni, Ca, Si, and Mg obtained…
Stellar Characterization of M-dwarfs from the APOGEE Survey: A Calibrator Sample for the M-dwarf Metallicities
Diogo Souto, Katia Cunha, Verne V. Smith +18
We present spectroscopic determinations of the effective temperatures, surface gravities and metallicities for 21 M-dwarfs observed at high-resolution (R 22,500) in the \tex…
The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) Survey Design, Reductions, and Detections
Karl Gebhardt, Erin Mentuch Cooper, Robin Ciardullo +60
We describe the survey design, calibration, commissioning, and emission-line detection algorithms for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The goal of HETDEX…
Chemical tagging in the SDSS-III/APOGEE survey: new identifications of halo stars with globular cluster origins
Sarah Martell, Matthew Shetrone, Sara Lucatello +6
We present new identifications of five red giant stars in the Galactic halo with chemical abundance patterns that indicate they originally formed in globular clusters. Using data f…
Optimal Integrated Abundances for Chemical Tagging of Extragalactic Globular Clusters
Charli M. Sakari, Kim Venn, Matthew Shetrone +2
High resolution integrated light (IL) spectroscopy provides detailed abundances of distant globular clusters whose stars cannot be resolved. Abundance comparisons with other system…
Young alpha-enriched giant stars in the solar neighbourhood
Marie Martig, Hans-Walter Rix, Victor Silva Aguirre +31
We derive age constraints for 1639 red giants in the APOKASC sample for which seismic parameters from Kepler, as well as effective temperatures, metallicities and [alpha/Fe] values…
L Dwarfs Found in Sloan Digital Sky Survey Commissioning Data II. Hobby-Eberly Telescope Observations
Donald P. Schneider, Gillian R. Knapp, Suzanne L. Hawley +21
Low dispersion optical spectra have been obtained with the Hobby-Eberly Telescope of 22 very red objects found in early imaging data from the Sloan Digital Sky Survey. The objects…
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
Bela Abolfathi, D. S. Aguado, Gabriela Aguilar +344
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourtee…
Chemical Abundances of Main-Sequence, Turn-off, Subgiant and red giant Stars from APOGEE spectra I: Signatures of Diffusion in the Open Cluster M67
Diogo Souto, Katia Cunha, Verne V. Smith +21
Detailed chemical abundance distributions for fourteen elements are derived for eight high-probability stellar members of the solar metallicity old open cluster M67 with an age of…
Chemical Abundances in a Sample of Red Giants in the Open Cluster NGC 2420 from APOGEE
Diogo Souto, Katia Cunha, Verne Smith +20
NGC 2420 is a 2 Gyr-old well-populated open cluster that lies about 2 kpc beyond the solar circle, in the general direction of the Galactic anti-center. Most previous abundan…
Distribution of Europium in The Milky Way Disk; Its Connection to Planetary Habitability and The Source of The R-Process
Evan M. Carrasco, Matthew Shetrone, Francis Nimmo +3
The energy provided in the radioactive decay of thorium (Th) and uranium (U) isotopes, embedded in planetary mantles, sustains geodynamics important for surface habitability such a…
The APOKASC Catalog: An Asteroseismic and Spectroscopic Joint Survey of Targets in the Kepler Fields
Marc H. Pinsonneault, Yvonne Elsworth, Courtney Epstein +42
We present the first APOKASC catalog of spectroscopic and asteroseismic properties of 1916 red giants observed in the Kepler fields. The spectroscopic parameters provided from the…
Light-Element Abundance Variations at Low Metallicity: the Globular Cluster NGC 5466
Matthew Shetrone, Sarah L. Martell, Rachel Wilkerson +4
We present low-resolution (R~850) spectra for 67 asymptotic giant branch (AGB), horizontal branch and red giant branch (RGB) stars in the low-metallicity globular cluster NGC 5466,…
The Apache Point Observatory extra-Galactic Evolution Experiment (APOeGEE): Chemical Abundance Trends for Seven Dwarf Spheroidal Galaxies in the APOGEE Survey
Matthew Shetrone, Rachael L. Beaton, Christian R. Hayes +10
In addition to comprehensive surveys of the Milky Way bulge, disk, and halo, the Apache Point Galactic Evolution Experiment (APOGEE) project observed seven dwarf spheroidal satelli…
Extending the [C/N]-Age Calibration: Using Globular Clusters to Explore Older and Metal-Poor Populations
Taylor Spoo, Katelyn Thomas, Ellie "Kaleo" Toguchi-Tani +8
In the coming years, detailed chemical abundances from large-scale high-resolution spectroscopic surveys will become available for vast numbers of stars across the Milky Way. Previ…
The Second APOKASC Catalog: The Empirical Approach
Marc H. Pinsonneault, Yvonne P. Elsworth, Jamie Tayar +33
We present a catalog of stellar properties for a large sample of 6676 evolved stars with APOGEE spectroscopic parameters and \textit{Kepler} asteroseismic data analyzed using five…
The Puzzling Li-rich Red Giant Associated with NGC 6819
Joleen K. Carlberg, Verne V. Smith, Katia Cunha +13
A Li-rich red giant star (2M19411367+4003382) recently discovered in the direction of NGC 6819 belongs to the rare subset of Li-rich stars that have not yet evolved to the luminosi…
Tracing chemical evolution over the extent of the Milky Way's Disk with APOGEE Red Clump Stars
David L. Nidever, Jo Bovy, Jonathan C. Bird +40
We employ the first two years of data from the near-infrared, high-resolution SDSS-III/APOGEE spectroscopic survey to investigate the distribution of metallicity and alpha-element…
Chemical Abundances of the Leo II Dwarf Galaxy
Matthew Shetrone, Michael H. Siegel, David O. Cook +1
We use previously-published moderate-resolution spectra in combination with stellar atmosphere models to derive the first measured chemical abundance ratios in the Leo II dSph gala…
The Bulge Metallicity Distribution from the APOGEE Survey
Ana E. Garcia Perez, Melissa Ness, Annie C. Robin +14
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) provides spectroscopic information of regions of the inner Milky Way inaccessible to optical surveys. We present…
A Photometric Study of Globular Clusters Observed by the APOGEE Survey
Szabolcs Mészáros, D. A. GarcÃa-Hernández, Santi Cassisi +8
In this paper we describe the photometric and spectroscopic properties of multiple populations in seven northern globular clusters. In this study we employ precise ground based pho…
Nucleosynthesis and the Inhomogeneous Chemical Evolution of the Carina Dwarf Galaxy
Kim Venn, Matthew Shetrone, Mike Irwin +12
The detailed abundances of 23 elements in nine bright RGB stars in the Carina dSph are presented based on high resolution spectra gathered at the VLT and Magellan telescopes. A sph…
APOGEE Data Releases 13 and 14: Stellar Parameter and Abundance Comparisons With Independent Analyses
Henrik Jönsson, Carlos Allende Prieto, Jon A. Holtzman +18
Data from the SDSS-IV / Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) have been released as part of SDSS Data Releases 13 (DR13) and 14 (DR14). These include hi…
The APOGEE red-clump catalog: Precise distances, velocities, and high-resolution elemental abundances over a large area of the Milky Way's disk
Jo Bovy, David L. Nidever, Hans-Walter Rix +48
The Sloan Digital Sky Survey III's Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a high-resolution near-infrared spectroscopic survey covering all of the major…
Final Targeting Strategy for the SDSS-IV APOGEE-2S Survey
Felipe A. Santana, Rachael L. Beaton, Kevin R. Covey +43
APOGEE is a high-resolution (R sim 22,000), near-infrared, multi-epoch, spectroscopic survey of the Milky Way. The second generation of the APOGEE project, APOGEE-2, includes an ex…