The Apache Point Observatory Galactic Evolution Experiment (APOGEE) and its successor, APOGEE‐2

Abstract

The Apache Point Observatory Galactic Evolution Experiment (APOGEE) of Sloan Digital Sky Survey III (SDSS-III) has produced a large catalog of high resolution (R = 22 500), high quality (S/N > 100), infrared (H-band) spectra for stars throughout all stellar populations of the Milky Way, including in regions veiled by significant dust opacity. APOGEE's half million spectra collected on > 163 000 unique stars, with time series information via repeat visits to each star, are being applied to numerous problems in stellar populations, Galactic astronomy, and stellar astrophysics. From among the early results of the APOGEE project -which span from measurements of Galactic dynamics, to multi-element chemical maps of the disk and bulge, new views of the interstellar medium, explorations of stellar companions, the chemistry of star clusters, and the discovery of rare stellar species -I highlight a few results that demonstrate APOGEE's unique ability to sample and characterize the Galactic disk and bulge. Plans are now under way for an even more ambitious successor to APOGEE: the six-year, dual-hemisphere APOGEE-2 project. Both phases of APOGEE feature a strong focus on targets having asteroseismological measurements from either Kepler or CoRoT, from which it is possible to derive relatively precise stellar ages. The combined APOGEE and APOGEE-2 databases of stellar chemistry, dynamics and ages constitute an unusually comprehensive, systematic and homogeneous resource for constraining models of Galactic evolution.

NGC 6535: the lowest mass Milky Way globular cluster with a Na-O anti-correlation?

“…involving C, N), whenever no high-resolution spectroscopy was available for the particular cluster. For the OCs, we only considered a subsample: the two old, massive OCs Berkeley 39 and NGC 6791 3 observed and analyzed homogeneously by us , five OCs in the Gaia-ESO Survey (Gilmore et al 2012), one in APOGEE (Majewski et al 2016), and four more from different groups. While not exhaustive, the OC list comprises only clusters in which large samples of stars were analysed; for more data on OCs and MPs, see MacLean et al (2015); Krause et al (2016).…”

Target Selection for the SDSS-IV APOGEE-2 Survey

“…The APOGEE-2 survey (Majewski et al 2016), part of SDSS-IV (2014-2020; Blanton et al 2017), expands and significantly enhances the original APOGEE sample, with the key addition of a second spectrograph at Las Campanas Observatory (LCO) to make a unique all-sky H-band spectroscopic survey. APOGEE-2 thus comprises two complementary components: APOGEE-2 North (APOGEE-2N), using the Sloan Foundation 2.5 m telescope at APO (Gunn et al 2006) and original APOGEE spectrograph (Wilson et al 2012), and APOGEE-2 South (APOGEE-2S), using the du Pont 2.5 m telescope at LCO and a cloned spectrograph.…”

Chemical Evolution Library for Galaxy Formation Simulation

“…There are many galactic surveys which resolve the chemical compositions and kinematic information of a lot of stars, e.g., RAVE (Steinmetz et al 2006), APOGEE (Majewski et al 2016), Gaia-ESO (Gilmore et al 2012), HERMES (GRASH) (De Silva et al 2015). The data obtained by these surveys can make a strong constraint on the formation and evolution of the Milky Way galaxy and thus, it becomes a clue to understanding the formation and evolution of galaxies in general.…”