A neural network trained on simulations infers stripping times for Sagittarius stream stars from phase-space data, measuring a 0.3 dex/Gyr metallicity gradient and estimating ages for globular clusters such as Pal 12 and NGC 2419.
The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
5 Pith papers cite this work. Polarity classification is still indexing.
5
Pith papers citing it
abstract
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, homogeneous spectroscopic survey sampling all major populations of the Milky Way. After a three year observing campaign on the Sloan 2.5-m Telescope, APOGEE has collected a half million high resolution (R~22,500), high S/N (>100), infrared (1.51-1.70 microns) spectra for 146,000 stars, with time series information via repeat visits to most of these stars. This paper describes the motivations for the survey and its overall design---hardware, field placement, target selection, operations---and gives an overview of these aspects as well as the data reduction, analysis and products. An index is also given to the complement of technical papers that describe various critical survey components in detail. Finally, we discuss the achieved survey performance and illustrate the variety of potential uses of the data products by way of a number of science demonstrations, which span from time series analysis of stellar spectral variations and radial velocity variations from stellar companions, to spatial maps of kinematics, metallicity and abundance patterns across the Galaxy and as a function of age, to new views of the interstellar medium, the chemistry of star clusters, and the discovery of rare stellar species. As part of SDSS-III Data Release 12, all of the APOGEE data products are now publicly available.
representative citing papers
Egent achieves raw agreement of MAD 5-7 mA with human experts on 18,615 spectral lines by using LLM-driven adjustments to fitting windows, blends, and continuum without post-hoc corrections.
A lithium chemical evolution model for the GSE galaxy matches survey data showing Spite-like and eRGB plateaus at low metallicity with a hint of reduced nova contributions.
Phase-space density is recovered from Gaia data for M4 and disrupted streams by correcting entropy injection and minimizing stream entropy, enabling original mass inference via Liouville's theorem.
High-precision abundances and Ba isotopic ratios in TYC 6044-714-1 favor an s+r nucleosynthesis scenario over i-process models, which require implausible conditions and mismatch isotopic data.
citing papers explorer
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Reconstructing the Stripping History of the Sagittarius Stream with Neural Networks
A neural network trained on simulations infers stripping times for Sagittarius stream stars from phase-space data, measuring a 0.3 dex/Gyr metallicity gradient and estimating ages for globular clusters such as Pal 12 and NGC 2419.
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Egent: An Autonomous Agent for Equivalent Width Measurement
Egent achieves raw agreement of MAD 5-7 mA with human experts on 18,615 spectral lines by using LLM-driven adjustments to fitting windows, blends, and continuum without post-hoc corrections.
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Gaia-Sausage-Enceladus: Lithium evolution from early red-giant-branch and main-sequence stars
A lithium chemical evolution model for the GSE galaxy matches survey data showing Spite-like and eRGB plateaus at low metallicity with a hint of reduced nova contributions.
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Applying Liouville's Theorem to Gaia Data
Phase-space density is recovered from Gaia data for M4 and disrupted streams by correcting entropy injection and minimizing stream entropy, enabling original mass inference via Liouville's theorem.
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Observational Signatures and Constraints on the Intermediate Neutron-Capture Process. The Case of the CEMP star TYC 6044-714-1 (RAVE J094921.8-161722)
High-precision abundances and Ba isotopic ratios in TYC 6044-714-1 favor an s+r nucleosynthesis scenario over i-process models, which require implausible conditions and mismatch isotopic data.