Technical Papers and Additional References

Table of Contents

The documentation web pages describe the key features of APOGEE observations, data analysis, and data products, but, by necessity, the pages must be concise. For the most in-depth discussions, users should consult the APOGEE technical papers. The references that are required for all uses of the APOGEE data are given in Required Refences, and our current full compilation of papers is given in All Technical Papers.

Required References

In addition to the SDSS required references and acknowledgement, all users of APOGEE data should acknowledge the following publications in papers and presentations:

The APOGEE Overview Paper: Majewski et al. (2017)
The Data Processing & Reduction Paper: Nidever et al. (2015)
The Instrument Paper: Wilson et al. (2012)
The appropriate targeting paper(s) selected from the Target Section.
The appropriate data release paper selected from the Data Release Section.

In addition, those using chemical abundances need to cite the following publications:

The ASPCAP overview paper: Garcia Perez et al. (2016)
The linelist paper: Shetrone et al. (2015)

Lastly, users should consider the list of papers below and cite those that are appropriate for their analyses.

All Technical Papers

Current Data Release Papers

DR15 Data Release Description: Aguado et al. (2018) is the latest SDSS data release paper, describing SDSS Data Release 15. Although APOGEE data in DR15 are identical to DR14, the latest data release paper should be used as the primary reference for most uses of SDSS data.
DR13+DR14 Pipeline and Data Release Description: Holtzman et al. (2018) provides extensive detail with regard to DR13- and DR14-related modifications of the data reduction and ASPCAP pipelines and evaluates all DRP- and ASPCAP-generated data products (e.g., radial velocity values, stellar atmospheric parameters and individual element abundances).
DR13+DR14 ASPCAP Results Assessment: Jönsson et al. (2018) compares DR13 and DR14 ASPCAP-derived parameters with a varied composite of abundance analyses from the literature.

Overview

APOGEE Overview: Majewski et al. (2017) discusses the scientific motivation for the APOGEE-1 survey, the survey requirements, and the choice of survey fields. It describes survey operations, summarizes the level to which requirements are met, and references the data releases. Much of this information remains highly relevant for APOGEE-2.

Instrument & Hardware

The APOGEE Instruments: Wilson et al. (2012) and Wilson et al. (2018, in preparation), discusses the technical details of the instrument itself and present critical instrument performance data.
VPH Grating: Arns et al. (2010) discusses the technical details of the VPH grating.
SDSS 2.5m Telescope: Gunn et al. (2006) describes the technical setup for the SDSS 2.5-meter telescope.
NMSU 1m Telescope: Holtzman et al. (2010) describes the technical setup for the NMSU 1-meter telescope.

Targeting

APOGEE-1 Target Selection

Zasowski et al. (2013) discusses the target selection for main survey and APOGEE-1 ancillary science projects.

Pinsoneault et al. (2014) provide an expanded discussion of the Kepler field targeting (APOKASC).

APOGEE-2 Target Selection

Zasowski et al. (2017) describes the APOGEE-2 field plan and explains in detail the targeting strategy employed for APOGEE-2N and APOGEE-2S.

Pinsoneault et al. (2018) provides updates to the APOKASC program in APOGEE-2.

Data Processing & RV Pipeline

APOGEE Data Reduction

Nidever et al. (2015) discusses the data reduction pipeline, describing how the raw data are analyzed to produce reduced, calibrated spectra. It also presents additional instrument performance data (flats, darks, LSF, persistence, etc.) and discusses the measurement of radial velocities and their quality.

NMSU 1-meter Data Processing

Holtzman et al. (2015) has sections discussing the 1-meter data processing, which differs slight from that in the main survey.

Radial Velocity Validation

The following papers address specific expansions or applications of our RV results that may be useful for other science applications:

Deshpande et al. (2013) discusses specific requirements for the determination of M-dwarf stars with APOGEE data.
Badenes et al. (2018) use the variation of RV for the APOGEE sample as a means to draw inference on the binary population. Technical decscriptions and testing conducted in this paper are useful for evaluating the RV precision and variability.
Price-Whelan et al. (2018) use the individual epoch RVs to identify multiple star systems. Technical decscriptions and testing conducted in this paper are useful for evaluating the RV precision and variability.

Stellar Parameters & Abundances

ASPCAP Overview

Garcia Perez et al. (2016) describes how the spectra are analyzed to derive stellar parameters and abundances. It demonstrates validation of the overall method using simulated data and discusses uncertainties that are introduced by real-world issues: SNR, issues related computational efficiency, variation and uncertainty of the LSF, and issues involving the loss of information under skylines. It presents some basic tests of the methodology from very-high-resolution observations of some well-studied stars.

APOGEE Model Atmospheres

Meszaros et al. (2012) discusses details of the model atmospheres that were used for the final APOGEE-1 analysis (which is included in DR14+).

APOGEE Line List

The line list used for DR10-DR15 is described in Shetrone et al. (2015) , which also presents the details of how the H-band linelists, a critical component for ASPCAP, were developed. Additional papers discussing the line list development are as follows:

The APOGEE linelists are tested using high-resolution IR spectra of several well-studied stars in Smith et al. (2013).
Further tests of the individual elements derived from the ASPCAP pipeline are found in Cunha et al. (2015).
The identification and characterization of Neodymium is described in Hasselquist et al. (2016).
The identification and characterization of Cerium is described Cunha et al. (2017)

APOGEE Spectral Grids

Zamora et al. (2015) presents how the spectral synthesis was done, documents the libraries that have been used, and investigates the sensitivity of the result to the choice of synthesis code and model atmospheres.

FERRE

Allende Prieto et al. (2006) describes FERRE, which is the spectral fitting engine used for ASPCAP. The code is available on github with its own documentation available (pdf; updated regularly).

The Cannon

The Cannon is described in Ness et al. (2015) and Casey et al. (2016).

Data Release Papers

APOGEE DR10 Calibration: Meszaros et al. (2013) discusses calibration of stellar parameters that were released in DR10.
APOGEE DR12 Data: Holtzman et al. (2015) describes the APOGEE data contained DR12 of in SDSS-III.
APOGEE DR13/DR14 Data: Holtzman et al. (in press at AJ), provides extensive detail with regard to DR13- and DR14-related modifications of the data reduction and ASPCAP pipelines and evaluates all DRP- and ASPCAP-generated data products (e.g., radial velocity values, stellar atmospheric parameters and individual element abundances).
DR13/DR14 Validation: Jönsson et al. (in press at AJ), compares DR13 and DR14 ASPCAP-derived parameters with various optical abundance analyses from the literature.