The Tenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Apache Point Observatory Galactic Evolution Experiment

TL;DR

The paper presents SDSS-III Data Release 10 (DR10), the tenth public SDSS data release, which combines the first public APOGEE infrared spectroscopic data with extended BOSS optical spectra through 2012. It details the APOGEE instrumentation, target selection, data processing, stellar parameter determination via ASPCAP, and data products, along with a new BOSS quasar target class and updates to data processing and galaxy population analyses. DR10 is cumulative and provides extensive data products, flags, and cross-survey integrations (e.g., APOKASC), enabling large-scale Galactic archaeology and cosmological studies. The release sets the stage for ongoing SDSS-III progress and outlines future data releases and the transition to SDSS-IV, including APOGEE-2, MaNGA, and eBOSS, to expand Milky Way mapping, galaxy science, and cosmology.

Abstract

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 microns. 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 square degrees.

Figures (15)

• Figure 1: The distribution on the sky of all APOGEE DR10 pointings in Galactic coordinates: the Galactic Center is in the middle of the diagram. Each circle represents a pointing. APOGEE often has several distinct plates for a single location on the sky; DR10 includes 170 locations, which are shown above. Smaller circles (primarily near the Galactic Center) represent locations where plates were drilled over only a fraction of the 7 deg$^2$ focal plane to minimize differential atmospheric refraction. Note the concentration of fields along the Galactic Plane. The concentration of pointings at $l= 75^\circ, b= +15^\circ$ is a special program targeting stars observed by the Kepler telescope; see Section \ref{['sec:apogee_apokasc']}. (top) Distribution of pointings in both the commissioning and survey phases (both are included in DR10). (bottom) Pointings distinguished by the number of visits obtained by DR10 in the survey phase.
• Figure 2: The distribution on the sky of all SDSS imaging (top; 14,555 deg$^2$ -- same as DR8 and DR9) and BOSS and APOGEE DR10 spectroscopy (bottom; 6373.2 deg$^2$) in J2000 equatorial coordinates ($\alpha=0^\circ$ is right of center in this projection). Grey shows regions included in DR9; the increment included in DR10 is in red. The blue shows the positions of APOGEE pointings included in DR10. The Galactic Plane is shown by the dotted line. The Northern Galactic Cap is on the left of the figure, and the Southern Galactic Cap on the right. The BOSS sky coverage shown is actually constructed using a random subsample of the BOSS DR10Q quasar catalog Paris13. The sky below $\delta<-30^\circ$ is never at an airmass of of less than 2.0 from APO (latitude=+32$^\circ$46$^\prime$49$^{\prime\prime}$).
• Figure 3: (top) A 2D spectrogram from the APOGEE instrument. The three chips ("blue", "green", and "red") are shown with wavelength increasing to the right across the full APOGEE wavelength range of 1.514--1.696 $\mu$m. The gaps between the chips are slightly larger than as displayed in this image. Each fiber is imaged onto several pixels (vertically). Note the vertical series of points from sky lines in each fiber, and the horizontal spectra of faint stars and sky fibers. (bottom) Expanded view of the central 18 fibers and central 6 nm of each chip.
• Figure 4: The distribution of number of spectroscopic visits for APOGEE stars included in DR10. While the bulk of stars have three or fewer visits, they may have reached our spectral S/N requirement if they are bright enough; see Figure \ref{['fig:apogee_snr_mag']}.
• Figure 5: The distribution of time between visits for APOGEE stars, useful for determining the sensitivity to radial velocity variations due to binarity. This quantity is the absolute value of the time difference for all unique pairs of visits for each star. The most prominent peaks are at one and two months.