What's New in DR10?

DR10 includes near-infrared spectra of the first 57,454 stars observed using the APOGEE spectrograph, plus 684,000 new optical spectra from the BOSS spectrograph, and new reductions and galaxy parameter fits for all of the BOSS data. The imaging data and previous data from the SDSS spectrograph are included within DR10 as well. Prior data releases have not been changed. Data from DR9 and DR8 are available on this site, and data from DR7 and before are available from the original SDSS website.

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New spectra: Apache Point Observatory Galactic Evolution Experiment (APOGEE)

SDSS Data Release 10 includes the first public release of spectroscopic data from the SDSS-III's Apache Point Observatory Galactic Evolution Experiment (APOGEE), with infrared spectra for 57,454 stars over 170 separate sight lines (known as fields or locations in APOGEE parlance). This is a complete set of the APOGEE data taken through July 2012. Each star was observed multiple times, yielding 178,397 independent visit spectra of these stars. Full documentation is available on our IR Spectra pages.

APOGEE is a large-scale survey of the detailed chemistry and kinematics of the Milky Way, with the primary goal of understanding the evolution of our home galaxy. By operating in the near-infrared H band, APOGEE peers through the interstellar dust extinction that obscures large fractions of the inner Galaxy at optical wavelengths. By using high resolution, high S/N spectra, APOGEE provides a large, uniform database of precision stellar measurements, primarily of giants, across all Galactic populations. APOGEE includes samples of halo, thin and thick disk stars, as well as stars in the central bulge and bar. The APOGEE spectral window includes numerous chemical species, including C, N, O -- the most abundant metals in the universe -- other α and odd-Z elements, as well as Fe and other iron-peak elements.

APOGEE uses a custom-built, high resolution, cryogenic spectrograph. The spectrograph was installed on-site in April 2011 and commenced survey operations in September 2011. The instrument features:

A stable optical bench contained within an environmentally-controlled, cryogenic vessel housed separately but linked to the Sloan 2.5-m telescope by a 40-meter fiber optic run.
Three 2048 x 2048 detectors recording R ~ 22,500 spectra over most of the infrared H band (1.51-1.70μm, with small gaps between detectors).
Detector dithering to improve spectral sampling with exposures taken in half-pixel-stepped dither pairs.

Using this spectrograph, APOGEE has targeted mostly giant stars distributed around our galaxy. The strategy has been to probe all regions of the Galaxy accessible from APO. A number of ancillary science projects are devoted to the astrophysics of stars, stellar and sub-stellar binary companions, star-forming regions, star clusters, and interstellar dust. Please see the documentation for the full description of the target selection procedure.

The stars observed for DR10 have had precise radial velocities and stellar parameters measured, including temperatures, gravities, metallicities, and α-element abundances. Please see the documentation on where the stellar parameters are, examples of how to access them, and how to use them wisely. For APOGEE commissioning data, only radial velocities are provided in this data release. With APOGEE spectra, it is possible to derive precise abundances for a large range of other elements, which will be the focus of the next data release at the end of 2014.

New spectra: Baryon Oscillation Spectroscopic Survey (BOSS)

BOSS is an ongoing survey whose primary science driver is to measure the baryon acoustic oscillation (BAO) feature in the clustering of galaxies and the Lyman-α forest. By the end of the survey, BOSS will measure spectra of 1.5 million galaxies to z~0.7, as well as for 160,000 quasars with redshifts between 2.2 and 3.5. Data Release 10 contains the first three years of BOSS spectroscopy (all BOSS observations between December 5, 2009 and July 2012).

In DR10, BOSS has increased its sample of spectra to 1,515,000 (from 831,000 released in DR9). In addition, all of these BOSS spectra have been rereduced using an improved pipeline. To date, there have now been 3,358,200 optical spectra taken with the SDSS and BOSS spectrographs, all of which are included in DR10.

DR10 also includes galaxy spectral analysis for all galaxies in the optical spectra, including now those spectra taken with the SDSS spectrograph. The measured parameters include stellar masses, star-formation histories, and emission line measurements. Please see the documentation on algorithms and data access.

New in SkyServer: new JPG images and catalog data tools

The SDSS imaging camera has been retired, so no new imaging data are included in DR10. However, existing SDSS imaging data has been reprocessed into new JPG images on SkyServer, resulting in an improved image quality in the Navigate tool. In addition, because APOGEE targets were selected from 2MASS infrared imaging data, those images are also available in SkyServer.

SkyServer also includes new tools designed to work with APOGEE data. The Explore tool has been heavily redesigned, and the new Infrared Spectroscopy Query Form offers menu-based searching of APOGEE data.

Lastly, SkyServer has been updated using newer web technology. This means that all pages which had the page extension .asp have been updated to use .aspx. All links on sdss3.org and SkyServer will still work, but if you have pages bookmarked, you will need to update those links.