SDSS DR12Q: 297,301 Quasars with Spectra and Multi-Wavelength Properties

The Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey (BOSS) produced this catalog covering 9,376 square degrees. It contains 297,301 confirmed quasars, including 272,026 new discoveries, with redshifts, emission line data, and multi-band photometry. The catalog results from five years of observations and includes supplemental data on broad absorption line quasars and serendipitous discoveries.

Use Cases

• Train redshift estimation models based on principal component eigenspectra and emission line data.
• Identify broad absorption line quasars based on the characteristics listed in the supplemental BAL file.
• Study quasar luminosity functions using the provided M_i_[z=2] cut and five-band photometry.
• Analyze optical variability patterns using the multi-epoch photometry from SDSS and Palomar Transient Factory.
• Correlate quasar properties with multi-wavelength data from X-ray, ultraviolet, near-infrared, and radio surveys.

Strengths

• Large scale with 297,301 confirmed quasars, including 184,101 at high redshift (z > 2.15).
• Includes robust identifications and redshifts measured via principal component eigenspectra.
• Provides multi-wavelength emission properties from other large-area surveys when available.
• Contains calibrated digital spectra covering 3600-10,500 Angstroms at spectral resolution R between 1300 and 2500.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown for the main catalog file, which may limit suitability assessment.
• Description metadata is limited; actual data quality requires manual inspection after download.

Provenance

Source

Sloan Digital Sky Survey III (SDSS-III) Baryon Oscillation Spectroscopic Survey (BOSS).

Collection Method

Spectroscopic targeting of quasar candidates followed by visual inspection and confirmation.

Time Range

Covers five years of observations from the SDSS-III/BOSS survey.

Freshness

Last updated 2026-03-13 17:08:06.191841; freshness should be verified.

Geography

Observations cover 9,376 square degrees of sky.