SDSS BAL Quasars Catalog: 4,784 Quasars from Data Release 3

4,784 unique broad absorption line quasars were identified from the Sloan Digital Sky Survey's third data release using an automated continuum-matching algorithm. The catalog, created by NASA HEASARC in July 2008, characterizes quasars through indices like balnicity and absorption, and parameters including trough width and outflow velocity. It is derived from samples of 16,883 quasars for C IV analysis and 34,973 quasars for Mg II analysis.

Use Cases

• Classifying quasars based on broad absorption line features like the balnicity index (BI) and absorption index (AI).
• Analyzing spectral properties such as trough width, outflow velocity, and fractional depth mentioned in the description.
• Comparing emission line characteristics between BAL quasars and other quasar populations.
• Studying the prevalence of C IV and Mg II absorption across different redshift ranges (1.7 <= z <= 4.38 and 0.5 <= z <= 2.15).

Strengths

• Contains 4,784 unique quasars, providing a substantial sample for analysis.
• Uses a defined automated algorithm with specific thresholds (e.g., 10% below continuum over 1000 km/s) for consistent identification.
• Characterizes objects with multiple indices (BI, AI) and parameters (width, velocity, depth, trough count).

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Last updated 2026-03-13 18:49:11.435044; freshness should be verified.

Provenance

Source

Sloan Digital Sky Survey (SDSS), NASA HEASARC

Collection Method

Automated algorithm applied to template-matched quasar spectra from SDSS DR3.

Time Range

Based on Sloan Digital Sky Survey Data Release 3.

Freshness

Last updated 2026-03-13 18:49:11.435044; freshness should be verified.

Geography

Astronomical survey data; spatial coverage is celestial.