SDSS-Chandra: 1,135 X-ray Detected Quasars Across Redshifts 0.2 to 5.4

1,135 X-ray detected quasars from the Sloan Digital Sky Survey, observed in 323 Chandra images by the Chandra Multiwavelength Project, represent 36 Msec of effective exposure. The table was created by NASA's HEASARC in April 2009 based on published research. It includes quasars in the redshift range 0.2 to 5.4, with spectroscopic redshifts for about one-third of the sample.

Use Cases

• Study the correlation between optical/UV to X-ray flux (Alpha_ox) and optical luminosity based on the reported significant correlation.
• Investigate the evolution of X-ray photon index (Gamma) and Alpha_ox across redshifts up to z ~ 5.
• Analyze the prevalence of intrinsic absorption in quasars based on the finding that ~10% have columns >10^22 cm^-2.
• Compare properties of specific subsamples like narrow-line Seyfert 1s and narrow absorption line QSOs for unusual distributions of Alpha_ox or Gamma.

Strengths

• Includes 1,135 X-ray detected quasars, a substantial sample for statistical analysis.
• Covers a broad redshift range from 0.2 to 5.4, including 56 quasars with z > 3.
• Based on 323 Chandra images and 36 Msec of effective exposure, indicating substantial observational effort.
• Provides both spectroscopic and photometric redshift estimates for the sample.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data was created in 2009; freshness should be verified for current research needs.

Provenance

Source

NASA HEASARC, based on data from the Sloan Digital Sky Survey and the Chandra Multiwavelength Project.

Collection Method

Optical selection from SDSS, followed by X-ray observation and analysis in 323 Chandra images.

Freshness

Last updated 2026-03-13 16:46:15.021354; freshness should be verified.