Stripe 82-XL: The ∼54.8 deg2 and ∼18.8 Ms Chandra and XMM-Newton Point-source Catalog and Number of Counts

Abstract

We present an enhanced version of the publicly available Stripe 82X catalog (S82-XL), featuring a comprehensive set of 22,737 unique X-ray point sources identified with a significance ≳4 σ . This catalog is four times larger than the original Stripe 82X catalog, by including additional archival data from the Chandra and XMM-Newton telescopes. Now covering ∼54.8 deg ^2 of nonoverlapping sky area, the S82-XL catalog roughly doubles the area and depth of the original catalog, with limiting fluxes (half-area fluxes) of 3.4 × 10 ^−16 (2.4 × 10 ^−15 ), 2.9 × 10 ^−15 (1.5 × 10 ^−14 ), and 1.4 × 10 ^−15 (9.5 × 10 ^−15 ) erg s ^−1 cm ^−2 across the soft (0.5–2 keV), hard (2–10 keV), and full (0.5–10 keV) bands, respectively. S82-XL occupies a unique region of flux-area parameter space compared to other X-ray surveys, identifying sources with rest-frame luminosities from 1.2 × 10 ^38 to 1.6 × 10 ^47 erg s ^−1 in the 2–10 keV band (median X-ray luminosity, 7.2 × 10 ^43 erg s ^−1 ), and spectroscopic redshifts up to z ∼ 6. By using hardness ratios, we derived the obscuration of active galactic nuclei (AGNs), obtaining a median value of ${\rm{log}}({N}_{{\rm{H}}}/{{\rm{cm}}}^{-2})={21.6}_{-1.6}^{+1.0}$ and an overall, obscured fraction ( ${\rm{log}}({N}_{{\rm{H}}}/{{\rm{cm}}}^{-2})\gt 22$ ) of ∼36.9%. S82-XL serves as a benchmark in X-ray surveys and, with its extensive multiwavelength data, is especially valuable for comprehensive studies of luminous AGNs.

Keywords

• Active galaxies
• Active galactic nuclei
• High-luminosity active galactic nuclei
• X-ray active galactic nuclei
• X-ray surveys
• Sky surveys