ELAIS S1 Field: X-Ray Source Optical/IR Identifications for 478 Sources

December 2008 catalog from the HEASARC contains optical and infrared identifications for 478 X-ray sources detected by XMM-Newton and Chandra in the central 0.6 deg² of the ELAIS-S1 field. The table provides photometry in ten bands from B to 24 micron, spectroscopic redshifts for 237 sources, photometric redshifts for 68, and classifications including broad-line and narrow-line active galactic nuclei. It was created by the HEASARC based on work by the National Aeronautics and Space Administration.

Use Cases

• Classify active galactic nuclei (AGN) types based on spectroscopic redshift and broad-line presence mentioned in the description
• Analyze Spectral Energy Distributions (SEDs) based on ten-band photometry from B to 24 micron
• Study the relationship between X-ray properties and optical/infrared colors for obscured and unobscured AGNs
• Validate photometric redshift techniques using the subset of 68 sources with reliable photometric redshifts
• Investigate host galaxy properties using infrared-to-optical colors and near-infrared SEDs

Strengths

• Counterpart identified for all 478 X-ray sources in the catalog
• Spectroscopic redshift and classification provided for 237 sources (~50% of the sample)
• Photometry available in ten distinct photometric bands, from B to MIPS 24 micron
• Includes 11 spectroscopically identified type 2 QSOs with detailed high-energy properties

Limitations

• Column-level documentation is absent; field semantics must be inferred after download
• Row count is unknown, which may limit suitability assessment
• Data may reflect observational bias inherent to the specific ELAIS-S1 field survey

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Optical/infrared identifications using chance coincidence probability in R and IRAC 3.6 micron bands, complemented by precise Chandra positions.

Time Range

Observational date range not specified; catalog created in December 2008.

Freshness

Last updated 2026-03-13 18:47:58.928213; freshness should be verified

Geography

Central 0.6 deg² of the ELAIS-S1 field.