Extended Chandra Deep Field-South: Optical and Near-IR Counterparts for X-Ray Sources

A catalog of optical and near-infrared counterparts for X-ray sources detected in the Extended Chandra Deep Field-South. The table includes new spectroscopic redshifts for 283 counterparts, bringing the total number of spectroscopically identified X-ray sources to over 500 in this field. NASA HEASARC created this online catalog in November 2010 based on data from a published astrophysical journal paper.

Use Cases

• Study the luminosity-redshift plane for active galactic nuclei (AGNs) based on the described coverage.
• Identify and analyze optically faint galaxies at high redshift based on the detection of interstellar absorption lines.
• Investigate type-2 quasars at redshifts between 1 and 3.5, a sample stated to be significantly increased.
• Determine distances to galaxy groups with extended X-ray emission based on the accurate measurements mentioned.

Strengths

• Includes a high fraction (80%) of X-ray sources with secure identifications.
• Contains new spectroscopic redshifts for 283 counterparts, with measurements up to z = 4.
• Catalog incorporates both spectroscopic and photometric redshifts from published sources.

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 20:09:09.056958; freshness should be verified as the underlying observations are older.

Provenance

Source

NASA HEASARC, based on data from a published astrophysical journal paper.

Collection Method

Data acquired via deep spectroscopic exposures (2-9 hours per pointing) using VLT/VIMOS and Keck/DEIMOS telescopes, with counterparts determined by a likelihood routine.

Time Range

Observations likely span the period of the survey program, but specific years are not stated.

Freshness

Catalog last updated 2026-03-13, but based on 2010 data creation from earlier observations.

Geography

Covers the Extended Chandra Deep Field-South (E-CDF-S) astronomical survey field.