2WHSP: Catalog of 1,691 High Synchrotron Peaked Blazars and Candidates

A catalog of 1,691 High Synchrotron Peaked blazars and candidates, assembled by cross-matching multi-wavelength surveys and applying spectral slope criteria. The 2WHSP sample was created by the authors of the referenced paper and ingested by NASA's HEASARC in February 2017. It is described as the largest and most complete list of HSP blazars available to date.

Use Cases

• Identify promising high-energy gamma-ray source candidates based on spectral energy distribution (SED) peak frequencies.
• Study population properties of blazars based on infrared colors, synchrotron peak, and redshift distributions mentioned in the description.
• Provide seed sources for discovering new very high energy objects within Fermi-LAT data.
• Look for counterparts of neutrino and ultra-high energy cosmic ray sources based on the catalog's multi-wavelength associations.

Strengths

• Contains 1,691 sources, making it the largest catalog of its type described.
• Includes 288 newly identified HSPs, 540 previously known HSPs, and 814 HSP candidates.
• Sources were validated using the ASDC SED tool, requiring a synchrotron peak frequency > 10^15 Hz.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.

Provenance

Source

National Aeronautics and Space Administration (NASA HEASARC), based on CDS Catalog J/A+A/598/A17.

Collection Method

Cross-matched multi-wavelength surveys (radio, infrared, X-ray) and applied selection criteria based on spectral slopes.

Time Range

null

Freshness

Last updated 2026-03-13 18:30:10.985047; freshness should be verified.

Geography

null