Table · dataset · 2026
4LAC FSRQs & BL Lac objects energy distributions
Listed in IVOA Registry (Virtual Observatory)
A sample of 312 low-frequency-peaked BL Lacertae objects (LBLs) and 694 flat-spectrum radio quasars (FSRQs) with the parameters of both redshift and gamma-ray photon spectral index ({Gamma}_{gamma}_) is compiled from the Fourth Catalog of Active Galactic Nuclei Data Release 2 from the Fermi Large Area Telescope (LAT).
Description
The multiwavelength data of the sample sources are downloaded from the Space Science Data Center, and then matched to the corresponding gamma-ray data from the Fermi-LAT Fourth Source Catalog DR2.
The synchrotron radiation peak frequency and Compton dominance (CD) parameters of the sources are obtained by using a log-parabolic model to fit the average-state multiwavelength spectral energy distribution. A support vector machine in the logL_{gamma}_-{Gamma}_{gamma}_ frame is utilized to delineate the optimal boundary between FSRQs and LBL sources. The 1{sigma} position of the Gaussian fitting on the histograms of the {Gamma}_{gamma}_, log{nu}_peak_^syn^, and CD parameter distributions are also introduced.
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With this criterion, 25 FSRQ candidates are selected from LBL sample sources. The optical spectral identification result confirms that 8 out of 13 candidate sources available with the optical spectral data exhibit the relationship of EW>5{AA}.
Links
Where it is published
- Reference page cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/278/11 ↗
landing page · from IVOA Registry
Documentation and papers
- ADS 2025ApJS..278...11L ui.adsabs.harvard.edu/abs/2025ApJS..278...11L ↗
publication · from IVOA Registry
Catalogue records · 2
- VOResource record dc.g-vo.org/oai.xml?verb=GetRecord&metadataPrefix=ivo_vor&identifier=ivo%3… ↗
metadata API · from IVOA Registry
- Registry record (GAVO) dc.g-vo.org/I/cds.vizier/j/apjs/278/11 ↗
catalogue entry · from IVOA Registry
Topics
- Stated by source
- Gamma-Ray
- From keywords
- Astronomy & Astrophysics
- Inferred from text
- Astronomical sciences 71%
Provenance · 1 source records, 9 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://cds.vizier/j/apjs/278/11 | 11 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[field].anzsrc:group:5101 | enrichment · IVOA Registry | taxonomy-embedding@1.0.0 | title+keywords+description (71%) |
| concepts[field].local:field:astronomy | mapping · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].ivoa_waveband:gamma-ray | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| description | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_description |
| license_text | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| publication_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| title | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_title |
| updated_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 |