WIBRALS - WISE Blazar-like Radio-Loud Source (WIBRaLS) Catalog

Overview

This table contains a catalog of radio-loud candidate gamma-ray emitting blazars with WISE mid-infrared colors similar to the colors of confirmed gamma-ray blazars. The catalog is assembled from WISE sources detected in all four WISE filters, with colors that are compatible with the three-dimensional locus of the WISE gamma-ray emitting blazars, and which can be spatially cross-matched with radio sources from one of the three radio surveys: NVSS, FIRST, and/or SUMSS. The authors' initial WISE selection uses a slightly modified version of previously successful algorithms. They then select only the radio-loud sources using a measure of the radio-to-IR flux, the q₂₂ parameter, which is analogous to the q₂₄ parameter known in the literature but which instead uses the WISE band-four flux at 22 micron (µm). Their final catalog contains 7,855 sources classified as BL Lacs, FSRQs, or mixed candidate blazars; 1,295 of these sources can be spatially re-associated as confirmed blazars. In their paper, the authors describe the properties of the final catalog of WISE blazar-like radio-loud sources and consider possible contaminants. Finally, they discuss why this large catalog of candidate gamma-ray emitting blazars represents a new and useful resource to address the problem of finding low-energy counterparts to currently unidentified high-energy sources.

The WISE magnitudes in the [3.4], [4.6], [12] and [22] um nominal filters are in the Vega system. The values of three WISE magnitudes, namely [3.4], [4.6], and [12], and of the colors derived using those magnitudes, have been corrected for galactic extinction according to the extinction law presented by Draine (2003, ARA&A, 41, 241). In their study, the authors adopt the nomenclature proposed in the Multi-wavelength Blazar Catalog (BZCat) that labels BL Lac objects as 'BZBs' and flat-spectrum radio quasars (FSRQs) as 'BZQs'.

Catalog Bibcode

2014ApJS..215...14D

References

The WISE blazar-like radio-loud sources: an all-sky catalog of candidate
gamma-ray blazars.
    D'Abrusco R., Massaro F., Paggi A., Smith H.A., Masetti N., Landoni M.,
    Tosti G.
   <Astrophys. J. Suppl., 215, 14 (2014)>
   =2014ApJS..215...14D     (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in December 2014 based on a machine-readable version of Table 4 from the reference paper that was obtained from the ApJS web site.

Parameters

Name
The WIBRaLS catalog source designation using the 'WB' prefix and the truncated J2000.0 equatorial coordinates, e.g., 'WB J0004-4736'.

WISE_Name
The WISE designation of the source.

RA
The Right Ascension of the WISE source position in the selected equinox.

Dec
The Declination of the WISE source position in the selected equinox.

LII
The Galactic Longitude of the WISE source position.

BII
The Galactic Latitude of the WISE source position.

W1W2_Color
The WISE [3.4] - [4.6] um (w₁ - w₂) color of the source corrected for Galactic absorption.

W1W2_Color_Error
The uncertainty in the WISE [3.4] - [4.6] um (w₁ - w₂) color of the source.

W2W3_Color
The WISE [4.6] - [12] um (w₂ - w₃) color of the source corrected for Galactic absorption.

W2W3_Color_Error
The uncertainty in the WISE [4.6] - [12] um (w₂ - w₃) color of the source.

W3W4_Color
The WISE [12] - [22] um (w₃ - w₄) color of the source corrected for Galactic absorption.

W3W4_Color_Error
The uncertainty in the WISE [12] - [22] um (w₃ - w₄) color of the source.

BZB_Region_Score
The score for the BZB Region of the locus for the given source (see Section 2.1 of the reference paper for more details).

Mixed_Region_Score
The score for the Mixed Region of the locus for the given source (see Section 2.1 of the reference paper for more details).

BZQ_Region_Score
The score for the BZQ Region of the locus for the given source (see Section 2.1 of the reference paper for more details).

Blazar_Type
The spectral type of the blazar (see Section 2.1 of the reference paper for more details).

Blazar_Type_Grade
The class or grade of the blazar type, A, B, C or D. For each distinct region of the model (BZB, BZQ, or mixed), class A sources have a score s >= s_90%, class B sources have a score s of s_60% <= s < s_90_%, and class C sources have a score of s_20% <= s < s_60%, where s_20% is the 20th percentile of the score distribution, s_60% is the 60th percentile of the score distribution and s_90% is the 90th percentile of the score distribution. The meaning of class D is not explicitly stated in the paper but appears to refer to cases where an object has scores corresponding to or just below grade C in 2 regions of the locus.

Radio_Name
The name of the final radio counterpart associated with the WISE source, taken from either the NVSS, SUMSS or FIRST surveys, matched using the optimal radii established in Section 2.2 of the reference paper.

Q_22
The value of the q₂₂ parameter, defined as the logarithm of the ratio of the WISE 22-micron to the radio flux densities. The authors in general used the flux density at 1.4 GHz as the radio flux density S_radio. Since flux density measurements at 1.4 GHz are not available in the SUMSS survey, for the SUMSS counterparts, they used the flux densities at 843 MHz instead. A well known property of blazars is the flatness of their radio spectra which extends up to low radio frequencies well below 1 GHz. For this reason, the use of the flux density at 843 MHz instead of the flux density at 1.4 GHz to estimate the q₂₂ parameter negligibly affects their analysis.

Class
Browse Object Classification

Contact Person

Questions regarding the WIBRALS database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:36:46 EDT