Optical spectroscopic observations of blazars and gamma-ray blazar candidates in the Sloan Digital Sky Survey Data Release Nine

Abstract

We present an analysis of the optical spectra available in the Sloan Digital Sky survey data release nine (SDSS DR9) for the blazars listed in the ROMA-BZCAT and for the gamma-ray blazar candidates selected according to their IR colors. First, we adopt a statistical approach based on MonteCarlo simulations to find the optical counterparts of the blazarslisted in the ROMA-BZCAT catalog. Then we crossmatched the SDSS spectroscopic catalog with our selected samples of blazars and gamma-ray blazar candidates searching for those with optical spectra available to classify our blazar-like sources and, whenever possible, to confirm their redshifts. Our main objectives are determining the classification of uncertain blazars listed in the ROMA-BZCAT and discovering new gamma-ray blazars. For the ROMA-BZCAT sources we investigated a sample of 84 blazars confirming the classification for 20 of them and obtaining 18 new redshift estimates. For the gamma-ray blazars, indicated as potential counterparts of unassociated Fermi sources or with uncertain nature, we established the blazar-like nature of 8 out the 27 sources analyzed and confirmed 14 classifications.

arXiv comment7 pages, 2 figures, 4 tables, AJ published in 2014 (pre-proof version)

References in corpus (34)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Unified Schemes for Radio-Loud Active Galactic Nuclei
• The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey
• Fermi Large Area Telescope Second Source Catalog
• Fermi Large Area Telescope First Source Catalog
• The Second Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• Roma-BZCAT: A multifrequency catalogue of Blazars
• Simultaneous Planck, Swift, and Fermi observations of X-ray and gamma-ray selected blazars
• The Fermi-LAT high-latitude Survey: Source Count Distributions and the Origin of the Extragalactic Diffuse Background
• Identification of the infrared non-thermal emission in Blazars
• The RGB Sample of Intermediate BL Lacs
• The WISE gamma-ray strip parametrization: the nature of the gamma-ray Active Galactic Nuclei of Uncertain type
• A Statistical Approach to Recognizing Source Classes for Unassociated Sources in the First Fermi-LAT Catalog
• Optically Selected BL Lacertae Candidates from the Sloan Digital Sky Survey Data Release Seven
• Infrared Colors of the gamma-ray detected blazars
• A simplified view of blazars: the gamma-ray case
• ESO-VLT optical spectroscopy of BL Lac objects: II. New redshifts, featureless objects and classification assessments
• Unveiling the nature of the unidentified gamma-ray sources I: a new method for the association of gamma-ray blazars
• ESO-VLT optical spectroscopy of BL Lac objects: I. new redshifts
• Optical spectroscopic observations of gamma-ray blazars candidates I: preliminary results
• The Lack of Torus Emission from BL Lacertae Objects: An Infrared View of Unification with WISE
• Unveiling the nature of the unidentified gamma-ray sources II: radio, infrared and optical counterparts of the gamma-ray blazar candidates
• Unveiling the nature of the unidentified gamma-ray sources III: gamma-ray blazar-like counterparts at low radio frequencies
• Unveiling the nature of the unidentified gamma-ray sources IV: the $\text{Swift}$ catalog of potential X-ray counterparts
• Unidentifed gamma-ray sources: hunting gamma-ray blazars
• Unveiling the nature of the unidentified gamma-ray sources V: analysis of the radio candidates with the kernel density estimation
• BL Lacertae identifications in a ROSAT-selected sample of Fermi unidentified objects
• The colours of BL Lac objects: a new approach to their classification
• Blazars spectral properties at 74 MHz
• Unveiling the nature of the unidentified gamma-ray sources VI: gamma-ray blazar candidates in the WISH survey and their radio properties
• ESO VLT Optical Spectroscopy of BL Lac Objects IV. New spectra and properties of the full sample
• Identification of New Gamma-Ray Blazar Candidates With Multifrequency Archival Observations
• 0FGL J1830.3+0617: A Fermi Blazar Near the Galactic Plane
• Searching for new gamma-ray blazar candidates in the 3rd Palermo BAT Hard X-ray Catalog with WISE

Cited by in corpus (46)

• Fermi Large Area Telescope Fourth Source Catalog
• The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• The WISE Blazar-Like Radio-Loud Sources: An All-Sky Catalog Of Candidate Gamma-Ray Blazars
• On the redshift of TeV BL Lac objects
• Two new catalogs of blazar candidates in the WISE infrared sky
• Radio detection prospects for a bulge population of millisecond pulsars as suggested by Fermi LAT observations of the inner Galaxy
• Optical spectroscopic observations of $\gamma$-ray blazar candidates VI. Further observations from TNG, WHT, OAN, SOAR and Magellan telescopes
• The Extragalactic Gamma-ray Sky in the Fermi era
• Optical Spectroscopic Observations of Gamma-ray Blazar Candidates. V. TNG, KPNO, and OAN Observations of Blazar Candidates of Uncertain Type in the Northern Hemisphere
• Optical spectroscopic observations of gamma-ray blazar candidates III. The 2013/2014 campaign in the Southern Hemisphere
• The Gamma-ray Blazar Quest: new optical spectra, state of art and future perspectives
• Refining the associations of the Fermi Large Area Telescope Source Catalogs
• Optical spectroscopic survey of a sample of Unidentified Fermi objects
• The Infrared-Gamma-Ray Connection: A WISE View of the Extragalactic Gamma-Ray Sky
• Optical spectroscopic survey of a sample of Unidentified Fermi objects: II
• Optical archival spectra of blazar candidates of uncertain type in the 3${}^{rd}$ Fermi Large Area Telescope Catalog
• Optical spectroscopic observations of gamma-ray blazar candidates VIII: the 2016-2017 follow up campaign carried out at SPM, NOT, KPNO and SOAR telescopes
• An optical overview of blazars with LAMOST I: Hunting changing-look blazars and new redshift estimates
• Radio Weak BL Lac objects in the Fermi era
• The Time-Domain Spectroscopic Survey: Target Selection for Repeat Spectroscopy
• Optical spectroscopic observations of gamma-ray blazar candidates. IX. Optical archival spectra and further observations from SOAR and OAGH
• Optical spectroscopic observations of gamma-ray blazar candidates. X. Results from the 2018--2019 SOAR and OAN-SPM observations of blazar candidates of uncertain type
• Identifying the 3FHL catalog: I. Results of the KOSMOS optical spectroscopy campaign
• Identifying the 3FHL catalog: CTIO results
• Optical characterization of WISE selected blazar candidates
• Optical spectroscopic observations of low-energy counterparts of Fermi-LAT gamma-ray sources
• Catalog of Long-Term Transient Sources in the First 10 Years of Fermi-LAT Data
• The physical properties of \textit{Fermi} TeV BL Lac objects jets
• New blazars from the cross-match of recent multi-frequency catalogs
• COMP2CAT: hunting compact double radio sources in the local Universe
• The spectra of IceCube Neutrino (SIN) candidate sources -- III. Optical spectroscopy and source characterization of the full sample
• ZBLLAC -- A spectroscopic database of BL Lacertae objects
• The $\gamma$-ray sky seen at X-ray energies I. Searching for the connection between X-rays and $\gamma$-rays in Fermi BL Lac objects
• The spectra of IceCube neutrino candidate sources -- I. Optical spectroscopy of blazars
• The $\gamma$-ray sky seen at X-ray energies II: the Swift hunt of Fermi BL Lac objects among unidentified gamma-ray sources
• Extended X-ray emission around FR II radio galaxies: hotspots, lobes and galaxy clusters
• Identifying the 3FHL catalog: V. Results of the CTIO-COSMOS optical spectroscopy campaign 2019
• Evaluating Optical Classification for {\em Fermi} Blazar Candidates with a Statistical method using Broadband Spectral Indices
• The fraction of BL Lac objects in groups of galaxies
• Powerful Radio Sources in the Southern Sky. I. Optical Identifications
• Hidden treasures in the unknown 3CR extragalactic radio sky: a multi-wavelength approach
• Identifying the 3FHL catalog: VI. Results of the 2019 Gemini optical spectroscopy campaign
• Optical monitoring in southern blazars. Analysis of variability and spectral colour behaviours
• An empirical "high-confidence" candidate zone for $Fermi$ BL Lacertae objects
• The SRG/eROSITA all-sky survey: Hard X-ray selected Active Galactic Nuclei
• A multifrequency characterization of the extragalactic hard X-ray sky