Optical spectroscopic characterization of Fermi blazar candidates of uncertain type with TNG and DOT: First Results

Abstract

The classification of gamma-ray-detected blazar candidates of uncertain type (BCU) is a relevant problem in extragalactic gamma-ray astronomy. Here we report the optical spectroscopic characterization, using two 3-4~m class telescopes, Telescopio Nazionale Galileo and Devasthal Optical Telescope, of 27 BCUs detected with the Fermi Large Area Telescope. Since the identification of emission lines is easier in broad-line blazars, which usually exhibit low frequency peaked (synchrotron peak frequency $⩽10^{14}$ Hz) spectral energy distribution, we primarily target such BCUs. We found that 8 out of 27 sources exhibit broad emission lines in their optical spectra, 3 of them have redshifts $>$1 and the farthest one is at $z=2.55$. The optical spectra of 2 of the 19 remaining objects are dominated by the absorption spectra of the host galaxy, and there is a tentative detection of the Lyman-$\alpha$ absorption feature in one source. The spectra of the remaining 16 objects, on the other hand, are found to be featureless.

arXiv commentMNRAS, in press

References in corpus (38)

• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Cosmic-Ray Rejection by Laplacian Edge Detection
• Fermi Large Area Telescope Fourth Source Catalog
• The Second Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release
• The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• The Luminosity Function of Fermi-detected Flat-Spectrum Radio Quasars
• A $\gamma$-ray determination of the Universe's star-formation history
• An observational determination of the evolving extragalactic background light from the multiwavelength HST/CANDELS survey in the Fermi and CTA era
• The WISE gamma-ray strip parametrization: the nature of the gamma-ray Active Galactic Nuclei of Uncertain type
• The Central Engines of Fermi Blazars
• A new measurement of the Hubble constant and matter content of the Universe using extragalactic background light $\gamma$-ray attenuation
• General Physical Properties of CGRaBS Blazars
• Optical spectroscopic observations of gamma-ray blazars candidates I: preliminary results
• Optical spectroscopic observations of $\gamma$-ray blazar candidates VI. Further observations from TNG, WHT, OAN, SOAR and Magellan telescopes
• Active Galactic Nuclei under the scrutiny of CTA
• Optical spectroscopic observations of gamma-ray blazar candidates II. The 2013 KPNO campaign in the Northern Hemisphere
• Optical spectroscopic observations of gamma-ray blazar candidates III. The 2013/2014 campaign in the Southern Hemisphere
• A GeV-TeV Measurement of the Extragalactic Background Light
• Search for gamma-ray-emitting active galactic nuclei in the Fermi-LAT unassociated sample using machine learning
• Optical spectroscopic survey of a sample of Unidentified Fermi objects
• Evaluating the optical classification of Fermi BCUs using machine learning
• Blazars at the Cosmic Dawn
• Optical spectroscopic survey of a sample of Unidentified Fermi objects: II
• Optical spectroscopic observations of gamma-ray blazar candidates VIII: the 2016-2017 follow up campaign carried out at SPM, NOT, KPNO and SOAR telescopes
• Radio Weak BL Lac objects in the Fermi era
• Multi-Frequency Observations of the Candidate Neutrino Emitting Blazar BZB J0955+3551
• Optical spectroscopic observations of gamma-ray blazar candidates. IX. Optical archival spectra and further observations from SOAR and OAGH
• Identifying the 3FHL catalog: CTIO results
• Identifying the 3FHL catalog: I. Results of the KOSMOS optical spectroscopy campaign
• Classification of Blazar Candidates of Uncertain Type from the Fermi LAT 8-Year Source Catalog with an Artificial Neural Network
• The First Gamma-ray Emitting BL Lacertae Object at the Cosmic Dawn
• Hunting extreme BL Lacertae blazars with Fermi-LAT
• Application of the MST clustering to the high energy gamma-ray sky. I - New possible detection of high-energy gamma-ray emission associated with BL Lac objects
• Very high-energy constraints on the Infrared Extragalactic Background Light
• A new flaring high energy gamma-ray source
• Optical spectroscopic classification of a selection of Southern Hemisphere Fermi-LAT unclassified blazars
• Identifying the 3FHL catalog: V. Results of the CTIO-COSMOS optical spectroscopy campaign 2019

Cited by in corpus (2)

• Radio and mid-infrared properties of the blazar J1419$-$0838
• Zooming into the neutrino-associated blazar candidate J1718+4239