Identifying the 3FHL catalog: VI. Results of the 2019 Gemini optical spectroscopy campaign

Abstract

Active galactic Nuclei (AGNs) with their relativistic jets pointed toward the observer, are a class of luminous gamma-ray sources commonly known as blazars. The study of this source class is essential to unveil the physical processes powering these extreme jets, to understand their cosmic evolution, as well as to indirectly probe the extragalactic background light. To do so, however, one needs to correctly classify and measure a redshift for a large sample of these sources. The Third Fermi-LAT Catalog of High-Energy Sources (3FHL) contains $1212$ blazars detected at energies greater than 10 GeV. However, $\sim$25% of these sources are unclassified and $\sim$56% lack redshift information. To increase the optical completeness of blazars in the 3FHL catalog, we devised an optical spectroscopic follow-up campaign using 4 $m$ and 8 $m$ telescopes. In this paper, we present the results of the last part of this campaign, where we observed 5 blazars using the 8 $m$ Gemini-S telescope in Chile. We report all 5 sources to be classified as BL Lacs, a redshift lower limit for 2 sources, and featureless spectra for the remaining 3 sources. We also performed a one-zone leptonic fit to the two sources with the redshift lower limits.

arXiv comment10 pages, 3 Figures, 5 Tables, accepted for publication in The Astronomical Journal

References in corpus (44)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• Fermi Large Area Telescope Second Source Catalog
• Fermi Large Area Telescope First Source Catalog
• Neutrino emission from the direction of the blazar TXS 0506+056 prior to the IceCube-170922A alert
• Incremental Fermi Large Area Telescope Fourth Source Catalog
• Canonical high power blazars
• The power of blazar jets
• 3FHL: The Third Catalog of Hard Fermi-LAT Sources
• The Fermi blazar sequence
• The Cosmic Evolution of Fermi BL Lacertae Objects
• The Imprint of The Extragalactic Background Light in the Gamma-Ray Spectra of Blazars
• The Luminosity Function of Fermi-detected Flat-Spectrum Radio Quasars
• Spectroscopy of The Largest Ever Gamma-ray Selected BL Lac Sample
• Extreme synchrotron BL Lac objects
• Extreme TeV blazars and the intergalactic magnetic field
• A $\gamma$-ray determination of the Universe's star-formation history
• The relation between broad lines and gamma--ray luminosities in Fermi blazars
• Detection of the cosmic γ-ray horizon from multiwavelength observations of 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
• Optical spectroscopic observations of blazars and gamma-ray blazar candidates in the Sloan Digital Sky Survey Data Release Nine
• 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
• A GeV-TeV Measurement of the Extragalactic Background Light
• Blue Fermi Flat Spectrum Radio Quasars
• The Gamma-ray Blazar Quest: new optical spectra, state of art and future perspectives
• Optical spectroscopic observations of gamma-ray blazar candidates IV. Results of the 2014 follow-up campaign
• Optical spectroscopic survey of a sample of Unidentified Fermi objects
• BeppoSAX Observations of Synchrotron X-ray Emission from Radio Quasars
• Optical spectroscopy of Blazars for the Cherenkov Telescope Array
• Discrete Knot Ejection from the Jet in a Nearby Low Luminosity Active Galactic Nucleus, M81*
• Optical spectroscopic observations of gamma-ray blazar candidates. IX. Optical archival spectra and further observations from SOAR and OAGH
• Looking for blazars in a sample of unidentified high-energy emitting Fermi sources
• 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
• Hunting extreme BL Lacertae blazars with Fermi-LAT
• HESS J1943+213: An Extreme Blazar Shining Through The Galactic Plane
• Identifying the 3FHL catalog: I. Archival Swift Observations and Source Classification
• Identifying the 3FHL catalog: V. Results of the CTIO-COSMOS optical spectroscopy campaign 2019
• Identifying the 3FHL Catalog. VI. Swift Observations of 3FHL Unassociated Objects with Source Classification via Machine Learning
• Identifying the 3FHL Catalog. IV. Swift Observations of Unassociated Fermi-LAT 3FHL Sources