Optical spectroscopic survey of a sample of Unidentified Fermi objects: II

Abstract

We report on optical spectroscopy obtained at the 10.4m Gran Telescopio Canarias of 28 Fermi gamma-ray sources that completes the study of a sample of 60 targets of unidentified objects for which the detection of an X-ray and/or radio source inside the 3FGL error box is available. The observations are aimed to characterize the nature and measure the redshift of these sources. For all optical counterparts, the observations allow us to establish their AGN nature. In particular, we found 24 BL Lac objects, one QSO, one NLSy1 and two objects showing spectral features typical of Seyfert 2 galaxies. For most of them, we determine a spectroscopic redshift, while for five we can set lower limits based on the lack of stellar features from the host galaxy. The global properties of the full sample are briefly discussed.

26 pages, 3 figures, 4 tables; accepted for publication in ApJ

References in corpus (14)

• Active Galactic Nuclei: what's in a name?
• 3FHL: The Third Catalog of Hard Fermi-LAT Sources
• The Fermi blazar sequence
• ESO-VLT optical spectroscopy of BL Lac objects: II. New redshifts, featureless objects and classification assessments
• On the redshift of TeV BL Lac objects
• 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
• The Gamma-ray Blazar Quest: new optical spectra, state of art and future perspectives
• Optical spectroscopic survey of a sample of Unidentified Fermi objects
• Optical Spectroscopic Observations of Gamma-Ray Blazar Candidates. VII. Follow-up Campaign in the Southern Hemisphere
• High-energy sources at low radio frequency: the Murchison Widefield Array view of Fermi blazars
• Spectroscopy of 10 gamma-ray BL Lac objects at high redshift
• A new method to unveil blazars among multi-wavelength counterparts of Unassociated Fermi gamma-ray Sources

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