The First Gamma-ray Emitting BL Lacertae Object at the Cosmic Dawn

Abstract

One of the major challenges in studying the cosmic evolution of relativistic jets is the identification of the high-redshift ($z>3$) BL Lacertae objects, a class of jetted active galactic nuclei characterized by their quasi-featureless optical spectra. Here we report the identification of the first $\gamma$-ray emitting BL Lac object, 4FGL~J1219.0+3653 (J1219), beyond $z=3$, i.e., within the first two billion years of the age of the Universe. The optical and near-infrared spectra of J1219 taken from 10.4 m Gran Telescopio Canarias exhibit no emission lines down to an equivalent width of $\sim$3.5 A supporting its BL Lac nature. The detection of a strong Lyman-$\alpha$ break at $\sim$5570 A, on the other hand, confirms that J2119 is indeed a high-redshift ($z\sim 3.59$) quasar. Based on the prediction of a recent BL Lac evolution model, J1219 is one of the only two such objects expected to be present within the comoving volume at $z=3.5$. Future identifications of more $z>3$ $\gamma$-ray emitting BL Lac sources, therefore, will be crucial to verify the theories of their cosmic evolution.

arXiv commentAccepted for publication in The Astrophysical Journal Letters

References in corpus (27)

• Planck 2015 results. XIII. Cosmological parameters
• Correcting for the Effects of Interstellar Extinction
• The Sixteenth Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra
• A Unifying View of the Spectral Energy Distributions of Blazars
• Extragalactic Background Light Inferred from AEGIS Galaxy SED-type Fractions
• The Third Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
• The transition between BL Lac objects and Flat Spectrum Radio Quasars
• A simplified view of blazars: clearing the fog around long-standing selection effects
• The Fermi blazar sequence
• The Cosmic Evolution of Fermi BL Lacertae Objects
• Spectroscopy of Broad Line Blazars from 1LAC
• A $\gamma$-ray determination of the Universe's star-formation history
• Identification of the infrared non-thermal emission in Blazars
• A Direct Measurement of the IGM Opacity to HI Ionizing Photons
• An unbiased measurement of the UV background and its evolution via the proximity effect in quasar spectra
• BL Lacertae objects beyond redshift 1.3 - UV-to-NIR photometry and photometric redshift for Fermi/LAT blazars
• ESO-VLT optical spectroscopy of BL Lac objects: I. new redshifts
• Gamma-ray Blazars Within the First 2 Billion Years
• Spectral analysis of Fermi-LAT blazars above 50 GeV
• A multiwavelength approach to the SFR estimation in galaxies at intermediate redshifts
• Blazars at the Cosmic Dawn
• Spectroscopy of 10 gamma-ray BL Lac objects at high redshift
• Dynamical Black Hole Masses of BL Lac Objects from the Sloan Digital Sky Survey
• High redshift BL Lac objects: spectroscopy of candidates
• Data boundary fitting using a generalised least-squares method
• Optical spectroscopy of SDSS J004054.65-0915268: three possible scenarios for the classification. A z \sim 5 BL Lacertae, blue FSRQ or a weak emission line quasar

Cited by in corpus (9)

• The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope -- Data Release 3
• The Central Engines of Fermi Blazars
• The Physical Properties of Changing-look Blazars
• Using Neural Networks to Differentiate Newly Discovered BL Lacs and FSRQs among the 4FGL Unassociated Sources Employing Gamma-ray, X-ray, UV/Optical and IR Data
• Identifying the 3FHL catalog: V. Results of the CTIO-COSMOS optical spectroscopy campaign 2019
• The Impact of the CMB on the Evolution of high-z Blazars
• Optical spectroscopic characterization of Fermi blazar candidates of uncertain type with TNG and DOT: First Results
• Comprehensive view on a $z\sim 6.5$ radio-loud QSO: from the radio to the optical/NIR to the X-ray band
• Central Engine and Spectral Energy Distribution Properties of High Redshift Gamma Ray Blazars