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Title: The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope

Abstract

We report the fourth catalog of active galactic nuclei (AGNs) detected by the Fermi Gamma-ray Space Telescope Large Area Telescope (4LAC) between 2008 August 4 and 2016 August 2 contains objects located at high Galactic latitudes (). It includes 85% more sources than the previous 3LAC catalog based on 4 yr of data. AGNs represent at least 79% of the high-latitude sources in the fourth Fermi-Large Area Telescope Source Catalog (4FGL), which covers the energy range from 50 MeV to 1 TeV. In addition, gamma-ray AGNs are found at low Galactic latitudes. Most of the 4LAC AGNs are blazars (98%), while the remainder are other types of AGNs. The blazar population consists of 24% Flat Spectrum Radio Quasars (FSRQs), 38% BL Lac-type objects, and 38% blazar candidates of unknown types (BCUs). On average, FSRQs display softer spectra and stronger variability in the gamma-ray band than BL Lacs do, confirming previous findings. All AGNs detected by ground-based atmospheric Cerenkov telescopes are also found in the 4LAC.

Authors:
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Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE; National Aeronautics and Space Administration (NASA); National Science Foundation (NSF); Alfred P. Sloan Foundation
Contributing Org.:
Fermi LAT Collaboration
OSTI Identifier:
1616843
Grant/Contract Number:  
AC02-76SF00515
Resource Type:
Accepted Manuscript
Journal Name:
The Astrophysical Journal (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 892; Journal Issue: 2; Journal ID: ISSN 1538-4357
Publisher:
Institute of Physics (IOP)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; Active galactic nuclei; Blazars; Gamma-ray sources; Relativistic jets; Quasars; BL Lacertae objects

Citation Formats

Ajello, M., Angioni, R., Axelsson, M., Ballet, J., Barbiellini, G., Bastieri, D., Becerra Gonzalez, J., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bottacini, E., Bruel, P., Buson, S., Cafardo, F., Cameron, R. A., Cavazzuti, E., Chen, S., Cheung, C. C., Ciprini, S., Costantin, D., Cutini, S., D’Ammando, F., de la Torre Luque, P., de Menezes, R., de Palma, F., Desai, A., Di Lalla, N., Di Venere, L., Domínguez, A., Dirirsa, F. Fana, Ferrara, E. C., Finke, J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Garrappa, S., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guiriec, S., Harita, S., Hays, E., Horan, D., Itoh, R., Jóhannesson, G., Kovac’evic’, M., Krauss, F., Kreter, M., Kuss, M., Larsson, S., Leto, C., Li, J., Liodakis, I., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Maldera, S., Manfreda, A., Martí-Devesa, G., Massaro, F., Mazziotta, M. N., Mereu, I., Meyer, M., Migliori, G., Mirabal, N., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nemmen, R., Nuss, E., Ojha, L. S., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paliya, V. S., Pei, Z., Peña-Herazo, H., Persic, M., Pesce-Rollins, M., Petrov, L., Piron, F., Poon, H., Principe, G., Rainò, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Schinzel, F. K., Serini, D., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tachibana, Y., Thompson, D. J., Torres, D. F., Torresi, E., Troja, E., Valverde, J., van Zyl, P., and Yassine, M. The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope. United States: N. p., 2020. Web. doi:10.3847/1538-4357/ab791e.
Ajello, M., Angioni, R., Axelsson, M., Ballet, J., Barbiellini, G., Bastieri, D., Becerra Gonzalez, J., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bottacini, E., Bruel, P., Buson, S., Cafardo, F., Cameron, R. A., Cavazzuti, E., Chen, S., Cheung, C. C., Ciprini, S., Costantin, D., Cutini, S., D’Ammando, F., de la Torre Luque, P., de Menezes, R., de Palma, F., Desai, A., Di Lalla, N., Di Venere, L., Domínguez, A., Dirirsa, F. Fana, Ferrara, E. C., Finke, J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Garrappa, S., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guiriec, S., Harita, S., Hays, E., Horan, D., Itoh, R., Jóhannesson, G., Kovac’evic’, M., Krauss, F., Kreter, M., Kuss, M., Larsson, S., Leto, C., Li, J., Liodakis, I., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Maldera, S., Manfreda, A., Martí-Devesa, G., Massaro, F., Mazziotta, M. N., Mereu, I., Meyer, M., Migliori, G., Mirabal, N., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nemmen, R., Nuss, E., Ojha, L. S., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paliya, V. S., Pei, Z., Peña-Herazo, H., Persic, M., Pesce-Rollins, M., Petrov, L., Piron, F., Poon, H., Principe, G., Rainò, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Schinzel, F. K., Serini, D., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tachibana, Y., Thompson, D. J., Torres, D. F., Torresi, E., Troja, E., Valverde, J., van Zyl, P., & Yassine, M. The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope. United States. doi:https://doi.org/10.3847/1538-4357/ab791e
Ajello, M., Angioni, R., Axelsson, M., Ballet, J., Barbiellini, G., Bastieri, D., Becerra Gonzalez, J., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bottacini, E., Bruel, P., Buson, S., Cafardo, F., Cameron, R. A., Cavazzuti, E., Chen, S., Cheung, C. C., Ciprini, S., Costantin, D., Cutini, S., D’Ammando, F., de la Torre Luque, P., de Menezes, R., de Palma, F., Desai, A., Di Lalla, N., Di Venere, L., Domínguez, A., Dirirsa, F. Fana, Ferrara, E. C., Finke, J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Garrappa, S., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guiriec, S., Harita, S., Hays, E., Horan, D., Itoh, R., Jóhannesson, G., Kovac’evic’, M., Krauss, F., Kreter, M., Kuss, M., Larsson, S., Leto, C., Li, J., Liodakis, I., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Maldera, S., Manfreda, A., Martí-Devesa, G., Massaro, F., Mazziotta, M. N., Mereu, I., Meyer, M., Migliori, G., Mirabal, N., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nemmen, R., Nuss, E., Ojha, L. S., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paliya, V. S., Pei, Z., Peña-Herazo, H., Persic, M., Pesce-Rollins, M., Petrov, L., Piron, F., Poon, H., Principe, G., Rainò, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Schinzel, F. K., Serini, D., Sgrò, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tachibana, Y., Thompson, D. J., Torres, D. F., Torresi, E., Troja, E., Valverde, J., van Zyl, P., and Yassine, M. Thu . "The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope". United States. doi:https://doi.org/10.3847/1538-4357/ab791e. https://www.osti.gov/servlets/purl/1616843.
@article{osti_1616843,
title = {The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope},
author = {Ajello, M. and Angioni, R. and Axelsson, M. and Ballet, J. and Barbiellini, G. and Bastieri, D. and Becerra Gonzalez, J. and Bellazzini, R. and Bissaldi, E. and Bloom, E. D. and Bonino, R. and Bottacini, E. and Bruel, P. and Buson, S. and Cafardo, F. and Cameron, R. A. and Cavazzuti, E. and Chen, S. and Cheung, C. C. and Ciprini, S. and Costantin, D. and Cutini, S. and D’Ammando, F. and de la Torre Luque, P. and de Menezes, R. and de Palma, F. and Desai, A. and Di Lalla, N. and Di Venere, L. and Domínguez, A. and Dirirsa, F. Fana and Ferrara, E. C. and Finke, J. and Franckowiak, A. and Fukazawa, Y. and Funk, S. and Fusco, P. and Gargano, F. and Garrappa, S. and Gasparrini, D. and Giglietto, N. and Giordano, F. and Giroletti, M. and Green, D. and Grenier, I. A. and Guiriec, S. and Harita, S. and Hays, E. and Horan, D. and Itoh, R. and Jóhannesson, G. and Kovac’evic’, M. and Krauss, F. and Kreter, M. and Kuss, M. and Larsson, S. and Leto, C. and Li, J. and Liodakis, I. and Longo, F. and Loparco, F. and Lott, B. and Lovellette, M. N. and Lubrano, P. and Madejski, G. M. and Maldera, S. and Manfreda, A. and Martí-Devesa, G. and Massaro, F. and Mazziotta, M. N. and Mereu, I. and Meyer, M. and Migliori, G. and Mirabal, N. and Mizuno, T. and Monzani, M. E. and Morselli, A. and Moskalenko, I. V. and Negro, M. and Nemmen, R. and Nuss, E. and Ojha, L. S. and Ojha, R. and Omodei, N. and Orienti, M. and Orlando, E. and Ormes, J. F. and Paliya, V. S. and Pei, Z. and Peña-Herazo, H. and Persic, M. and Pesce-Rollins, M. and Petrov, L. and Piron, F. and Poon, H. and Principe, G. and Rainò, S. and Rando, R. and Rani, B. and Razzano, M. and Razzaque, S. and Reimer, A. and Reimer, O. and Schinzel, F. K. and Serini, D. and Sgrò, C. and Siskind, E. J. and Spandre, G. and Spinelli, P. and Suson, D. J. and Tachibana, Y. and Thompson, D. J. and Torres, D. F. and Torresi, E. and Troja, E. and Valverde, J. and van Zyl, P. and Yassine, M.},
abstractNote = {We report the fourth catalog of active galactic nuclei (AGNs) detected by the Fermi Gamma-ray Space Telescope Large Area Telescope (4LAC) between 2008 August 4 and 2016 August 2 contains objects located at high Galactic latitudes (). It includes 85% more sources than the previous 3LAC catalog based on 4 yr of data. AGNs represent at least 79% of the high-latitude sources in the fourth Fermi-Large Area Telescope Source Catalog (4FGL), which covers the energy range from 50 MeV to 1 TeV. In addition, gamma-ray AGNs are found at low Galactic latitudes. Most of the 4LAC AGNs are blazars (98%), while the remainder are other types of AGNs. The blazar population consists of 24% Flat Spectrum Radio Quasars (FSRQs), 38% BL Lac-type objects, and 38% blazar candidates of unknown types (BCUs). On average, FSRQs display softer spectra and stronger variability in the gamma-ray band than BL Lacs do, confirming previous findings. All AGNs detected by ground-based atmospheric Cerenkov telescopes are also found in the 4LAC.},
doi = {10.3847/1538-4357/ab791e},
journal = {The Astrophysical Journal (Online)},
number = 2,
volume = 892,
place = {United States},
year = {2020},
month = {4}
}

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Works referenced in this record:

Semi-analytic modelling of the extragalactic background light and consequences for extragalactic gamma-ray spectra: Modelling of the EBL and gamma-ray spectra
journal, April 2012

  • Gilmore, Rudy C.; Somerville, Rachel S.; Primack, Joel R.
  • Monthly Notices of the Royal Astronomical Society, Vol. 422, Issue 4
  • DOI: 10.1111/j.1365-2966.2012.20841.x

FERMI LARGE AREA TELESCOPE THIRD SOURCE CATALOG
journal, June 2015

  • Acero, F.; Ackermann, M.; Ajello, M.
  • The Astrophysical Journal Supplement Series, Vol. 218, Issue 2
  • DOI: 10.1088/0067-0049/218/2/23

Restarting activity in the nucleus of PBC J2333.9-2343: An extreme case of jet realignment
journal, July 2017


Optical Spectroscopic Observations of Blazars and γ-Ray Blazar Candidates in the Sloan Digital sky Survey data Release nine
journal, September 2014


An Intense Gamma‐Ray Flare of PKS 1622−297
journal, February 1997

  • Mattox, J. R.; Wagner, S. J.; Malkan, M.
  • The Astrophysical Journal, Vol. 476, Issue 2
  • DOI: 10.1086/303639

THE LUMINOSITY FUNCTION OF FERMI -DETECTED FLAT-SPECTRUM RADIO QUASARS
journal, May 2012


High-redshift BL Lac Objects: Spectroscopy of Candidates
journal, July 2018


FRII CAT : A FIRST catalog of FR II radio galaxies
journal, May 2017


Deriving the Contribution of Blazars to the Fermi -LAT Extragalactic γ -ray Background at E > 10 GeV with Efficiency Corrections and Photon Statistics
journal, March 2018


Extreme blazars as counterparts of IceCube astrophysical neutrinos
journal, January 2016

  • Padovani, P.; Resconi, E.; Giommi, P.
  • Monthly Notices of the Royal Astronomical Society, Vol. 457, Issue 4
  • DOI: 10.1093/mnras/stw228

FERMI LARGE AREA TELESCOPE FIRST SOURCE CATALOG
journal, May 2010

  • Abdo, A. A.; Ackermann, M.; Ajello, M.
  • The Astrophysical Journal Supplement Series, Vol. 188, Issue 2
  • DOI: 10.1088/0067-0049/188/2/405

A deep search for 21-cm absorption in high redshift damped Lyman- α systems
journal, February 2003


OPTICAL SPECTROSCOPIC OBSERVATIONS OF γ -RAY BLAZAR CANDIDATES. III. THE 2013/2014 CAMPAIGN IN THE SOUTHERN HEMISPHERE
journal, April 2015


Planck 2013 results. XVI. Cosmological parameters
journal, October 2014


Optical Spectroscopic Observations of Gamma-Ray Blazar Candidates. iv. Results of the 2014 Follow-Up Campaign
journal, April 2015


Chandra observations of gamma-ray emitting radio galaxies
journal, July 2018

  • Zargaryan, D.; Sahakyan, N.; Harutyunian, H.
  • International Journal of Modern Physics D, Vol. 27, Issue 10
  • DOI: 10.1142/S0218271818440224

CRATES: An All‐Sky Survey of Flat‐Spectrum Radio Sources
journal, July 2007

  • Healey, Stephen E.; Romani, Roger W.; Taylor, Gregory B.
  • The Astrophysical Journal Supplement Series, Vol. 171, Issue 1
  • DOI: 10.1086/513742

Optical identifications of Parkes radio sources using UK Schmidt plates
journal, September 1983

  • Prestage, R. M.; Peacock, J. A.
  • Monthly Notices of the Royal Astronomical Society, Vol. 204, Issue 2
  • DOI: 10.1093/mnras/204.2.355

CGRaBS: An All‐Sky Survey of Gamma‐Ray Blazar Candidates
journal, March 2008

  • Healey, Stephen E.; Romani, Roger W.; Cotter, Garret
  • The Astrophysical Journal Supplement Series, Vol. 175, Issue 1
  • DOI: 10.1086/523302

Modeling the emission processes in blazars
journal, April 2007


The first γ-ray detection of the narrow-line Seyfert 1 FBQS J1644+2619
journal, July 2015

  • D'Ammando, F.; Orienti, M.; Larsson, J.
  • Monthly Notices of the Royal Astronomical Society, Vol. 452, Issue 1
  • DOI: 10.1093/mnras/stv1278

Optical archival spectra of blazar candidates of uncertain type in the 3rd Fermi Large Area Telescope Catalog
journal, August 2016

  • Álvarez Crespo, N.; Massaro, F.; D’Abrusco, R.
  • Astrophysics and Space Science, Vol. 361, Issue 9
  • DOI: 10.1007/s10509-016-2902-1

Spectropolarimetry of 'narrow-line' Seyfert 1 galaxies
journal, July 1989

  • Goodrich, Robert W.
  • The Astrophysical Journal, Vol. 342
  • DOI: 10.1086/167586

FERMI LARGE AREA TELESCOPE DETECTION OF EXTENDED GAMMA-RAY EMISSION FROM THE RADIO GALAXY FORNAX A
journal, July 2016


Superluminal motion in a compact steep spectrum radio source 3C 138
journal, April 2001


Modeling the Extragalactic Background Light from Stars and dust
journal, February 2010


Optical Spectroscopic Observations of Gamma-Ray Blazar Candidates. vi. Further Observations from tng, wht, oan, Soar, and Magellan Telescopes
journal, March 2016


Systematic Study of Gamma-Ray-Bright Blazars with Optical Polarization and Gamma-Ray Variability
journal, December 2016

  • Itoh, Ryosuke; Nalewajko, Krzysztof; Fukazawa, Yasushi
  • The Astrophysical Journal, Vol. 833, Issue 1
  • DOI: 10.3847/1538-4357/833/1/77

2WHSP: A multi-frequency selected catalogue of high energy and very high energy γ -ray blazars and blazar candidates
journal, January 2017


THE WISE BLAZAR-LIKE RADIO-LOUD SOURCES: AN ALL-SKY CATALOG OF CANDIDATE γ-RAY BLAZARS
journal, October 2014

  • D'Abrusco, R.; Massaro, F.; Paggi, A.
  • The Astrophysical Journal Supplement Series, Vol. 215, Issue 1
  • DOI: 10.1088/0067-0049/215/1/14

The blazar sequence: validity and predictions
journal, April 2007


The extragalactic gamma-ray sky in the Fermi era
journal, December 2015

  • Massaro, Francesco; Thompson, David J.; Ferrara, Elizabeth C.
  • The Astronomy and Astrophysics Review, Vol. 24, Issue 1
  • DOI: 10.1007/s00159-015-0090-6

An Updated Catalog of Giant Radio Sources
journal, September 2018

  • Kuźmicz, Agnieszka; Jamrozy, Marek; Bronarska, Katarzyna
  • The Astrophysical Journal Supplement Series, Vol. 238, Issue 1
  • DOI: 10.3847/1538-4365/aad9ff

Extragalactic background light inferred from AEGIS galaxy-SED-type fractions: EBL from AEGIS galaxy-SED-type fractions
journal, October 2010


Radio and gamma-ray properties of extragalactic jets from the TANAMI sample
journal, May 2016


The Second LBA Calibrator Survey of southern compact extragalactic radio sources – LCS2
journal, January 2019

  • Petrov, Leonid; de Witt, Alet; Sadler, Elaine M.
  • Monthly Notices of the Royal Astronomical Society, Vol. 485, Issue 1
  • DOI: 10.1093/mnras/stz242

FILLING IN THE GAPS IN THE 4.85 GHz SKY
journal, August 2009


The 6dF Galaxy Survey: final redshift release (DR3) and southern large-scale structures
journal, October 2009


Gamma-Ray-emitting Narrow-line Seyfert 1 Galaxies in the Sloan Digital Sky Survey
journal, January 2018

  • Paliya, Vaidehi S.; Ajello, M.; Rakshit, S.
  • The Astrophysical Journal, Vol. 853, Issue 1
  • DOI: 10.3847/2041-8213/aaa5ab

γ-Ray and Parsec-Scale jet Properties of a Complete Sample of Blazars from the Mojave Program
journal, November 2011


Parameter estimation in astronomy through application of the likelihood ratio
journal, March 1979


Exploring the connection between radio and GeV-TeV γ -ray emission in the 1FHL and 2FHL AGN samples
journal, October 2017


SUMSS: a wide-field radio imaging survey of the southern sky - II. The source catalogue
journal, July 2003


The Parkes-MIT-NRAO (PMN) surveys. I - The 4850 MHz surveys and data reduction
journal, May 1993

  • Griffith, Mark R.; Wright, Alan E.
  • The Astronomical Journal, Vol. 105
  • DOI: 10.1086/116545

REFINING THE ASSOCIATIONS OF THE FERMI LARGE AREA TELESCOPE SOURCE CATALOGS
journal, February 2015

  • Massaro, F.; D’Abrusco, R.; Landoni, M.
  • The Astrophysical Journal Supplement Series, Vol. 217, Issue 1
  • DOI: 10.1088/0067-0049/217/1/2

The Search for Spatial Extension in High-latitude Sources Detected by the Fermi Large Area Telescope
journal, August 2018

  • Ackermann, M.; Ajello, M.; Baldini, L.
  • The Astrophysical Journal Supplement Series, Vol. 237, Issue 2
  • DOI: 10.3847/1538-4365/aacdf7

New Associations of Gamma-Ray Sources from the Fermi Second Source Catalog
journal, February 2015

  • Schinzel, Frank K.; Petrov, Leonid; Taylor, Gregory B.
  • The Astrophysical Journal Supplement Series, Vol. 217, Issue 1
  • DOI: 10.1088/0067-0049/217/1/4

Gamma-Ray Blazars within the First 2 Billion Years
journal, February 2017


Optical spectroscopic observations of gamma-ray blazar candidates VIII: the 2016–2017 follow up campaign carried out at SPM, NOT, KPNO and SOAR telescopes
journal, January 2019

  • Marchesini, E. J.; Peña-Herazo, H. A.; Álvarez Crespo, N.
  • Astrophysics and Space Science, Vol. 364, Issue 1
  • DOI: 10.1007/s10509-018-3490-z

Radio Follow-up on All Unassociated Gamma-Ray Sources from the Third Fermi Large Area Telescope Source Catalog
journal, April 2017

  • Schinzel, Frank K.; Petrov, Leonid; Taylor, Gregory B.
  • The Astrophysical Journal, Vol. 838, Issue 2
  • DOI: 10.3847/1538-4357/aa6439

FIRST DETECTION IN GAMMA-RAYS OF A YOUNG RADIO GALAXY: FERMI -LAT OBSERVATIONS OF THE COMPACT SYMMETRIC OBJECT PKS 1718−649
journal, April 2016


Parent population of flat-spectrum radio-loud narrow-line Seyfert 1 galaxies
journal, May 2015


THE SPECTRAL ENERGY DISTRIBUTION OF FERMI BRIGHT BLAZARS
journal, May 2010


Optical spectroscopic observations of γ -ray blazar candidates: II. The 2013 KPNO campaign in the northern hemisphere
journal, March 2015


The CLASS blazar survey — II. Optical properties
journal, February 2002


Fermi Large Area Telescope Fourth Source Catalog
journal, March 2020

  • Abdollahi, S.; Acero, F.; Ackermann, M.
  • The Astrophysical Journal Supplement Series, Vol. 247, Issue 1
  • DOI: 10.3847/1538-4365/ab6bcb

A Catalog of Narrow Line Seyfert 1 Galaxies from the Sloan Digital Sky Survey Data Release 12
journal, April 2017

  • Rakshit, Suvendu; Stalin, C. S.; Chand, Hum
  • The Astrophysical Journal Supplement Series, Vol. 229, Issue 2
  • DOI: 10.3847/1538-4365/aa6971

Australia Telescope Compact Array observations of Fermi unassociated sources
journal, April 2013

  • Petrov, Leonid; Mahony, Elizabeth K.; Edwards, Philip G.
  • Monthly Notices of the Royal Astronomical Society, Vol. 432, Issue 2
  • DOI: 10.1093/mnras/stt550

Optical spectroscopic observations of gamma-ray blazar candidates. VII. Follow-up campaign in the southern hemisphere
journal, November 2017

  • Peña-Herazo, H. A.; Marchesini, E. J.; Álvarez Crespo, N.
  • Astrophysics and Space Science, Vol. 362, Issue 12
  • DOI: 10.1007/s10509-017-3208-7

Second ROSAT all-sky survey (2RXS) source catalogue
journal, March 2016


Identifying the 3FHL Catalog. II. Results of the KOSMOS Optical Spectroscopy Campaign
journal, October 2018


Spectroscopy of 10 γ -Ray BL Lac Objects at High Redshift
journal, July 2017

  • Paiano, Simona; Landoni, Marco; Falomo, Renato
  • The Astrophysical Journal, Vol. 844, Issue 2
  • DOI: 10.3847/1538-4357/aa7aac

Spectroscopy of the Largest ever γ-Ray-Selected bl lac Sample
journal, January 2013


THE SECOND CATALOG OF ACTIVE GALACTIC NUCLEI DETECTED BY THE FERMI LARGE AREA TELESCOPE
journal, December 2011


Blazar flaring patterns (B-FlaP) classifying blazar candidate of uncertain type in the third Fermi -LAT catalogue by artificial neural networks
journal, July 2016

  • Chiaro, G.; Salvetti, D.; La Mura, G.
  • Monthly Notices of the Royal Astronomical Society, Vol. 462, Issue 3
  • DOI: 10.1093/mnras/stw1830

Investigation of Two Fermi -LAT Gamma-Ray Blazars Coincident with High-energy Neutrinos Detected by IceCube
journal, July 2019


THE THIRD CATALOG OF ACTIVE GALACTIC NUCLEI DETECTED BY THE FERMI LARGE AREA TELESCOPE
journal, August 2015


Near-Equipartition jets with Log-Parabola Electron Energy Distribution and the Blazar Spectral-Index Diagrams
journal, August 2015


Optical Spectroscopic Survey of a Sample of Unidentified Fermi Objects
journal, December 2017

  • Paiano, Simona; Falomo, Renato; Franceschini, Alberto
  • The Astrophysical Journal, Vol. 851, Issue 2
  • DOI: 10.3847/1538-4357/aa9af4

The NRAO VLA Sky Survey
journal, May 1998

  • Condon, J. J.; Cotton, W. D.; Greisen, E. W.
  • The Astronomical Journal, Vol. 115, Issue 5
  • DOI: 10.1086/300337

PHOTOMETRICALLY TRIGGERED KECK SPECTROSCOPY OF FERMI BL LACERTAE OBJECTS
journal, October 2013

  • Shaw, Michael S.; Filippenko, Alexei V.; Romani, Roger W.
  • The Astronomical Journal, Vol. 146, Issue 5
  • DOI: 10.1088/0004-6256/146/5/127

FERMI LARGE AREA TELESCOPE OBSERVATIONS OF MISALIGNED ACTIVE GALACTIC NUCLEI
journal, August 2010


General Physical Properties of CGRaBS Blazars
journal, December 2017

  • Paliya, Vaidehi S.; Marcotulli, L.; Ajello, M.
  • The Astrophysical Journal, Vol. 851, Issue 1
  • DOI: 10.3847/1538-4357/aa98e1

Discovery of Twin Relativistic Jets in the Nearby E/S0 Galaxy NGC 3894
journal, May 1998

  • Taylor, G. B.; Wrobel, J. M.; Vermeulen, R. C.
  • The Astrophysical Journal, Vol. 498, Issue 2
  • DOI: 10.1086/305586

The Fermi blazar sequence
journal, April 2017

  • Ghisellini, G.; Righi, C.; Costamante, L.
  • Monthly Notices of the Royal Astronomical Society, Vol. 469, Issue 1
  • DOI: 10.1093/mnras/stx806

On the likelihood ratio for source identification
journal, December 1992

  • Sutherland, W.; Saunders, W.
  • Monthly Notices of the Royal Astronomical Society, Vol. 259, Issue 3
  • DOI: 10.1093/mnras/259.3.413

Unveiling the nature of the γ-ray emitting active galactic nucleus PKS 0521−36
journal, May 2015

  • D'Ammando, F.; Orienti, M.; Tavecchio, F.
  • Monthly Notices of the Royal Astronomical Society, Vol. 450, Issue 4
  • DOI: 10.1093/mnras/stv909

FRI CAT : A FIRST catalog of FR I radio galaxies
journal, January 2017


Narrow-line Seyfert 1s: 15 years later
journal, September 2000


Optical Spectroscopic Observations of γ-Ray Blazar Candidates. i. Preliminary Results
journal, April 2014


RADIO-WEAK BL LAC OBJECTS IN THE FERMI ERA
journal, January 2017


The Radio/Gamma Connection of Blazars from High to Low Radio Frequencies
journal, December 2018


Optical Spectroscopic Survey of a Sample of Unidentified Fermi Objects: II
journal, January 2019

  • Paiano, Simona; Falomo, Renato; Treves, Aldo
  • The Astrophysical Journal, Vol. 871, Issue 2
  • DOI: 10.3847/1538-4357/aaf6e4

The sequence of Compton dominance in blazars based on data from WISE and Fermi -LAT
journal, October 2017


The Australia Telescope 20 GHz Survey: the source catalogue
journal, March 2010


Missing Gamma-Ray Halos and the Need for New Physics in the Gamma-Ray Sky
journal, November 2018

  • Broderick, Avery E.; Tiede, Paul; Chang, Philip
  • The Astrophysical Journal, Vol. 868, Issue 2
  • DOI: 10.3847/1538-4357/aae5f2

DISCOVERY OF GeV EMISSION FROM THE CIRCINUS GALAXY WITH THE FERMI LARGE AREA TELESCOPE
journal, December 2013


A catalogue of quasars and active nuclei: 13th edition
journal, July 2010


The spectra of narrow-line Seyfert 1 galaxies
journal, October 1985

  • Osterbrock, D. E.; Pogge, R. W.
  • The Astrophysical Journal, Vol. 297
  • DOI: 10.1086/163513

The 2009 multiwavelength campaign on Mrk 421: Variability and correlation studies
journal, April 2015


The Nature of Transition Blazars
journal, November 2014


Chandra Observation of 3C 212: A New Look at the X‐Ray and Ultraviolet Absorbers
journal, November 2003

  • Aldcroft, T. L.; Siemiginowska, A.; Elvis, M.
  • The Astrophysical Journal, Vol. 597, Issue 2
  • DOI: 10.1086/378640

MOJAVE. XVII. Jet Kinematics and Parent Population Properties of Relativistically Beamed Radio-loud Blazars
journal, March 2019


On the Redshift of TeV BL Lac Objects
journal, March 2017


The Second Catalog of Flaring Gamma-Ray Sources from the Fermi All-sky Variability Analysis
journal, August 2017


Searching for γ -ray signature in WHSP blazars
journal, February 2017


THE CONTRIBUTION OF FERMI -2LAC BLAZARS TO DIFFUSE TEV–PEV NEUTRINO FLUX
journal, January 2017


RoboPol: the optical polarization of gamma-ray-loud and gamma-ray-quiet blazars
journal, September 2016

  • Angelakis, E.; Hovatta, T.; Blinov, D.
  • Monthly Notices of the Royal Astronomical Society, Vol. 463, Issue 3
  • DOI: 10.1093/mnras/stw2217

Looking for the least luminous BL Lacertae objects
journal, August 2015


The 5th edition of the Roma-BZCAT. A short presentation
journal, April 2015


The Compact Core-Jet Region of the Superluminal Quasar 3C 216
journal, December 2000

  • Paragi, Zsolt; Frey, Sándor; Fejes, István
  • Publications of the Astronomical Society of Japan, Vol. 52, Issue 6
  • DOI: 10.1093/pasj/52.6.983

Optical characterization of WISE selected blazar candidates
journal, September 2019

  • de Menezes, Raniere; Peña-Herazo, Harold A.; Marchesini, Ezequiel J.
  • Astronomy & Astrophysics, Vol. 630
  • DOI: 10.1051/0004-6361/201936195

The Ninth data Release of the Sloan Digital sky Survey: First Spectroscopic data from the Sdss-Iii Baryon Oscillation Spectroscopic Survey
journal, November 2012

  • Ahn, Christopher P.; Alexandroff, Rachael; Allende Prieto, Carlos
  • The Astrophysical Journal Supplement Series, Vol. 203, Issue 2
  • DOI: 10.1088/0067-0049/203/2/21

A New Complete Sample of Submillijansky Radio Sources: An Optical and Near‐Infrared Study
journal, January 2001

  • Masci, Frank J.; Condon, J. J.; Barlow, T. A.
  • Publications of the Astronomical Society of the Pacific, Vol. 113, Issue 779
  • DOI: 10.1086/317978