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Related papers: Identifying the 3FHL catalog: CTIO results

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Observations of the gamma-ray sky with Fermi led to significant advances towards understanding blazars, the most extreme class of Active Galactic Nuclei. A large fraction of the population detected by Fermi is formed by BL Lacertae (BL Lac)…

We present a catalog of sources detected above 10 GeV by the Fermi Large Area Telescope (LAT) in the first 7 years of data using the Pass 8 event-level analysis. This is the Third Catalog of Hard Fermi-LAT Sources (3FHL), containing 1556…

High Energy Astrophysical Phenomena · Physics 2017-10-25 LAT Collaboration

We investigate the spectroscopic optical properties of gamma-ray sources detected with high significance above 50 GeV in the Third Catalog of Hard Fermi-LAT Sources (3FHL) and that are good candidates as TeV emitters. We focus on the 91…

Astrophysics of Galaxies · Physics 2020-07-08 Simona Paiano , Renato Falomo , Aldo Treves , Riccardo Scarpa

In the recently published 3FGL catalogue, the Fermi/LAT collaboration reports the detection of $\gamma$-ray emission from 3034 sources obtained after four years of observations. The nature of 1010 of those sources is unknown, whereas 2023…

High Energy Astrophysical Phenomena · Physics 2017-06-21 J. Lefaucheur , S. Pita

We present the results of an identification campaign of unassociated sources from the Fermi Large Area Telescope 3FHL catalog. Out of 200 unidentified sources, we selected 110 sources for which archival Swift-XRT observations were…

High Energy Astrophysical Phenomena · Physics 2019-01-25 Amanpreet Kaur , Marco Ajello , Stefano Marchesi , Nicola Omodei

We present the third Fermi Large Area Telescope source catalog (3FGL) of sources in the 100 MeV-300 GeV range. Based on the first four years of science data from the Fermi Gamma-ray Space Telescope mission, it is the deepest yet in this…

High Energy Astrophysical Phenomena · Physics 2015-06-10 LAT Collaboration

Blazars are active galactic nuclei, and the most numerous High Energy (HE) and Very High Energy (VHE) gamma-ray emitters. Their optical emission is often dominated by non-thermal, and, in the case of BL Lacs, featureless continuum…

High Energy Astrophysical Phenomena · Physics 2019-08-14 P. Goldoni , S. Pita , C. Boisson , G. Cotter , D. A. Williams , E. Lindfors

Blazars, one of the most extreme class of active galaxies, constitute so far the largest known population of $\gamma$-ray sources and their number is continuously growing in the Fermi catalogs. However in the latest release of the Fermi…

We present the first catalog of active galactic nuclei (AGN) detected by the LAT, corresponding to 11 months of data collected in scientific operation mode. The First LAT AGN Catalog (1LAC) includes 671 gamma-ray sources located at high…

High Energy Astrophysical Phenomena · Physics 2019-08-14 A. A. Abdo

The Fermi Large Area Telescope (LAT) Collaboration has recently released the Third Catalog of Hard Fermi-LAT Sources (3FHL), which contains 1556 sources detected above 10 GeV with seven years of Pass 8 data. We investigate the source count…

High Energy Astrophysical Phenomena · Physics 2021-12-07 Mattia Di Mauro , Silvia Manconi , Hannes-S. Zechlin , Marco Ajello , Eric Charles , Fiorenza Donato

The first three months of sky-survey operation with the Fermi Gamma Ray Space Telescope (Fermi) Large Area Telescope (LAT) reveals 132 bright sources at |b|>10 deg with test statistic greater than 100 (corresponding to about 10 sigma). Two…

High Energy Astrophysical Phenomena · Physics 2009-09-30 A. A. Abdo

During its first four years of scientific observations, the Fermi Large Area Telescope (Fermi-LAT) detected 3033 $\gamma$-ray sources above a 4$\sigma$ significance level. Although most of the extra-Galactic sources are active galactic…

High Energy Astrophysical Phenomena · Physics 2019-08-15 G. La Mura , G. Chiaro , S. Ciroi , P. Rafanelli , D. Salvetti , M. Berton , V. Cracco

In the last two decades, very-high-energy gamma-ray astronomy has reached maturity: over 200 sources have been detected, both Galactic and extragalactic, by ground-based experiments. At present, Active Galactic Nuclei (AGN) make up about…

Despite the fact that blazars constitute the rarest class among active galactic nuclei (AGNs) they are the largest known population of associated $\gamma$-ray sources. Many of the $\gamma$-ray objects listed in the Fermi-Large Area…

Context. Blazars are a distinct subclass of active galactic nuclei (AGN), known for their fast variability, high polarization, and intense emission across the electromagnetic spectrum, from radio waves to gamma rays. Gamma-ray blazar…

High Energy Astrophysical Phenomena · Physics 2025-01-08 N. Álvarez Crespo , A. Domínguez , V. S. Paliya , M. Chamorro Cazorla , P. Sánchez Blázquez , A. Gil de Paz

BL Lacertae objects (BL Lacs) represent a large fraction (22\%) of gamma-ray sources in the Third Fermi Large Area Telescope catalog (3FGL). Nearly half of the BL Lac population remains without a redshift because of their featureless…

High Energy Astrophysical Phenomena · Physics 2020-07-29 M. Rajagopal , A. Kaur , A. Ajello , A. Rau , A. Domínguez , B. Cenko , J. Greiner , D. Hartmann

The extragalactic $\gamma$-rays sky observed by Fermi-Large Area Telescope (LAT) is dominated by blazars. In the fourth release of the Fermi-LAT Point Source Catalog (4FGL), are sources showing a multifrequency behavior similar to that of…

The Third Catalog of Hard Fermi Large Area Telescope Sources (3FHL) reports the detection of 1556 objects at E > 10 GeV. However, 177 sources remain unassociated and 23 are associated with a ROSAT X-ray detection of unknown origin. Pointed…

High Energy Astrophysical Phenomena · Physics 2022-12-07 S. Joffre , R. Silver , M. Rajagopal , M. Ajello , N. Torres-Albà , A. Pizzetti , S. Marchesi , A. Kaur

Searching for low energy counterparts of gamma-ray sources is one of the major challenges in modern gamma-ray astronomy. In the third Fermi source catalog about 30 % of detected sources are unidentified/unassociated Gamma-ray Sources…

Astrophysics of Galaxies · Physics 2019-03-26 Peña-Herazo , H. A. , Marchesini , E. J. , Álvarez Crespo , N. , Ricci , F. , Massaro , F. , Chavushyan , V. , Landoni , M. , Strader , J. , Chomiuk , L. , Cheung , C. C. , Masetti , N. , Jiménez-Bailón , E. , D'Abrusco , R. , Paggi , A. , Milisavljevic , D. , La Franca , F. , Smith , H. A. , Tosti , G.

We considered the fourth catalog of gamma-ray point sources produced by the Fermi Large Area Telescope (LAT) and selected only jetted active galactic nuclei (AGN) or sources with no specific classification, but with a low-frequency…