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Related papers: Identification of 4FGL uncertain sources at Higher…

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In this work, Machine Learning (ML) methods are used to efficiently identify the unassociated sources and the Blazar Candidate of Uncertain types (BCUs) in the Fermi-LAT Third Source Catalog (3FGL). The aims are twofold: 1) to distinguish…

High Energy Astrophysical Phenomena · Physics 2020-05-08 Hubing Xiao , Haitao Cao , Junhui Fan , Denise Costantin , Gaoyong Luo , Zhiyuan Pei

In the fourth \emph{Fermi} Large Area Telescope source catalog (4FGL), 5064 $\gamma$-ray sources are reported, including 3207 active galactic nuclei (AGNs), 239 pulsars, 1336 unassociated sources, 92 sources with weak association with…

High Energy Astrophysical Phenomena · Physics 2021-02-10 Kerui Zhu , Shi-Ju Kang , Yong-Gang Zheng

We present a systematic reassessment of 5,062 high-Galactic latitude gamma-ray sources from the Fermi-LAT 4FGL-DR4 catalog using Firmamento, a web-based platform for multi-frequency source discovery and analysis. Our goal is to provide an…

The deepest all-sky survey available in the $\gamma$-ray band - the last release of the Fermi-LAT catalogue (4FGL-DR3) based on the data accumulated in 12 years, contains more than 6600 sources. The largest population among the sources is…

High Energy Astrophysical Phenomena · Physics 2022-12-28 N. Sahakyan , V. Vardanyan , M. Khachatryan

The classifications of Fermi-LAT unassociated sources are studied using multiple machine learning (ML) methods. The update data from 4FGL-DR3 are divided into high Galactic latitude (HGL, Galactic latitude $|b|>10^\circ$) and low Galactic…

High Energy Astrophysical Phenomena · Physics 2023-11-08 K. R. Zhu , J. M. Chen , Y. G. Zheng , L. Zhang

The Fermi fourth catalog of active galactic nuclei (AGNs) data release 3 (4LAC-DR3) contains 3407 AGNs, out of which 755 are flat spectrum radio quasars (FSRQs), 1379 are BL Lacertae objects (BL Lacs), 1208 are blazars of unknown (BCUs)…

High Energy Astrophysical Phenomena · Physics 2023-04-12 Aditi Agarwal

Machine learning has emerged as a powerful tool in the field of gamma-ray astrophysics. The algorithms can distinguish between different source types, such as blazars and pulsars, and help uncover new insights into the high-energy universe.…

High Energy Astrophysical Phenomena · Physics 2024-01-05 Gopal Bhatta , Sarvesh Gharat , Abhimanyu Borthakur , Aman Kumar

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

The second Fermi-LAT source catalog (2FGL) is the deepest survey of the gamma-ray sky ever compiled, containing 1873 sources that constitute a very complete sample down to an energy flux of about 10^(-11) erg cm^(-2) s^(-1). While…

High Energy Astrophysical Phenomena · Physics 2013-07-01 M. Doert , M. Errando

The Fermi-LAT DR1 and DR2 4FGL catalogues feature more than 5000 gamma-ray sources of which about one fourth are not associated with already known objects, and approximately one third are associated with blazars of uncertain nature. We…

High Energy Astrophysical Phenomena · Physics 2021-06-30 S. Germani , G. Tosti , . Lubrano , S. Cutini , I. Mereu , A. Berretta

Among the ~2157 unassociated sources in the third data release (DR3) of the fourth Fermi catalog, ~1200 were observed with the Neil Gehrels Swift Observatory pointed instruments. These observations yielded 238 high S/N X-ray sources within…

High Energy Astrophysical Phenomena · Physics 2023-02-15 Amanpreet Kaur , Stephen Kerby , Abraham D. Falcone

The recently published fourth Fermi Large Area Telescope source catalog (4FGL) reports 5065 gamma-ray sources in terms of direct observational gamma-ray properties. Among the sources, the largest population is the Active Galactic Nuclei…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Shi-Ju Kang , Enze Li , Wujing Ou , Kerui Zhu , Jun-Hui Fan , Qingwen Wu , Yue Yin

We present the first Fermi Large Area Telescope (LAT) catalog of long-term $\gamma$-ray transient sources (1FLT). This comprises sources that were detected on monthly time intervals during the first decade of Fermi-LAT operations. The…

High Energy Astrophysical Phenomena · Physics 2021-09-29 L. Baldini , J. Ballet , D. Bastieri , J. Becerra Gonzalez , R. Bellazzini , A. Berretta , E. Bissaldi , R. D. Blandford , E. D. Bloom , R. Bonino , E. Bottacini , P. Bruel , S. Buson , R. A. Cameron , P. A. Caraveo , E. Cavazzuti , S. Chen , G. Chiaro , D. Ciangottini , S. Ciprini , P. Cristarella Orestano , M. Crnogorcevic , S. Cutini , F. D'Ammando , P. de la Torre Luque , F. de Palma , S. W. Digel , N. Di Lalla , F. Dirirsa , L. Di Venere , A. Domínguez , A. Fiori , H. Fleischhack , A. Franckowiak , Y. Fukazawa , S. Funk , P. Fusco , F. Gargano , D. Gasparrini , S. Germani , N. Giglietto , F. Giordano , M. Giroletti , D. Green , I. A. Grenier , S. Griffin , S. Guiriec , M. Gustafsson , J. W. Hewitt , D. Horan , R. Imazawa , G. Jóhannesson , M. Kerr , D. Kocevski , M. Kuss , S. Larsson , L. Latronico , J. Li , I. Liodakis , F. Longo , F. Loparco , M. N. Lovellette , P. Lubrano , S. Maldera , A. Manfreda , G. Martí-Devesa , H. Matake , M. N. Mazziotta , I. Mereu , M. Meyer , N. Mirabal , W. Mitthumsiri , T. Mizuno , M. E. Monzani , A. Morselli , I. V. Moskalenko , S. Nagasawa , M. Negro , R. Ojha , M. Orienti , E. Orlando , M. Palatiello , V. Paliya , D. Paneque , Z. Pei , M. Persic , M. Pesce-Rollins , V. Petrosian , H. Poon , T. A. Porter , G. Principe , J. L. Racusin , S. Rainò , R. Rando , B. Rani , M. Razzano , S. Razzaque , A. Reimer , O. Reimer , P. M. Saz Parkinson , L. Scotton , D. Serini , C. Sgrò , E. J. Siskind , G. Spandre , P. Spinelli , D. J. Suson , H. Tajima , D. Tak , D. F. Torres , G. Tosti , E. Troja , K. Wood , M. Yassine , G. Zaharijas

We utilize machine learning methods to distinguish BL Lacertae objects (BL Lac) from Flat Spectrum Radio Quasars (FSRQ) within a sample of likely X-ray blazar counterparts to Fermi 3FGL unassociated gamma-ray sources. From our previous…

High Energy Astrophysical Phenomena · Physics 2021-03-03 Amanpreet Kaur , Abraham D. Falcone , Michael C. Stroh

A sample of 312 low-frequency peaked BL Lacertae objects (LBLs) and 694 flat spectrum radio quasars (FSRQs) with the parameters both redshift and $\gamma$-ray photon spectral index ($\Gamma _\gamma$) is compiled from the active galactic…

High Energy Astrophysical Phenomena · Physics 2025-03-31 S. Liang , W. G. Yang , Y. G. Zheng , S. J. Kang

We present a wavelet-based algorithm to identify dwarf galaxies in the Milky Way in ${\it Gaia}$ DR2 data. Our algorithm detects overdensities in 4D position--proper motion space, making it the first search to explicitly use velocity…

Astrophysics of Galaxies · Physics 2021-07-15 Elise Darragh-Ford , Ethan O. Nadler , Sean McLaughlin , Risa H. Wechsler

The Large Area Telescope (LAT) on board the \emph{Fermi} Gamma-ray Space Telescope has been continuously providing good quality survey data of the entire sky in the high energy range from 30 MeV to 500 GeV and above since August 2008. A…

High Energy Astrophysical Phenomena · Physics 2025-10-13 A. Pathania , K. K. Singh , S. K. Singh , A. Tolamatti , B. B. Singh , K. K. Yadav

Machine learning based approaches are emerging as very powerful tools for many applications including source classification in astrophysics research due to the availability of huge high quality data from different surveys in observational…

High Energy Astrophysical Phenomena · Physics 2023-07-05 A. Tolamatti , K. K. Singh , K. K. Yadav

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 its first four years of operation, the Fermi Large Area Telescope (LAT) detected 3033 $\gamma$-ray emitting sources. In the Fermi-LAT Third Source Catalogue (3FGL) about 50% of the sources have no clear association with a likely…

High Energy Astrophysical Phenomena · Physics 2017-07-19 David Salvetti , Graziano Chiaro , Giovanni La Mura , David J. Thompson
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