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Related papers: Fermi-LAT improved Pass~8 event selection

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With assistance of the identified/associated sources in the second Fermi Large Area Telescope (LAT) catalog, we analyze and resolve the spatial distribution and the distributions of the gamma-ray spectral and variability indices of the…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Zhu Mao , Yun-Wei Yu

The Fermi Large Area Telescope has observed an excess of ~GeV energy gamma rays from the center of the Milky Way, which may arise from near-thermal dark matter annihilation. Firmly establishing the dark matter origin for this excess is…

High Energy Astrophysical Phenomena · Physics 2020-07-22 Malte Buschmann , Nicholas L. Rodd , Benjamin R. Safdi , Laura J. Chang , Siddharth Mishra-Sharma , Mariangela Lisanti , Oscar Macias

Following our work presented in Dai et al. (2016), we report our detailed data analysis for another 38 Fermi gamma-ray un-associated sources. These sources are selected from the Fermi Large Area Telescope (LAT) third source catalog on the…

High Energy Astrophysical Phenomena · Physics 2021-06-03 Xuejie Dai , Zhongxiang Wang , V. Jithesh , Yi Xing

Observations by the Large Area Telescope (LAT) on the \textit{Fermi} mission of diffuse $\gamma$-rays in a mid-latitude region in the third quadrant (Galactic longitude $l$ from $200\arcdeg$ to $260\arcdeg$ and latitude $| b |$ from…

High Energy Astrophysical Phenomena · Physics 2009-12-04 A. A. Abdo

We analyze the recently released Fermi-LAT data on the sum of electrons and positrons. Compared to a conventional, pre-Fermi, background model, a surprising excess in the several hundred GeV range is found and here we analyze it in terms of…

High Energy Astrophysical Phenomena · Physics 2009-09-02 Lars Bergstrom , Joakim Edsjo , Gabrijela Zaharijas

Either ATIC or Fermi-LAT data can be fitted together with the PAMELA data by three components: primary background ~ E^{-3.3}, secondary background ~ E^{-3.6}, and an additional source of electrons ~ E^{-g_a} Exp(-E/E_{cut}). We find that…

High Energy Astrophysical Phenomena · Physics 2009-07-30 Dmitry Malyshev

The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope routinely detects the highly dust-absorbed, reddened, and MeV-peaked flat spectrum radio quasar PKS 1830-211 (z=2.507). Its apparent isotropic gamma-ray luminosity…

High Energy Astrophysical Phenomena · Physics 2015-06-23 The Fermi LAT Collaboration , A. A. Abdo , M. Ackermann , M. Ajello , A. Allafort , M. A. Amin , L. Baldini , G. Barbiellini , D. Bastieri , K. Bechtol , R. Bellazzini , R. D. Blandford , E. Bonamente , A. W. Borgland , J. Bregeon , M. Brigida , R. Buehler , D. Bulmash , S. Buson , G. A. Caliandro , R. A. Cameron , P. A. Caraveo , E. Cavazzuti , C. Cecchi , E. Charles , C. C. Cheung , J. Chiang , G. Chiaro , S. Ciprini , R. Claus , J. Cohen-Tanugi , J. Conrad , R. H. D. Corbet , S. Cutini , F. D'Ammando , A. de Angelis , F. de Palma , C. D. Dermer , P. S. Drell , A. Drlica-Wagner , C. Favuzzi , J. Finke , W. B. Focke , Y. Fukazawa , P. Fusco , F. Gargano , D. Gasparrini , N. Gehrels , N. Giglietto , F. Giordano , M. Giroletti , T. Glanzman , I. A. Grenier , J. E. Grove , S. Guiriec , D. Hadasch , M. Hayashida , E. Hays , R. E. Hughes , Y. Inoue , M. S. Jackson , T. Jogler , G. Jòhannesson , A. S. Johnson , T. Kamae , J. Knödlseder , M. Kuss , J. Lande , S. Larsson , L. Latronico , F. Longo , F. Loparco , B. Lott , M. N. Lovellette , P. Lubrano , G. M. Madejski , M. N. Mazziotta , J. Mehault , P. F. Michelson , T. Mizuno , M. E. Monzani , A. Morselli , I. V. Moskalenko , S. Murgia , R. Nemmen , E. Nuss , M. Ohno , T. Ohsugi , D. Paneque , J. S. Perkins , M. Pesce-Rollins , F. Piron , G. Pivato , T. A. Porter , S. Rainò , R. Rando , M. Razzano , A. Reimer , O. Reimer , L. C. Reyes , S. Ritz , C. Romoli , M. Roth , P. M. Saz Parkinson , C. Sgrò , E. J. Siskind , G. Spandre , P. Spinelli , H. Takahashi , Y. Takeuchi , T. Tanaka , J. G. Thayer , J. B. Thayer , D. J. Thompson , L. Tibaldo , M. Tinivella , D. F. Torres , G. Tosti , E. Troja , V. Tronconi , T. L. Usher , J. Vandenbroucke , V. Vasileiou , G. Vianello , V. Vitale , A. P. Waite , M. Werner , B. L. Winer , K. S. Wood

FERMI-LAT is performing an all-sky gamma-ray survey from 20 MeV to >300 GeV with unprecedented sensitivity and angular resolution. FERMI is the only mission able to detect high energy (>20 MeV) emission from the Sun during the new solar…

Solar and Stellar Astrophysics · Physics 2019-08-15 G. Iafrate , F. Longo , N. Giglietto , M. Brigida

Sensitivity of searches for extended emission around gamma-ray sources is naturally limited by the precision of the knowledge of the Point Spread Function (PSF) of gamma-ray telescopes. Inaccuracies in the PSF models of the Fermi Large Area…

High Energy Astrophysical Phenomena · Physics 2026-02-17 J. Blunier , A. Neronov , D. Semikoz

We present gamma-ray observations with the LAT on board the Fermi Gamma-Ray Telescope of the nearby radio galaxy Centaurus~A. The previous EGRET detection is confirmed, and the localization is improved using data from the first 10 months of…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Fermi Collaboration , A. Falcone , H. Hase , C. Pagoni , C. Ploetz

Observations of distant gamma-ray sources are hindered by the presence of the extragalactic background light (EBL). In order to understand the physical processes that result in the observed spectrum of sources, it is imperative that a good…

High Energy Astrophysical Phenomena · Physics 2017-06-01 Thomas Armstrong , Anthony M. Brown , Paula M. Chadwick

This catalog summarizes 117 high-confidence > 0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data, through…

High Energy Astrophysical Phenomena · Physics 2013-09-25 LAT collaboration

We are starting a project to find $\gamma$-ray millisecond pulsars (MSPs) among the unidentified sources detected by the Large Area Telescope (LAT) onboard the {Fermi Gamma-Ray Space Telescope (Fermi)}, by radio observations. The selection…

High Energy Astrophysical Phenomena · Physics 2019-03-04 Xuejie Dai , Zhongxiang Wang , Jithesh Vadakkumthani

Unassociated Fermi-LAT sources provide a population with discovery potential. We discuss efforts to find new source associations for this population, and summarize the successes to date. We discuss how the measured gamma-ray properties of…

High Energy Astrophysical Phenomena · Physics 2012-06-13 Elizabeth C. Ferrara , Roopesh Ojha , Maria Elena Monzani , Nicola Omodei

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

This paper presents the gamma-ray spectral and timing results from the long-term regular observations of Mrk 421 with the Large Area Telescope (LAT) onboard Fermi during 2008 August - 2023 August. We discerned six periods the relatively…

High Energy Astrophysical Phenomena · Physics 2025-03-05 B. Kapanadze , A. Gurchumelia , M. Aller

We report the Fermi Large Area Telescope (LAT) detection of a $\gamma$-ray source at the position of SAX J1808.4$-$3658. This transient low-mass X-ray binary contains an accreting millisecond puslar, which is only seen during its month-long…

High Energy Astrophysical Phenomena · Physics 2015-02-04 Yi Xing , Zhongxiang Wang , V. Jithesh

In principle, the angular anisotropy in the extragalactic gamma-ray background (EGRB) places severe constraints upon putative populations of unresolved gamma-ray point sources. Existing estimates of the EGRB anisotropy have been constructed…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-02 Avery E. Broderick , Christoph Pfrommer , Ewald Puchwein , Philip Chang , Kendrick M. Smith

AIMS. We are studying an unbiased sample of 42 nearby (z < 0.2) BL Lacertae objects with a multi-wavelength approach. The results of VLBI observations were presented in the first paper of this series. In this paper, we study the…

High Energy Astrophysical Phenomena · Physics 2018-11-08 F. D'Ammando , M. Giroletti , S. Rainò

The Fermi-LAT collaboration has studied the gamma-ray emission from a stacked population of dwarf spheroidal galaxies and used this information to set constraints on the dark matter annihilation cross section. Interestingly, their analysis…

High Energy Astrophysical Phenomena · Physics 2015-03-11 Eric Carlson , Dan Hooper , Tim Linden