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Related papers: Unresolved Gamma-Ray Sky through its Angular Power…

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We present the results of an all-sky radio survey between 5 and 9 GHz of the fields surrounding all unassociated gamma-ray objects listed in the Fermi Large Area Telescope Second Source Catalog (2FGL). The goal of these observations is to…

High Energy Astrophysical Phenomena · Physics 2015-03-12 Frank K. Schinzel , Leonid Petrov , Gregory B. Taylor , Elizabeth K. Mahony , Philip G. Edwards , Yuri Y. Kovalev

The prompt emission mechanism of gamma-ray bursts (GRBs) is still unclear, and the time-resolved spectral analysis of GRBs is a powerful tool for studying their underlying physical processes. We performed a detailed time-resolved spectral…

High Energy Astrophysical Phenomena · Physics 2024-01-29 Wan-Kai Wang , Wei Xie , Zhi-Fu Gao , Shuo Xiao , Ai-Jun Dong , Bin Zhang , Qi-Jun Zhi

Following its launch in June 2008, the Fermi Gamma-ray Space Telescope (Fermi) began a sky survey in August. The Large Area Telescope (LAT) on Fermi in 3 months produced a deeper and better-resolved map of the gamma-ray sky than any…

High Energy Astrophysical Phenomena · Physics 2009-07-06 A. A. Abdo

Recent results from the PAMELA, ATIC, PPB BETS and Fermi collaborations extend the energy range in the electron flux measurement up to unexplored energies in the hundred GeVs range confirming the bump starting at about 10GeV already…

High Energy Astrophysical Phenomena · Physics 2014-11-18 Ignacio Cernuda

We study the capabilities of the Fermi-LAT instrument on board of the Fermi mission to constrain particle dark matter properties, as annihilation cross section, mass and branching ratio into dominant annihilation channels, with gamma-ray…

High Energy Astrophysical Phenomena · Physics 2017-02-22 Nicolas Bernal , Sergio Palomares-Ruiz

The nature of most of the ~300 high-energy gamma-ray sources discovered by the EGRET instrument aboard the Gamma-ray Observatory (GRO) between 1991 and 1999 is one of the greatest enigmas in high-energy astrophysics. While about half of the…

High Energy Astrophysical Phenomena · Physics 2009-02-05 R. P. Mignani

The second Fermi-LAT source catalog (2FGL) is the deepest all-sky survey available in the gamma-ray band. It contains 1873 sources, of which 576 remain unassociated. Machine-learning algorithms can be trained on the gamma-ray properties of…

High Energy Astrophysical Phenomena · Physics 2014-01-29 M. Doert , M. Errando

The origin of the cosmic gamma-ray background (CGB) is a longstanding mystery in high-energy astrophysics. Possible candidates include ordinary astrophysical objects such as unresolved blazars, as well as more exotic processes such as dark…

Astrophysics · Physics 2008-11-26 Shin'ichiro Ando , Eiichiro Komatsu , Takuro Narumoto , Tomonori Totani

Spatial extension is an important characteristic for correctly associating gamma-ray-emitting sources with their counterparts at other wavelengths and for obtaining an unbiased model of their spectra. We present a new method for quantifying…

Since its successful launch in June 2008, the {\it Fermi} Gamma-ray Space Telescope has made important breakthroughs in the understanding of the Gamma-Ray Burst (GRB) phenomemon. The combination of the GBM and the LAT instruments onboard…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Frederic Piron , Valerie Connaughton

Observations of Gamma-Ray Bursts with the Fermi Large Area Telescope have prompted theoretical advances and posed big challenges in the understanding of such extreme sources, despite the fact that GRB emission above 100 MeV is a fairly rare…

High Energy Astrophysical Phenomena · Physics 2015-02-12 Giacomo Vianello , Nicola Omodei , Fermi/LAT collaboration

Star-forming galaxies are predicted to contribute considerably to the cosmic gamma-ray background (CGB) as they are confirmed gamma-ray emitters and are the most numerous population of gamma-ray sources, although individually faint. Even…

High Energy Astrophysical Phenomena · Physics 2009-12-18 Shin'ichiro Ando , Vasiliki Pavlidou

Fast radio bursts (FRBs) are one of the most exciting new mysteries of astrophysics. Their origin is still unknown, but recent observations seems to link them to Soft Gamma Repeaters and, in particular, to magnetar giant flares (MGFs). The…

High Energy Astrophysical Phenomena · Physics 2021-09-23 Giacomo Principe , Nicola Omodei , Niccolò Di Lalla , Leonardo Di Venere , Francesco Longo

The Fermi Gamma-ray Space Telescope (Fermi) was launched on June 11, 2008 and began its first year sky survey on August 11, 2008. The Large Area Telescope (LAT), a wide field-of-view pair-conversion telescope covering the energy range from…

High Energy Astrophysical Phenomena · Physics 2010-11-30 Peter F. Michelson , William B. Atwood , Steven Ritz

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

Context: Despite more than half a century of research, the dominant radiation mechanism of gamma-ray burst (GRB) prompt emission remains unsolved. Some progress has been made through the analyses of the observational spectra of Swift/BAT,…

High Energy Astrophysical Phenomena · Physics 2026-02-11 Yan-Zhi Meng , Shu-Qing Zhong , Jia-Hong Gu , Xin-Fei Li , Xiaozhou Zhao

We report the detection of two new gamma-ray sources in the Fermi-LAT sky (Pass 8) at energies higher than 20 GeV, and confirmed at lower energies, using a source detection tool based on the Minimum Spanning Tree algorithm. One of these…

High Energy Astrophysical Phenomena · Physics 2017-01-25 R. Campana , A. Maselli , E. Bernieri , E. Massaro

From the launch of the Fermi Gamma-ray Space Telescope to July 9, 2010, the Gamma-ray Burst Monitor (GBM) has detected 497 probable GRB events. Twenty-two of these satisfy the simultaneous requirements of an estimated burst direction within…

High Energy Astrophysical Phenomena · Physics 2015-05-20 C. W. Akerlof , W. Zheng , S. B. Pandey , T. A. McKay

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

The Fermi Gamma-ray Space Telescope is producing the most detailed inventory of the gamma-ray sky to date. Despite tremendous achievements approximately 25% of all Fermi extragalactic sources in the Second Fermi LAT Catalogue (2FGL) are…

High Energy Astrophysical Phenomena · Physics 2012-12-12 T. Hassan , N. Mirabal , J. L. Contreras , I. Oya