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Related papers: Is the stellar system WR 11 a gamma-ray source?

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We report the discovery of MeV-GeV gamma-ray emission by the Fermi-LAT positionally coincident with the TeV pulsar wind nebula (PWN) HESS~J1554-550 within the host supernova remnant (SNR) G327.1-1.1. The gamma-ray emission is point-like and…

High Energy Astrophysical Phenomena · Physics 2022-12-07 Jordan Eagle , Daniel Castro , Tea Temim , Jean Ballet , Patrick Slane , Joseph Gelfand , Matthew Kerr , Marco Ajello

Gamma-ray binaries are orbital modulated gamma-ray sources in the Galaxy detected both at GeV and TeV energies. The high-energy radiation may come from the interaction of energetic electrons injected by a young pulsar and photons from the…

High Energy Astrophysical Phenomena · Physics 2009-12-21 B. Cerutti , G. Dubus , G. Henri

Recent observations with the Chandra X-ray telescope continue to detect X-ray emission from the transient GW170817. In a total exposure of 96.6 ks, performed between March 9 and March 16 2020 (935 d to 942 d after the merger), a total of 8…

High Energy Astrophysical Phenomena · Physics 2020-10-21 E. Troja , H. van Eerten , B. Zhang , G. Ryan , L. Piro , R. Ricci , B. O'Connor , M. H. Wieringa , S. B. Cenko , T. Sakamoto

In recent years, systems involving massive stars with large wind kinetic power have been considered as promising sites for investigating relativistic particle acceleration in low radio frequencies. With this aim, we observed two Wolf-Rayet…

High Energy Astrophysical Phenomena · Physics 2024-06-25 Anindya Saha , Anandmayee Tej , Santiago del Palacio , Michaël De Becker , Paula Benaglia , Ishwara Chandra CH , Prachi Prajapati

WR140 is the archetype long-period colliding wind binary (CWB) system, and is well known for dramatic variations in its synchrotron emission during its 7.9-yr, highly eccentric orbit. This emission is thought to arise from relativistic…

Astrophysics · Physics 2016-08-30 J. M. Pittard , S. M. Dougherty

We cross correlate the Fermi 11 months survey catalogue (1FGL) with the 20 GHz Australia Telescope Compact Array radio survey catalogue (AT20G) composed by 5890 sources at declination <0 deg. Among the 738 Fermi sources distributed in the…

High Energy Astrophysical Phenomena · Physics 2015-05-18 G. Ghirlanda , G. Ghisellini , F. Tavecchio , L. Foschini

Observations by the Fermi-LAT have uncovered a bright, spherically symmetric excess surrounding the center of the Milky Way galaxy. The spectrum of the gamma-ray excess peaks sharply at an energy ~2 GeV, exhibiting a hard spectrum at lower…

High Energy Astrophysical Phenomena · Physics 2017-02-28 Tim Linden , Nicholas L. Rodd , Benjamin R. Safdi , Tracy R. Slatyer

We report the identification from multi-wavelength observations of the Fermi Large Area Telescope (LAT) source 4FGL J1405.1-6119 (= 3FGL J1405.4-6119) as a high-mass gamma-ray binary. Observations with the LAT show that gamma-ray emission…

High Energy Astrophysical Phenomena · Physics 2019-11-06 R. H. D. Corbet , L. Chomiuk , M. J. Coe , J. B. Coley , G. Dubus , P. G. Edwards , P. Martin , V. A. McBride , J. Stevens , J. Strader , L. J. Townsend

The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed contemporaneously by the Very Long Baseline Array (VLBA). In total, 232 sources were observed with…

There are by now ten published detections of fast radio bursts (FRBs), single bright GHz-band millisecond pulses of unknown origin. Proposed explanations cover a broad range from exotic processes at cosmological distances to atmospheric and…

Microquasars, the local siblings of extragalactic quasars, are binary systems comprising a compact object and a companion star. By accreting matter from their companions, microquasars launch powerful winds and jets, influencing the…

High Energy Astrophysical Phenomena · Physics 2020-08-25 Jian Li , Diego F. Torres , Ruo-Yu Liu , Matthew Kerr , Emma de Ona Wilhelmi , Yang Su

Flares from magnetically active dwarf stars should produce relativistic particles capable of creating gamma-rays. So far, the only isolated main sequence star besides the Sun to have been detected in gamma-rays is TVLM 513-46546. Detecting…

High Energy Astrophysical Phenomena · Physics 2024-05-27 Yuzhe Song , Timothy A. D. Paglione , Ekaterina Ilin

We report Fermi/LAT observations and broad-band spectral modeling of the radio-loud active galaxy 4C +55.17 (z=0.896), formally classified as a flat-spectrum radio quasar. Using 19 months of all-sky survey Fermi/LAT data, we detect a…

The Fermi Large Area Telescope revealed that the extragalactic gamma-ray sky is dominated by blazars, active galactic nuclei (AGN) whose jet is seen at very small angle to the line of sight. To associate and then classify the gamma-ray…

Astrophysics of Galaxies · Physics 2018-05-09 K. É. Gabányi , S. Frey , T. An

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

Very high-energy (VHE; E>100 GeV) gamma-rays have been detected from a wide range of astronomical objects, such as pulsar wind nebulae (PWNe), supernova remnants (SNRs), giant molecular clouds, gamma-ray binaries, the Galactic Center,…

High Energy Astrophysical Phenomena · Physics 2015-03-13 P. H. Thomas Tam , Stefan Wagner , Omar Tibolla , Ryan Chaves

Analyses have found a "haze" of anomalous microwave emission surrounding the Galactic Center in the WMAP sky maps. A recent study using Fermi data detected a similar haze in the gamma-ray. Several studies have modeled these hazes as…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Matthew McQuinn , Matias Zaldarriaga

The supernova remnant (SNR) G51.26+0.11 was recently discovered and little is known about its properties and environment. Using data from the \emph{Fermi} Large Area Telescope we study the GeV emission seen in the direction of G51.26+0.11…

High Energy Astrophysical Phenomena · Physics 2021-11-17 Miguel Araya

Radio and gamma-ray emission from active galactic nuclei (AGN) are thought to share a common origin, related to the ejection phenomena in the vicinity of supermassive black holes. Thanks to its sensitivity, surveying capability, and broad…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-29 M. Giroletti , A. Reimer , L. Fuhrmann , V. Pavlidou , J. L. Richards

We present a temporal and spectral analysis of the gamma-ray flux from nine of the brightest flat spectrum radio quasars (FSRQs) detected with the Fermi Large Area Telescope (LAT) during its first eight years of operation, with the aim of…

High Energy Astrophysical Phenomena · Physics 2020-11-20 Atreya Acharyya , Paula M. Chadwick , Anthony M. Brown
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