Results 41 to 50 of about 309 (157)
Upper limit on the axion-photon coupling from Markarian 421
Physics Letters BMarkarian421 is a well-known nearby BL Lac blazar at the redshift z=0.031. Many previous works were investigated to constrain the axion-photon coupling from its TeV gamma-ray observations, showing the upper limit on the coupling constant gaγ≲2.0×10−11GeV−
Hai-Jun Li, Wei Chao, Yu-Feng Zhou
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Relativistic Jets in Gamma-Ray-Emitting Narrow-Line Seyfert 1 Galaxies
Galaxies, 2019 Before the launch of the Fermi Gamma-ray Space Telescope satellite only two classes of active galactic nuclei (AGN) were known to generate relativistic jets and thus to emit up to the γ -ray energy range: blazars and radio galaxies, both hosted
Filippo D’Ammando
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On the Gamma-Ray Emission of the Andromeda Galaxy M31
The Astrophysical Journal Letters, 2023 Using the γ -ray data obtained with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope (Fermi) for ∼14 yr, we examine the high-energy emission emanating from the center of the Andromeda galaxy M31.
Yi Xing +3 more
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Pre-burst events of gamma-ray bursts with light speed variation
Physics Letters B, 2021 Previous researches on high-energy photon events from gamma-ray bursts (GRBs) suggest a light speed variation v(E)=c(1−E/ELV) with ELV=3.6×1017 GeV, together with a pre-burst scenario that hight-energy photons come out about 10 seconds earlier than low ...
Jie Zhu, Bo-Qiang Ma
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Model of gamma sky for the Fermi Gamma-ray Space Telescope (FGST) [PDF]
, 2010 A number of important parameters of cosmic-ray distribution, propagation, and interaction in the Milky Way can be predicted through the comparison of measured cosmic-ray and gamma-ray spectra to the spectra of simulated Galaxies. These predictions are made by altering the physical parameters governing Galaxy simulations until a best-fit set of ...
McLeod, Andrew +3 more
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The Fermi GBM and LAT follow-up of GW150914
EPJ Web of Conferences, 2017 As the first detection of Gravitation Wave (GW) event arising from the coalescence of two stellar-mass Black Holes (BH) was announced by LIGO, a new era for astronomy began.
Bissaldi E. +5 more
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Galaxies, 2020 Since the launch of Chandra twenty years ago, one of the greatest mysteries surrounding Quasar Jets is the production mechanism for their extremely high X-ray luminosity. Two mechanisms have been proposed. In the first view, the X-ray emission is inverse-
Eric S. Perlman +6 more
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The Astrophysical Journal, 2023 We report our analysis results for the globular cluster (GC) NGC 6341 (M92), as a millisecond pulsar (MSP) J1717+4308A has recently been reported found in this GC.
Pengfei Zhang +4 more
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Exploring the extreme universe with the Fermi Gamma-Ray Space Telescope [PDF]
Physics Today, 2012 The Fermi orbiter, mapping the entire gamma-ray sky every three hours, monitors the cosmos for high-energy phenomena both fleeting and enduring.
David J. Thompson +2 more
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Pre-burst neutrinos of gamma-ray bursters accompanied by high-energy photons
Physics Letters B, 2021 Previous researches on high-energy neutrino events from gamma-ray bursters (GRBs) suggest a neutrino speed variation v(E)=c(1±E/ELVν) with ELVν=(6.4±1.5)×1017 GeV, together with an intrinsic time difference Δtin=(−2.8±0.7)×102 s, which means that high ...
Jie Zhu, Bo-Qiang Ma
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