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Related papers: Gamma-Ray Line Observations with RHESSI

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Annihilating dark matter particles in nearby subhalos could generate potentially observable fluxes of gamma rays, unaccompanied by emission at other wavelengths. Furthermore, this gamma-ray emission is expected to be spatially extended,…

High Energy Physics - Phenomenology · Physics 2017-09-26 Ti-Lin Chou , Dimitrios Tanoglidis , Dan Hooper

The recent discovery of ten new dwarf galaxy candidates by the Dark Energy Survey (DES) and the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) could increase the Fermi Gamma-Ray Space Telescope's sensitivity to…

High Energy Astrophysical Phenomena · Physics 2015-09-16 Dan Hooper , Tim Linden

The Gaia mission is designed as a Galaxy explorer, and will measure simultaneously, in a survey mode, the five or six phase space parameters of all stars brighter than 20th magnitude, as well as providing a description of their…

Gamma-ray lines are traditional smoking gun signatures for dark matter annihilation in the Universe. In regions optimized for large signal-to-noise ratio, we identified a signal candidate for a gamma-ray line at energies around 130 GeV with…

High Energy Astrophysical Phenomena · Physics 2013-03-08 Christoph Weniger

The presence of radioactive $^{26}$Al at 1.8 MeV reflects ongoing nucleosynthesis in the Milky Way. Diffuse emission from its decay can be measured with gamma-ray telescopes in space. The intensity, line shape, and spatial distribution of…

High Energy Astrophysical Phenomena · Physics 2023-04-05 Moritz M. M. Pleintinger , Roland Diehl , Thomas Siegert , Jochen Greiner , Martin G. H. Krause

The determination of the densities of intergalactic photons from the FIR to the UV produced by stellar emission and dust reradiation at various redshifts can provide an independent measure of the star formation history of the universe. High…

Astrophysics · Physics 2007-05-23 F. W. Stecker

Recently, several groups identified a tentative $\gamma$-ray line signal with energy $\sim 130$ GeV in the central Galaxy from the Fermi-LAT data. %The morphology study shows that the signal is consistent with dark matter %annihilation, but…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-24 Rui-Zhi Yang , Qiang Yuan , Lei Feng , Yi-Zhong Fan , Jin Chang

High energy gamma-ray astronomy has recently made significant progresss through ground-based instruments like the {\it H.E.S.S.} array of imaging atmospheric Cherenkov telescopes. The unprecedented angular resolution and the large field of…

Astrophysics · Physics 2009-11-11 Heinrich J. Voelk

This paper summarizes the status of very high-energy (VHE) astronomy, as of early 2003. It concentrates on observations made by gamma-ray telescopes operating at energies above 10 GeV. This field is an exciting one to be working in, with a…

Astrophysics · Physics 2007-05-23 Rene A. Ong

Atmospheric Cerenkov Telescopes, including HESS and MAGIC, have detected a spectrum of gamma-rays from the galactic center region which extends from $\sim$200 GeV or lower, to at least $\sim$10 TeV. Although the source of this radiation is…

Astrophysics · Physics 2008-11-26 Gabrijela Zaharijas , Dan Hooper

The diffuse gamma ray emission from astrophysical backgrounds in our Galaxy and the signal due to the annihilation or decay of Dark Matter (DM) in the Galactic Halo are expected to have a substantially different morphology and spectral…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Gabrijela Zaharijas , Alessandro Cuoco , Zhaoyu Yang , Jan Conrad

With the unequalled INTEGRAL observatory, ESA has provided a unique tool to the astronomical community that has made Europe the world leader in the field of gamma-ray astronomy. INTEGRAL provides an unprecedented survey of the soft…

Astrophysics · Physics 2008-11-26 Jürgen Knödlseder

Flares close to the solar limb, where the footpoints are occulted, can reveal the spectrum and structure of the coronal loop-top source in X-rays. We aim at studying the properties of the corresponding energetic electrons near their…

In the first three years of operation STIS obtained slitless spectra of approximately 2500 fields in parallel to prime HST observations as part of the STIS Parallel Survey (SPS). The archive contains almost 300 fields at high galactic…

In this paper, we analyze hard X-ray spikes observed by RHESSI to understand their temporal, spectral, and spatial properties. A recently developed demodulation code was applied to hard X-ray light curves in several energy bands observed by…

Solar and Stellar Astrophysics · Physics 2015-06-11 J. Qiu , J. X. Cheng , G. J. Hurford , Y. Xu , H. Wang

We illustrate a method for estimating the vertical position of the Sun above the Galactic plane by $\gamma$-ray observations. Photons of $\gamma$-ray wavelengths are particularly well suited for geometrical and kinematic studies of the…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Thomas Siegert

On 2019 October 25, the Fermi-Large Area Telescope observed the first gamma-ray flare from the radio-loud narrow-line Seyfert 1 (NLSy 1) galaxy PKS 2004$-$447 ($z=0.24$). We report on follow-up observations in the radio, optical-UV, and…

The shell-type supernova remnant RX J0852.0-4622 was detected in 2004 and re-observed between December 2004 and May 2005 with the High Energy Stereoscopic System (H.E.S.S.), an array of four Imaging Cherenkov Telescopes located in Namibia…

With its excellent sensitivity, large field of view, broad energy coverage, and good per-photon angular resolution, the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope satellite provides us with an unprecedented view of the…

High Energy Astrophysical Phenomena · Physics 2022-03-02 Jürgen Knödlseder