Results 91 to 100 of about 74,904 (235)

Gamma-Ray Astronomy

open access: yes, 2008
In this paper, I present a summary of the status of γ-ray astronomy in the very high energy band (E > 50GeV), as of early 2007. It covers a selection of results obtained from observations made by ground-based detectors using the atmospheric Cherenkov or air shower techniques, together with short descriptions of some of the present and future ...
openaire   +2 more sources

On optimisation of Paganin's method for propagation‐based X‐ray phase‐contrast imaging and tomography

open access: yesJournal of Microscopy, EarlyView.
Abstract Paganin's method for image reconstruction in propagation‐based phase‐contrast X‐ray imaging and tomography has enjoyed broad acceptance in recent years, with over one thousand publications citing its use. The present paper discusses approaches to optimisation of the method with respect to simple image quality metrics, such as signal‐to‐noise ...
Timur E. Gureyev   +3 more
wiley   +1 more source

ESA INTEGRAL and Cataclysmic Variables

open access: yesOdessa Astronomical Publications, 2017
The satellite INTEGRAL is ESA project operating since January 2003. It is dedicated to high energy astronomy. INTEGRAL is able to detect and perform astrometry, photometry and spectroscopy of sources from X-ray to gamma-ray regime (nominal range of ...
Jan Strobl   +4 more
doaj   +1 more source

New knowledge about shock events that affected the L‐chondrite parent body from two heavily shocked L6 meteorite finds

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract We report new results from a study of shock‐related features in the L6 ordinary chondrites Northwest Africa (NWA) 4672 and NWA 12841. Our observations confirm the occurrence of eight high‐pressure (HP) minerals in each meteorite, namely, ringwoodite, majorite, akimotoite, wadsleyite, albitic jadeite, lingunite, tuite, and xieite.
I. Baziotis   +5 more
wiley   +1 more source

Expectation for the Hard X-Ray and Gamma-Ray Emission from Pair-instability Supernovae

open access: yesThe Astrophysical Journal
Pair-instability supernovae (PISNe) are predicted thermonuclear explosions of massive stars with helium core masses exceeding ∼65 M _⊙ , and they synthesize substantial amounts of radioactive ^56 Ni ( M ( ^56 Ni) ∼ 60 M _⊙ in extreme cases).
Ryo Sawada
doaj   +1 more source

Ground-Based Gamma Ray Astronomy [PDF]

open access: yesBrazilian Journal of Physics, 2014
This paper is the write-up of a rapporteur talk given by the author at the 33rd International Cosmic Ray Conference in Rio de Janeiro, Brazil, in 2013. It attempts to summarize results and developments in ground-based gamma-ray observations and instrumentation from among the $\sim300$ submissions to the gamma-ray sessions of the meeting.
openaire   +2 more sources

Araguainha Dome, Brazil: A polygonal impact structure due to a complex pre‐impact regional structural framework

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract We investigated the structural framework of the north–northwestern Paraná Basin in Brazil to test whether the pre‐impact structures in this region may have had any influence on the first‐order formation and morphostructure of the Araguainha impact structure (AIS).
Renato B. Bernardes   +5 more
wiley   +1 more source

Multi-wavelength studies of the gamma-ray pulsar PSR J1907+0602

open access: yes, 2012
PSR J1907+0602 is a radio-faint, 107-ms GeV gamma-ray pulsar that was discovered with the Fermi LAT in a blind pulsar search. PSR J1907+0602 is located near the bright, extended TeV gamma-ray source MGRO J1908+06 which may be an associated pulsar wind ...
Pandel, Dirk, Scott, Robert
core   +1 more source

Thermal histories of El Médano 300 (EM 300) and Northwest Africa 8155 (NWA 8155): Implications for the diversity of IAB‐ungrouped iron meteorites and their parent bodies

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract This study provides the first petrographic, crystallographic, and chemical comparison between El Médano 300 (EM 300) and Northwest Africa 8155 (NWA 8155), two particular IAB‐ungrouped iron meteorites. Both contain exceptionally large graphite nodules and “flowers”, providing unique insights into carbon behavior in metallic melts and cooling ...
L. Perez   +8 more
wiley   +1 more source

The origin of cosmic rays and TeV gamma-ray astronomy

open access: yesEPJ Web of Conferences, 2013
Cosmic rays are accelerated to high energies in Galactic and extragalactic objects like Supernova remnants (SNR) and active galactic nuclei (AGN). How these accelerators work and how efficient they accelerate different types of particles to energies of ...
Maier Gernot
doaj   +1 more source

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