Results 101 to 110 of about 74,658 (229)

Gamma-ray signatures of cosmic ray acceleration, propagation, and confinement in the era of CTA

, 2012
Galactic cosmic rays are commonly believed to be accelerated at supernova remnants via diffusive shock acceleration. Despite the popularity of this idea, a conclusive proof for its validity is still missing.
A. Bamba, A. Marcowith, Acharya B. S., Actis M., Aghajani T., CTA Consortium, D. Hadasch, D. F. Torres, E. Bissaldi, E. d. Cea, E. d. Ona, et al., F. Acero, F. Volpe, G. Pedaletti, M. Renaud, O. Reimer, S. Casanova, S. Gabici, Y. Gallant   +19 more
core   +3 more sources

HRTEM Imaging and Mechanistic Insights Into Carbon Nanotube Nucleation and Growth on Fe Nanocatalysts in a Thermal Plasma

Small Methods, EarlyView.
Carbon nanotubes (CNTs) were successfully debundled from Tuball soots produced using iron nanocatalysts in arc discharge thermal plasma and distributed on monolayer graphene for HRTEM imaging for mechanistic insights into CNT synthesis. Zigzag single‐wall or double‐wall CNTs were identified.
Hengfei Gu, Stanislav Musikhin, Guangming Cheng, Nan Yao, Yevgeny Raitses, Bruce E. Koel   +5 more
wiley   +1 more source

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

The 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

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

Journal 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, David M. Paganin, Ashkan Pakzad, Harry M. Quiney   +3 more
wiley   +1 more source

The origin of cosmic rays and TeV gamma-ray astronomy

EPJ 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

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

Meteoritics &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, L. Ferrière, C. Ma, J. Hu, D. Palles, P. D. Asimow   +5 more
wiley   +1 more source

CI chondrite Oued Chebeika 002 links asteroids Bennu and Ryugu to common parent body

Meteoritics &Planetary Science, EarlyView.
Abstract CI chondrites are a compositionally primitive group of meteorites that have undergone extensive aqueous alteration, providing insights into the evolution of primitive planetesimals. Oued Chebeika 002 is the most pristine CI chondrite to date.
Megan Broussard, Katharina Lodders, Paul K. Carpenter, Piers Koefoed, Karen Ziegler, Kunihiko Nishiizumi, Marc W. Caffee, Laurence A. J. Garvie, Ryan C. Ogliore, Anthony J. Irving, Bradley L. Jolliff, Kun Wang   +11 more
wiley   +1 more source

GRB 250704B: An Off-axis Short GRB with a Long-lived Afterglow Plateau

The Astrophysical Journal Letters
We present a detailed multiwavelength afterglow study of the short gamma-ray burst (GRB) GRB 250704B, extensively monitored in optical and near-infrared bands.
Vishwajeet Swain, Tomás Ahumada, Sameer K. Patil, Yogesh Wagh, Varun Bhalerao, Ehud Nakar, Mansi Kasliwal, Xander J. Hall, Malte Busmann, Utkarsh Pathak, Shreya Anand, Viraj Karambelkar, Igor Andreoni, G. C. Anupama, Anuraag Arya, Arvind Balasubramanian, Sudhanshu Barway, Jonathan Carney, Michael Coughlin, D. Eappachen, James Freeburn, Daniel Gruen, Tanishk Mohan, Brendan O’Connor, Antonella Palmese, D. K. Sahu, Aditya Pawan Saikia, Nikhil Sarin, Gokul Srinivasaragavan, Hitesh Tanenia   +29 more
doaj   +1 more source

Ryugu Reference Project: Recommendations from the Measurement Definition Team

Meteoritics &Planetary Science, EarlyView.
Abstract Sample return missions play a significant role in planetary science by providing pristine extraterrestrial materials. JAXA's Hayabusa2 and NASA's OSIRIS‐REx missions have returned samples from the C‐type asteroids Ryugu and Bennu, respectively. The chemical and mineralogical compositions of these samples closely resemble those of CI chondrites,
Tetsuya Yokoyama, Guillaume Avice, Henner Busemann, Nicolas Dauphas, Daniel P. Glavin, Ashley J. King, Thorsten Kleine, Katharina Lodders, Frederic Moynier, Maria Schönbächler, Yoshinori Takano, Kun Wang, Hikaru Yabuta, Yuma Enokido, Ryota Fukai, Shogo Tachibana, Tomohiro Usui   +16 more
wiley   +1 more source

Scientific Highlights from Observations of Active Galactic Nuclei with the MAGIC Telescope

, 2008
Since 2004, the MAGIC gamma-ray telescope has newly discovered 6 TeV blazars. The total set of 13 MAGIC-detected active galactic nuclei includes well-studied objects at other wavelengths like Markarian 501 and the giant radio galaxy M87, but also the ...
Felix A. Aharonian, Frank Rieger, null null, Robert Wagner, Werner Hofmann   +4 more
core   +1 more source