Results 51 to 60 of about 736 (212)

The ALPACA experiment: The project of the first sub-PeV gamma-ray observation in the southern sky

SciPost Physics Proceedings, 2023
The ALPACA experiment is a project aiming to observe sub-PeV gamma rays for the first time in the southern hemisphere. The main goal of ALPACA is to identify PeVatrons, the accelerators of Galactic PeV cosmic rays, by observing sub-PeV pion-decay gamma ...
Teruyoshi Kawashima for the ALPACA Collaboration
doaj   +1 more source

Relevance of Murchison Widefield Array Interplanetary Scintillation Observations to Heliospheric Transient Catalogs

Space Weather, Volume 23, Issue 12, December 2025.
Abstract We have conducted a comprehensive comparison of interplanetary scintillation (IPS) observations taken by the Murchison Widefield Array (MWA) with several heliospheric transient event catalogs, over a time period of 7 months during solar minimum.
A. Waszewski, J. S. Morgan, M. C. M. Cheung, R. Ekers, E. Samara, S. Majumdar, R. Chhetri, N. D. R. Bhat, M. Johnston‐Hollitt   +8 more
wiley   +1 more source

Rapid interstellar scintillation of quasar PKS 1257-326 [PDF]

, 2005
PKS 1257-326 is one of three quasars known to show unusually large and rapid, intra-hour intensity variations, as a result of scintillation in the turbulent Galactic interstellar medium.
Macquart, Jean-Pierre, Jauncey, David L., Lovell, James E. J., Kedziora-Chudczer, Lucyna, Bignall, Hayley E., Tzioumis, Anastasios K.   +5 more
core   +2 more sources

A Cyclic Spectroscopy Scintillation Study of PSR B1937+21. I. Demonstration of Improved Scintillometry

The Astrophysical Journal
We use cyclic spectroscopy to perform high-frequency resolution analyses of multihour baseband Arecibo observations of the millisecond pulsar PSR B1937+21.
Jacob E. Turner, Timothy Dolch, James M. Cordes, Stella K. Ocker, Daniel R. Stinebring, Shami Chatterjee, Maura A. McLaughlin, Victoria E. Catlett, Cody Jessup, Nathaniel Jones, Christopher Scheithauer   +10 more
doaj   +1 more source

New Arabic Records From Cairo on Supernovae 1181 and 1006

Astronomische Nachrichten, Volume 346, Issue 9, November 2025.
ABSTRACT The remnant of the historical supernova SN 1181 is under discussion: While the previously suggested G130.7+3.1 (3C58) appears too old (3000–5000 year), the unusual star IRAS00500+6713 with a surrounding nebula (Pa‐30) has an expansion age not inconsistent with a SN Iax explosion in ad 1181 under the assumption that neither acceleration nor ...
J. G. Fischer, H. Halm, R. Neuhäuser, D. L. Neuhäuser   +3 more
wiley   +1 more source

Correlation Patterns of Muon Flux With Vertical Atmospheric Profiles: Insights From Monte Carlo Simulations

Journal of Geophysical Research: Space Physics, Volume 130, Issue 11, November 2025.
Abstract The production, attenuation, and absorption of secondary cosmic rays (SCR) are influenced by atmospheric parameters such as air pressure and temperature. To reliably correlate SCR flux measurements with atmospheric ionization driven by energetic particle precipitation, these dependencies must be quantified.
A. Al‐Qaaod, V. Pierrard, A. Winant, U. Stolzenberg, I. Ambrozova, M. Sommer, J. Slegl, J. Solc, A. Gkikoudi, A. G. Georgakilas, A. Papayannis, F. S. Krasniqi   +11 more
wiley   +1 more source

Interstellar scintillation, AGN physics and the SKA [PDF]

, 2008
A large fraction of compact, extragalactic radio sources exhibit rapid variability at centimetre wavelengths as their radio emission is scattered by electron density fluctuations in the interstellar medium of the Galaxy.
Rickett, B.J., Macquart, Jean-Pierre, Senkbeil, C., Kedziora-Chudczer, L., Dutka, M., Bignall, Hayley, Jauncey, J., Ojha, Roopesh, Lovell, J, Pursimo, T., Shabala, S.   +10 more
core  

Pulsar Scintillation through Thick and Thin: Bow Shocks, Bubbles, and the Broader Interstellar Medium [PDF]

, 2023
Observations of pulsar scintillation are among the few astrophysical probes of very small-scale ($\lesssim$ au) phenomena in the interstellar medium (ISM).
Chatterjee, S., McKee, J. W., Reardon, D. J., Cordes, J. M., Stinebring, D. R., Pelgrims, V., Dolch, T., Giannakopoulos, C., Ocker, S. K.   +8 more
core   +1 more source

Single Epoch Measurements of Dispersion Measure Gradients towards PSR B0834+06

The Astrophysical Journal
Understanding the evolution of pulsar dispersion measures is vital to high-precision timing experiments, as well as astrometric experiments to determine pulsar positions and proper motions.
Daniel Baker, Ue-Li Pen
doaj   +1 more source

Interstellar Scintillations of Polarization of Compact Sources

The Astrophysical Journal, 2000
We demostrate that the measurement of fluctuations of polarization due to the galactic interstellar scintillations may be used to study the structure of the radiation field at compact radio sources. We develop a mathematical formalism and demonstrate it on a simple analytical model in which the scale of the polarization variation through the source is ...
openaire   +3 more sources