Results 21 to 30 of about 5,393 (182)

Effect of Ephemeris on Pulsar Timing and Navigation Accuracy Based on X-ray Pulsar Navigation-I Data

Universe, 2022
Solar system ephemeris is very important for pulsar timing and navigation. In order to explore the effect of different precision ephemerides on X-ray pulsar timing and navigation, the differences between timing and navigation results with four JPL ...
Yongtao Deng, Shuanggen Jin
doaj   +1 more source

Cherenkov Telescope Array Observatory: Die Zukunft der Gammaastronomie

Physik in unserer Zeit, Volume 57, Issue 1, Page 10-18, January 2026.
Im Jahr 1989 hat das Wipple‐Observatorium die erste Quelle hochenergetischer Gammastrahlung entdeckt. 2002 waren dann sechs Quellen bekannt, 2024 schon mehr als 300. Und das ist immer noch lediglich die Spitze des Eisbergs in der jungen Geschichte der Gammaastronomie.
Daniela Hadasch, Daniel Mazin
wiley   +1 more source

XMM-Newton and Chandra Observations of the Candidate Fermi-LAT Pulsar 4FGL J1015.5-6030

The Astrophysical Journal, 2023
4FGL J1015.5-6030 is an unidentified Fermi-LAT source hosting a bright, extended X-ray source whose X-ray spectrum is consistent with that of a young pulsar, yet no pulsations have been found.
Jeremy Hare, Oleg Kargaltsev, George Younes, George G. Pavlov, Igor Volkov   +4 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

Phase-resolved Deadtime of the Crab Pulsar Using IXPE Data

The Astrophysical Journal
After receiving an X-ray photon, an X-ray detector is not operational for a duration known as deadtime. It is detector specific and its effect on the data depends upon the luminosity of the source.
M. Vivekanand
doaj   +1 more source

Swinging between rotation and accretion power in a binary millisecond pulsar

EPJ Web of Conferences, 2014
We present the discovery of IGR J18245–2452, the first millisecond pulsar observed to swing between a rotation-powered, radio pulsar state, and an accretion-powered X-ray pulsar state [31]. This transitional source represents the most convincing proof of
Papitto A., Ferrigno C., Bozzo E., Rea N.   +3 more
doaj   +1 more source

Resonant Effect for Breit–Wheeler Process in the Field of an X-ray Pulsar

Universe, 2020
The resonant process of the creation of an ultrarelativistic electron–positron pair by two hard gamma quanta in the field of an X-ray pulsar (the Breit–Wheeler process modified by an external field) was theoretically studied.
Vitalii D. Serov, Sergei P. Roshchupkin, Victor V. Dubov   +2 more
doaj   +1 more source

A new green synthesis approach using sodium palmitate in the synthesis of a Ni/Al2O3 catalyst for CO2 methanation

The Canadian Journal of Chemical Engineering, Volume 103, Issue 11, Page 5173-5188, November 2025.
Abstract CO2 methanation with Ni/Al2O3 catalysts is a key technology for converting CO2 emissions into sustainable methane. However, conventional impregnation synthesis often results in poor nickel dispersion and in the emission of gaseous NOx species.
Anderson F. C. Silva, Eduardo L. de Barros Neto, Bruna R. de Vasconcelos   +2 more
wiley   +1 more source

Beyond tumour suppression: cGAS‐STING pathway in urologic malignancies: Context‐dependent duality and therapeutic implications

Clinical and Translational Medicine, Volume 15, Issue 11, November 2025.
The context‐dependent duality of cGAS–STING signalling in urologic tumours is revealed. Targeting the STING pathway, in combination with immunotherapies and gene therapies, enhances the anti‐tumour response. Sex hormone differences in urological malignancies are correlated with the cGAS–STING pathway.
Qi Wei, Kui Zhao, Yifan Wu, Wenhui Wu, Na Hao   +4 more
wiley   +1 more source

Electron Density Structure Measurements With Scattered Intense Laser Beam

Contributions to Plasma Physics, Volume 65, Issue 10, November 2025.
ABSTRACT Short‐pulse intense lasers have the potential to model extreme astrophysical environments in laboratories. Although there are diagnostics for energetic electrons and ions resulting from laser‐plasma interactions, the diagnostics to measure velocity distribution functions at the interaction region of the laser and plasma are limited.
K. Sakai, K. Himeno, S. J. Tanaka, T. Asai, T. Minami, Y. Abe, F. Nikaido, K. Kuramoto, M. Kanasaki, H. Kiriyama, A. Kon, K. Kondo, N. Nakanii, W. Y. Woon, C. M. Chu, K. T. Wu, C. S. Jao, Y. L. Liu, T. A. Pikuz, H. Kohri, A. O. Tokiyasu, S. Isayama, H. S. Kumar, K. Tomita, Y. Fukuda, Y. Kuramitsu   +25 more
wiley   +1 more source