Results 61 to 70 of about 19,895 (210)

First Time‐Resolved Leader Spectra Associated With a Downward Terrestrial Gamma‐Ray Flash Detected at the Telescope Array Surface Detector

Journal of Geophysical Research: Atmospheres, Volume 129, Issue 24, 28 December 2024.
Abstract Optical emissions associated with Terrestrial Gamma ray Flashes (TGFs) have recently become important subjects in space‐based and ground‐based observations as they can help us understand how TGFs are produced during thunderstorms. In this paper, we present the first time‐resolved leader spectra of the optical component associated with a ...
N. Kieu, R. U. Abbasi, M. M. F. Saba, J. W. Belz, P. R. Krehbiel, M. A. Stanley, F. J. Gordillo‐Vazquez, M. Passas‐Varo, T. Warner, W. Rison, D. Rodeheffer, D. R. da Silva, D. Mazzucco, T. Knight, I. T. Cruz, J. Remington, J. Mazich, R. LeVon, K. Smout, A. Petrizze, T. Abu‐Zayyad, M. Allen, D. R. Bergman, I. Buckland, W. Campbell, B. G. Cheon, K. Endo, A. Fedynitch, T. Fujii, K. Fujisue, K. Fujita, M. Fukushima, G. Furlich, Z. Gerber, N. Globus, W. Hanlon, N. Hayashida, H. He, K. Hibino, R. Higuchi, D. Ikeda, T. Ishii, D. Ivanov, S. Jeong, C. C. H. Jui, K. Kadota, F. Kakimoto, O. Kalashev, K. Kasahara, Y. Kawachi, K. Kawata, I. Kharuk, E. Kido, H. B. Kim, JiHee Kim, JiHyun Kim, S. W. Kim, R. Kobo, I. Komae, K. Komatsu, K. Komori, C. Koyama, M. Kudenko, M. Kuroiwa, Y. Kusumori, M. Kuznetsov, Y. J. Kwon, K. H. Lee, M. J. Lee, B. Lubsandorzhiev, J. P. Lundquist, A. Matsuzawa, J. A. Mathews, J. N. Matthews, K. Mizuno, M. Mori, M. Murakami, S. Nagataki, M. Nakahara, T. Nakamura, T. Nakayama, Y. Nakayama, T. Nonaka, S. Ogio, H. Ohoka, N. Okazaki, M. Onishi, A. Oshima, H. Oshima, S. Ozawa, I. H. Park, K. Y. Park, M. Potts, M. Przybylak, M. S. Pshirkov, C. Rott, G. I. Rubtsov, D. Ryu, H. Sagawa, N. Sakaki, R. Sakamoto, T. Sako, N. Sakurai, S. Sakurai, D. Sato, S. Sato, K. Sekino, T. Shibata, J. Shikita, H. Shimodaira, B. K. Shin, H. S. Shin, K. Shinozaki, J. D. Smith, P. Sokolsky, B. T. Stokes, T. A. Stroman, Y. Takagi, K. Takahashi, M. Takeda, R. Takeishi, A. Taketa, M. Takita, Y. Tameda, K. Tanaka, M. Tanaka, S. B. Thomas, G. B. Thomson, P. Tinyakov, I. Tkachev, T. Tomida, S. Troitsky, Y. Tsunesada, S. Udo, F. Urban, I. A. Vaiman, M. Vrábel, D. Warren, K. Yamazaki, Y. Zhezher, Z. Zundel, J. Zvirzdin   +141 more
wiley   +1 more source

Long-Term Monitoring of Blazar PKS 0208-512: A Change of γ-Ray Baseline Activity from EGRET to Fermi Era

Universe, 2022
The blazar PKS 0208-512 was in the lowest γ-ray brightness state during the initial 10 years of observations with the Fermi Gamma-ray Space Telescope (Fermi), which was an order of magnitude lower than its flux state during the EGRET era (1991–2000). The
Krishna Mohana Ammenadka, Debbijoy Bhattacharya, Subir Bhattacharyya, Nilay Bhatt, Chelliah Subramonian Stalin   +4 more
doaj   +1 more source

Fermi-LAT upper limits on gamma-ray emission from colliding wind binaries

, 2012
Context: Colliding wind binaries (CWBs) are thought to give rise to a plethora of physical processes including acceleration and interaction of relativistic particles. Observation of synchrotron radiation in the radio band confirms there is a relativistic
Egberts, K., Reimer, A., Reimer, O., Werner, M.   +3 more
core   +1 more source

Solving the Puzzle of the Carbonic Acid Vibrational Spectrum – an Anharmonic Story

ChemPhysChem, Volume 25, Issue 22, November 18, 2024.
The harmonic picture is the basic approximation that allows the prediction of vibrational spectra. However, reality is neither decoupled nor harmonic. This can lead to problems in notation and the assignment of individual bands. Taking anharmonicity and mode coupling into account allows a drastic improvement in spectral clarity.
Jonas Schlagin, Dennis F. Dinu, Jürgen Bernard, Thomas Loerting, Hinrich Grothe, Klaus R. Liedl   +5 more
wiley   +1 more source

The Statistical Analysis of GeV Spectral Breaks in Bright Gamma-Ray Flat-spectrum Radio Quasars

The Astrophysical Journal Supplement Series
We present the statistical results of GeV spectral breaks of bright gamma-ray flat-spectrum radio quasars (FSRQs) in the energy range of 0.1–10 GeV based on New Pass 8 data of the Large Area Telescope on board Fermi Gamma-Ray Space Telescope.
K. R. Zhu, J. M. Chen, L. Zhang
doaj   +1 more source

Highlights of GeV Gamma-Ray Astronomy [PDF]

, 2010
Because high-energy gamma rays are primarily produced by high-energy particle interactions, the gamma-ray survey of the sky by the Fermi Gamma-ray Space Telescope offers a view of sites of cosmic ray production and interactions. Gamma-ray bursts, pulsars,
Thompson, David J.
core   +1 more source

TANAMI - Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry

, 2010
We present a summary of the observation strategy of TANAMI (Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry), a monitoring program to study the parsec-scale structure and dynamics of relativistic jets in active galactic nuclei (
A. K. Tzioumis, A. L. Fey, C. Müller, C. Plötz, D. J. Thompson, D. L. Jauncey, E. Ros, G. B. Taylor, G. Tosti, H. Hase, J. A. Zensus, J. E. J. Lovell, J. F. H. Quick, J. Wilms, K. J. Johnston, L. Fuhrmann, M. Böck, M. Kadler, M. Lister, M. S. Dutka, P. G. Edwards, R. A. Gaume, R. Booth, R. Ojha, S. Horiuchi, S. J. Tingay, U. Katz   +26 more
core   +1 more source

SU(2)X vector DM and Galactic Center gamma-ray excess

Physics Letters B, 2015
An unbroken Z3 symmetry remains when a local SU(2)X symmetry is broken spontaneously by a quadruplet. The gauge boson χμ(χ¯μ) carries the dark charge and is the candidate of dark matter (DM).
Chuan-Hung Chen, Takaaki Nomura
doaj   +1 more source

Lessons from the apparent peculiar nature of the star TYC 6544‐3483‐1

Astronomische Nachrichten, Volume 345, Issue 4, May 2024.
Abstract We report a radio and optical study of the star TYC 6544‐3483‐1 originally selected as a follow‐up target in the course of our efforts to cross‐identify Galactic high‐energy sources. The star by itself finally turned out to be a very ordinary main‐sequence star despite the initial expectations that apparently pointed to the contrary.
Josep Martí, Pedro L. Luque‐Escamilla, Benito Marcote, Daniel del Ser, Gustavo E. Romero, Cintia S. Peri   +5 more
wiley   +1 more source

Discovery of an Extended γ-Ray Emission around the Supernova Remnant Candidate Associated with PSR J0837–2454

The Astrophysical Journal, 2023
Motivated by the recent discovery of a low-surface-brightness diffuse emission, a supernova remnant (SNR) candidate, surrounding the young pulsar PSR J0837–2454, we carry out a likelihood analysis of the γ -ray data obtained by the Fermi Gamma-ray Space ...
Pengfei Zhang, Yuliang Xin
doaj   +1 more source