Results 51 to 60 of about 1,371 (185)
Quasi-thermal Photosphere Emission from Structured Jets of Gamma-Ray Bursts
The Astrophysical JournalThe prompt emission of gamma-ray bursts (GRBs) is supposed to be released from the relativistic jet launched from the central engine. Apart from the nonthermal nature of spectra in the majority of GRBs, there is evidence for the presence of quasi-thermal
Ding-Fang Hu +4 more
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On the Freeze‐In Distance of Solar Wind Fluid Entropy Variability in the Corona
Journal of Geophysical Research: Space Physics, Volume 131, Issue 3, March 2026.Abstract The strong correlation between solar wind entropy and the frozen‐in ion charge state ratio O7+/O6+ ${\mathrm{O}}^{7+}/{\mathrm{O}}^{6+}$ indicates that entropy variability on timescales of hours or longer is preserved from its solar source. This prompts the question: where in the solar atmosphere does this entropy variability come from, and at
Aidan J. Nakhleh +3 more
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The Relationship between Kinetic and Magnetic Helicity in Solar Active Regions
The Astrophysical JournalUsing Helioseismic and Magnetic Imager/Solar Dynamics Observatory data, we search for a relationship between kinetic helicity and magnetic helicity in solar active regions (ARs) using a sample of 62 ARs from 2010 May to 2015 May.
Yang Liu +5 more
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Subphotospheric Emission from Short Gamma-Ray Bursts: Protons Mold the Multimessenger Signals
The Astrophysical Journal LettersThe origin of the observed Band-like photon spectrum in short gamma-ray bursts (sGRBs) is a long-standing mystery. We carry out the first general relativistic magnetohydrodynamic simulation of an sGRB jet with initial magnetization σ _0 = 150 in ...
Annika Rudolph +2 more
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The Striated Solar Photosphere Observed at Resolution
The Astrophysical Journal LettersStriated granular edges observed in the solar photosphere represent one of the smallest-scale phenomena on the Sun. They arise from the interaction of strongly coupled hydrodynamic, magnetic, and radiative properties of the plasma.
David Kuridze +7 more
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PHYSICS OF NONDISSIPATIVE ULTRARELATIVISTIC PHOTOSPHERES [PDF]
International Journal of Modern Physics D, 2014 Recent observations, especially by the Fermi satellite, point out the importance of the thermal component in GRB spectra. This fact revives strong interest in photospheric emission from relativistic outflows. Early studies already suggested that the observed spectrum of photospheric emission from relativistically moving objects differs in shape from ...
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Thermal Bifurcation Of the Outer Photosphere [PDF]
Symposium - International Astronomical Union, 1990 The degree of thermal heterogeneity at the base of the solar chromosphere is substantially beyond that simulated in the best-available multi-component models; casting serious doubts on inferences drawn from them.
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Optically Thick Jet Base and Explanation of Edge Brightening in Active Galactic Nucleus Jets
The Astrophysical JournalThe jet cores in active galactic nuclei (AGNs) are resolved and found to harbor an edge-brightened structure where the jet base appears extended at the sides compared to its propagation axis. This peculiar phenomenon invites various explanations. We show
Mukesh Kumar Vyas, Asaf Pe’er
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Multiwavelength Emission of Gamma-Ray Burst Prompt Phase. II. Spectral Polarimetry
The Astrophysical JournalPolarization spectra were predicted within the photosphere model. To seek more clues to distinguish between the models, both the time-resolved and time-integrated polarization spectra from optical band to MeV gamma-rays of the magnetic reconnection model
Jia-Sheng Li, Mi-Xiang Lan
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Astronomy & AstrophysicsContext. Space weather and its potential negative consequences for life on Earth have received increasing scientific attention in recent decades. In particular, predicting the onset of coronal mass ejections (CMEs) has become important from a security ...
Furuseth S. V., Aulanier G.
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