Results 101 to 110 of about 37,593 (223)

MHD simulations of the solar photosphere

, 2012
We briefly review the observations of the solar photosphere and pinpoint some open questions related to the magnetohydrodynamics of this layer of the Sun.
Rieutord, M., Rincon, F., Roudier, T.
core   +1 more source

Neutrino Constraints and Detection Prospects from Gamma-Ray Bursts with Different Jet Compositions

The Astrophysical Journal
The prompt emission mechanism of gamma-ray bursts (GRBs) is a long-standing open question, and GRBs have been considered as potential sources of high-energy neutrinos. Despite many years of search for the neutrino events associated with GRBs from IceCube,
Yang-Dong-Jun Ou, Hou-Jun Lü, Xue-Zhao Chang, Xiao-Xuan Liu, En-Wei Liang   +4 more
doaj   +1 more source

Multi-height probing of horizontal flows in the solar photosphere

Astronomy & Astrophysics
Context. Optical flow methods aim to infer horizontal (transverse, in the general case) velocities in the solar atmosphere from the temporal changes in maps of physical quantities, such as intensity or magnetic field.
Kostić T., Milić I., Rempel M., Welsch B., Kazachenko M., Asensio Ramos A., Tremblay B.   +6 more
doaj   +1 more source

Unstable GRB photospheres and electron-positron annihilation lines

, 2007
We propose an emission mechanism of prompt gamma-ray bursts (GRBs) that can reproduce the observed non-thermal spectra with high radiative efficiencies, >50%. Internal dissipation below a photosphere can create a radiation-dominated thermal fireball.
Kenji Toma, Kohta Murase, Kunihito Ioka, Ramirez-Ruiz E., Shigehiro Nagataki, Svensson R., Takashi Nakamura, Thompson C.   +7 more
core   +1 more source

Derivation and Application of a Scaling between Hinode/SP and SDO/HMI Vector Magnetic Fields to Improve Magnetic Field Extrapolations

The Astrophysical Journal
Full-disk measurements of the solar magnetic field by the Helioseismic and Magnetic Imager (HMI) are often used for magnetic field extrapolations, but its limited spatial and spectral resolution can lead to significant errors.
C. Beck, A. Prasad, Q. Hu, M. S. Yalim, S. Gosain, D. Prasad Choudhary   +5 more
doaj   +1 more source

Chromospheric and photospheric properties of sunspots as inferred from Stokes inversions under magnetohydrostatic and non-local thermodynamic equilibrium

Astronomy & Astrophysics
Context. Sunspots represent a key feature in the solar atmosphere to explore how magnetic fields interact with plasma flows, exhibiting large variations in physical parameters over very small spatial scales (< 100 km), and sometimes featuring dynamic ...
Vicente Arévalo A., Borrero J. M., Milić I., Pastor Yabar A., Kontogiannis I., Pietrow A. G. M.   +5 more
doaj   +1 more source

Magnetic Flux Emergence and Solar Eruptions in Partially Ionized Plasmas

The Astrophysical Journal
We have performed 3D MHD simulations to study the effect of partial ionization in the process of magnetic flux emergence in the Sun. In fact, we continue previous work, and we now focus (1) on the emergence of the magnetic fields above the solar ...
Georgios Chouliaras, V. Archontis
doaj   +1 more source

Assessment of DKIST/VTF capabilities for the detection of local acoustic source wavefronts

Frontiers in Astronomy and Space Sciences
IntroductionRecent studies have demonstrated that temporal filtering can successfully identify local acoustic source wavefronts in radiative magnetohydrodynamic simulations of the solar photosphere.
Corinne Morrell, Corinne Morrell, Mark P. Rast, Mark P. Rast, Shah Mohammad Bahauddin, Shah Mohammad Bahauddin, Ivan Milić   +6 more
doaj   +1 more source

Formation of a Magnetic Flux Rope prior to the Eruption: Insight from a Radiative MHD Simulation of Active Region Emergence

The Astrophysical Journal Letters
Magnetic flux ropes are fundamental magnetic structures in solar eruptions, whose formation is generally attributed to: (1) the emergence of subsurface flux tubes; or (2) flux cancellation driven by photospheric horizontal flows and magnetic reconnection.
Can Wang, Takaaki Yokoyama, Feng Chen, Chen Xing, Mingde Ding, Zekun Lu   +5 more
doaj   +1 more source

Identifying Coronal Sources of L1 Solar Wind Disturbances Using the Fisk Heliospheric Magnetic Field and Potential Field Extrapolations during Three Solar Minima

The Astrophysical Journal
The solar minima between solar cycles 22–23, 23–24, and 24–25 are the best observed minima on record. In situ solar wind and interplanetary magnetic field measurements by the Wind and ACE spacecraft at L1 with 1 hr cadence are explored using wavelet ...
P. J. Steyn, D. Johnson, G. J. J. Botha, S. Régnier   +3 more
doaj   +1 more source