Results 61 to 70 of about 1,371 (185)
The Astrophysical JournalThe time-integrated polarization degree (PD) in the prompt optical band of a gamma-ray burst (GRB) was predicted to be less than 20%, while the time-resolved one can reach as high as 75% in the photosphere model.
Jia-Sheng Li +2 more
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Deconstructing Photospheric Spectral Lines in Solar and Stellar Flares
The Astrophysical JournalDuring solar flares, spectral lines formed in the photosphere have been shown to exhibit changes to their profiles despite the challenges of energy transfer to these depths.
Aaron J. Monson +2 more
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Observational Evidence of Shallow Origins for the Magnetic Fields of Solar Cycles
Frontiers in Astronomy and Space Sciences, 2018 Observational evidence for the origin of active region magnetic fields has been sought from published information on extended solar cycles, statistical distributions of active regions and ephemeral regions, helioseismology results, positional ...
Sara F. Martin
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On Photospheric Flows and Chromospheric Corks
, 1994 Proper motions of granules are measured by local correlation tracking on a 4.5 h image sequence obtained with the Swedish Vacuum Tower Telescope at La Palma. A 2 arcsec spatial low-pass filter is applied to obtain meso-scale flow patterns. We find that their characteristic lifetime (1/e value) has a lower limit of five to six hours.
Brandt, P.N. +3 more
openaire +2 more sources
Optically Thick Outflow Driven by Supercritical Accretion May Explain Little Red Dots
The Astrophysical Journal LettersRecent JWST observations have revealed a population of compact, optically red sources known as Little Red Dots (LRDs). A popular interpretation is that LRDs host massive black holes embedded in dense gaseous envelopes, yet the physical origin of such ...
Jun-Rong Liu, Hua Feng, Luis C. Ho
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Transient rotation of photospheric vector magnetic fields associated with a solar flare
Nature Communications, 2018 The violent solar eruptions known as flares are caused by magnetic reconnection. Here, the authors identify a sudden 12°–20° counter clockwise rotation of vector magnetic fields in photosphere, associated with the emissions of moving flare ribbons.
Yan Xu +9 more
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Multi-height probing of horizontal flows in the solar photosphere
Astronomy & AstrophysicsContext. 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. +6 more
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Neutrino Constraints and Detection Prospects from Gamma-Ray Bursts with Different Jet Compositions
The Astrophysical JournalThe 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 +4 more
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Astronomy & AstrophysicsContext. 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. +5 more
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Magnetic Flux Emergence and Solar Eruptions in Partially Ionized Plasmas
The Astrophysical JournalWe 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
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