Results 71 to 80 of about 39,482 (251)

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 ...
openaire   +2 more sources

Solar Wind Heavy Ions and Alpha Particles Within Earth's Magnetosphere and Their Variability With Upstream Conditions

Journal of Geophysical Research: Space Physics, Volume 130, Issue 8, August 2025.
Abstract Working toward the goal of understanding solar wind (SW) entry to the Earth's magnetosphere, this study examines solar‐origin ion composition in the magnetotail. During its trajectory, Wind spent a significant amount of time in the Earth's magnetotail, where its SupraThermal Ion Composition Spectrometer (STICS) measured the mass and mass per ...
S. Colón‐Rodríguez, M. W. Liemohn, J. M. Raines, S. T. Lepri   +3 more
wiley   +1 more source

Recent Evidence for Convection in Sunspot Penumbrae

, 2008
Whereas penumbral models during the last 15 years have been successful in explaining Evershed flows and magnetic field inclination variations in terms of flux tubes, the lack of contact between these models and a convective process needed to explain the ...
Scharmer, G. B.
core   +1 more source

Quasi-thermal Photosphere Emission from Structured Jets of Gamma-Ray Bursts

The Astrophysical Journal
The 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, Jin-Jun Geng, Hao-Xuan Gao, Jing-Zhi Yan, Xue-Feng Wu   +4 more
doaj   +1 more source

Forecasting Coronal Mass Ejections Using Transformers: A Comparative Study of Flare‐Associated Versus Flare‐Independent Approaches

Space Weather, Volume 23, Issue 8, August 2025.
Abstract Forecasting coronal mass ejections (CMEs) remains a challenge, and no reliable, accurate forecasting method has yet been developed. Knowing that CMEs can occur in association with flares, we compare two approaches: (a) forecasting CMEs by coupling to flare forecasting, and (b) forecasting CMEs independently of flare occurrence.
Julio Hernandez Camero, Lucie M. Green
wiley   +1 more source

An active region filament studied simultaneously in the chromosphere and photosphere: I - Magnetic structure

, 2011
A thorough multiwavelength, multiheight study of the vector magnetic field in a compact active region (AR) filament (NOAA10781) is presented. We suggest an evolutionary scenario for this filament.
Antiochos, Anzer, Archontis, Archontis, Aulanier, Aulanier, Aulanier, Babcock, Bard, Bommier, Borrero, C. Kuckein, Canou, Casini, Casini, de La Cruz Rodríguez, del Toro Iniesta, Demoulin, DeVore, Engvold, Fan, Fan, Gibson, Green, Guo, Hindman, Jing, Kippenhahn, Kuckein, Kuperus, Kurokawa, Leka, Leroy, Leroy, Lin, Lin, Lites, Lites, Lites, Low, Low, López Ariste, Mackay, MacTaggart, Magara, Martens, Martin, Martínez-Sykora, Menzel, Merenda, Okamoto, Okamoto, Okamoto, Pevtsov, Pneuman, R. Centeno, Ruiz Cobo, Rutten, Sasso, Scherrer, Socas-Navarro, Sterling, Trujillo Bueno, V. Martínez Pillet, van Ballegooijen, van Ballegooijen, Welsch, Yelles Chaouche, Zirin   +68 more
core   +1 more source

Solar Vortex Tubes. III. Vorticity and Energy Transport

The Astrophysical Journal
This study investigated the mechanisms of vorticity generation and the role of vortex tubes in plasma heating and energy transport. Vortex tubes were identified using the instantaneous vorticity deviation technique in the MURaM data set of a simulated ...
Suzana S. A. Silva, Gary Verth, Istvan Ballai, Erico L. Rempel, Sergiy Shelyag, Luiz A. C. A. Schiavo, Tiago F. P. Gomes, Viktor Fedun   +7 more
doaj   +1 more source

Can a Major Geomagnetic and Auroral Disturbance Originate From a Solar Active Region Close to the Limb?

Space Weather, Volume 23, Issue 8, August 2025.
Abstract When forecasting major geomagnetic storms, it is commonly assumed that coronal eruptions near the solar limb are not of concern. We here discuss two sequences of events: the Fátima storms of January 1938 and the Halloween storms of October/November 2003.
Mike Lockwood, Mat J. Owens, Luke A. Barnard, William Brown, Dechen Gyeltshen   +4 more
wiley   +1 more source

Two-step Emergence of the Magnetic Flux Sheet from the Solar Convection Zone

, 2010
We perform two-dimensional MHD simulations on the solar flux emergence. We set the initial magnetic flux sheet at z=-20,000 km in the convection zone. The flux sheet rises through the convective layer due to the Parker instability, however, decelerates ...
Abbett, Cheung, D'Silva, Fan, Fan, Fan, Hagenaar, Lantz, Magara, Otsuji, S. Toriumi, Sekii, Spruit, T. Yokoyama, Watanabe, Yokoyama   +15 more
core   +1 more source

A model for the formation of the active region corona driven by magnetic flux emergence

, 2014
We present the first model that couples the formation of the corona of a solar active region to a model of the emergence of a sunspot pair. This allows us to study when, where, and why active region loops form, and how they evolve.
Bingert, S., Chen, F., Cheung, M. C. M., Peter, H.   +3 more
core   +1 more source