Results 11 to 20 of about 2,400 (232)

Domain of Influence Analysis: Implications for Data Assimilation in Space Weather Forecasting

Frontiers in Astronomy and Space Sciences, 2020
Solar activity, ranging from the background solar wind to energetic coronal mass ejections (CMEs), is the main driver of the conditions in the interplanetary space and in the terrestrial space environment, known as space weather.
Dimitrios Millas, Dimitrios Millas, Maria Elena Innocenti, Brecht Laperre, Joachim Raeder, Stefaan Poedts, Stefaan Poedts, Giovanni Lapenta   +7 more
doaj   +1 more source

Synchrotron Firehose Instability

The Astrophysical Journal, 2023
We demonstrate using linear theory and particle-in-cell (PIC) simulations that a synchrotron-cooling collisionless plasma acquires pressure anisotropy and, if the plasma beta is sufficiently high, becomes unstable to the firehose instability, in a ...
Vladimir Zhdankin, Matthew W. Kunz, Dmitri A. Uzdensky   +2 more
doaj   +1 more source

High-Frequency Dynamics of Active Region Moss as Observed by IRIS

Frontiers in Astronomy and Space Sciences, 2019
The high temporal, spatial and spectral resolution of Interface Region Imaging Spectrograph (IRIS) has provided new insights into the understanding of different small-scale processes occurring at the chromospheric and transition region (TR) heights.
Nancy Narang, Vaibhav Pant, Dipankar Banerjee, Tom Van Doorsselaere   +3 more
doaj   +1 more source

Exact Calculation of Nonideal Fields Demonstrates Their Dominance of Injection in Relativistic Reconnection

The Astrophysical Journal Letters, 2023
Magnetic reconnection is an important source of energetic particles in systems ranging from astrophysics to the laboratory. The large separation of spatiotemporal scales involved makes it critical to determine the minimum physical model containing the ...
Samuel R. Totorica, Seiji Zenitani, Shuichi Matsukiyo, Mami Machida, Kazuhiro Sekiguchi, Amitava Bhattacharjee   +5 more
doaj   +1 more source

Modelling the total solar eclipse in 2024 with COCONUT

Astronomy & Astrophysics
Context. Coronal modelling is crucial for a better understanding of solar physics and heliophysics. Accurate plasma conditions at the outer boundary of a solar corona lead to more precise space weather predictions.
Baratashvili T., Wang H. P., Sorokina D., Lani A., Poedts S.   +4 more
doaj   +1 more source

Amplitudes and Energy Fluxes of Simulated Decayless Kink Oscillations

Frontiers in Astronomy and Space Sciences, 2019
Recent observations with the Atmospheric Imaging Assembly (AIA) instrument on the SDO spacecraft have revealed the existence of decayless coronal kink oscillations.
Konstantinos Karampelas, Tom Van Doorsselaere, David J. Pascoe, Mingzhe Guo, Mingzhe Guo, Patrick Antolin   +5 more
doaj   +1 more source

Fluorescence in Astrophysical Plasmas [PDF]

, 2013
Following the initial detection by Bowen in 1934 of the strong O III linesbeing due to accidental resonance with strong He II radiation, many strong spectralemission lines are explained as produced by fluorescence. Many of these areFe II lines pumped by H Lyα, as a consequence of strong radiation from hydrogenand a favorable energy level structure for ...
openaire   +3 more sources

Thermal instability in coronal loops: Linking eigenvalue spectra to time-dependent evolution

Astronomy & Astrophysics
Context. Cool, dense condensations such as coronal rain and prominences suggest that coronal plasma can undergo runaway radiative cooling. Connecting this behaviour to linear thermal modes requires a fuller understanding of the deeper connection between ...
Kelly Adrian, Keppens Rony, De Jonghe Jordi   +2 more
doaj   +1 more source

Multithermal Jet Formation Triggered by Flux Emergence

The Astrophysical Journal Letters, 2023
Flux emergence is responsible for various solar eruptions. Combining observation and simulations, we investigate the influence of flux emergence at one footpoint of an arcade on coronal rain as well as induced eruptions.
Xiaohong Li, Rony Keppens, Yuhao Zhou
doaj   +1 more source

Non-thermal electron acceleration in turbulent, post-flare coronal loops

Astronomy & Astrophysics
Context. The generation of energetic, non-thermal electrons during solar flares plays a critical role in energy transportation from the corona to the chromosphere, producing regions of observed intense X-ray emission.
Mora C., Bacchini F., Keppens R.
doaj   +1 more source