Results 11 to 20 of about 14,687 (203)
LOFAR observations of the quiet solar corona [PDF]
Astronomy & Astrophysics, 2018 Context. The quiet solar corona emits meter-wave thermal bremsstrahlung. Coronal radio emission can only propagate above that radius, Rω, where the local plasma frequency equals the observing frequency. The radio interferometer LOw Frequency ARray (LOFAR) observes in its low band (10–90 MHz) solar radio emission originating from the middle and upper ...
Vocks, C. +11 more
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Formation of suprathermal electron distributions in the quiet solar corona [PDF]
Astronomy & Astrophysics, 2008 Summary: Context. Solar wind electron velocity distribution functions (VDFs) show enhanced levels of suprathermal electrons as compared to a Maxwellian distribution. Previous studies show that the suprathermal tails of solar wind VDFs can be fitted by kappa distributions, and that a coronal origin of the suprathermal electrons is possible. Aims.
Vocks, C., Mann, G., Rausche, G.
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Transient small-scale brightenings in the quiet solar corona: A model for campfires observed with Solar Orbiter [PDF]
Astronomy & Astrophysics, 2021 Context. Recent observations by the Extreme Ultraviolet Imager (EUI) on board Solar Orbiter have characterized prevalent small-scale transient brightenings in the corona above the quiet Sun termed campfires. Aims. In this study we search for comparable brightenings in a numerical model and then investigate their relation to the magnetic field and the ...
Chen, Yajie +5 more
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Slow wind belt in the quiet solar corona
Physics of Plasmas, 2023 The slow solar wind belt in the quiet corona, observed with the Metis coronagraph on board Solar Orbiter on May 15, 2020, during the activity minimum of the cycle 24, in a field of view extending from 3.8 R⊙ to 7.0 R⊙, is formed by a slow and dense wind stream running along the coronal current sheet, accelerating in the radial direction and reaching at
E. Antonucci +18 more
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First Radio Evidence for Impulsive Heating Contribution to the Quiet Solar Corona [PDF]
The Astrophysical Journal Letters, 2020 Abstract This Letter explores the relevance of nanoflare-based models for heating the quiet Sun corona. Using meterwave data from the Murchison Widefield Array, we present the first successful detection of impulsive emissions down to flux densities of ∼mSFU, about two orders of magnitude weaker than earlier attempts.
Surajit Mondal, Divya Oberoi, Atul Mohan
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Measuring the Magnetic-Field Strength of the Quiet Solar Corona Using “EIT Waves” [PDF]
Solar Physics, 2013 20 pages, 7 figures, accepted for publication in Solar ...
Long +7 more
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Ion Temperatures in the Quiet Solar Corona
The Astrophysical Journal, 2007 We measure the upper and lower limits of the temperatures Ti for a number of ions observed in the quiescent solar corona from 1996 to 2000, in order to compare with the measured electron temperature Te and test the assumption Ti = Te commonly adopted to measure the plasma nonthermal velocity vnth.
Enrico Landi
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Is There a High‐Energy Particle Population in the Quiet Solar Corona?
The Astrophysical Journal, 2007 A study of spectra emitted by the quiet solar corona indicates that the majority of line intensities originating in low-lying levels are consistent with isothermal plasma of ~1.3 × 106 K. Nevertheless, a number of line intensities and, in particular, those belonging to ions that are typical of higher temperatures are brighter than expected.
Yu. Ralchenko, U. Feldman, G. A. Doschek
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The Equilibrium of Coronal Loops Near Separatrices
The Astrophysical Journal, 2023 We present numerical models from the field-aligned HYDrodynamics and RADiation code (HYDRAD) of a highly asymmetric closed coronal loop with near-singular expansion factor.
Emily I Mason +2 more
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Propagating and Stationary Bright Knots in the Quiet Sun
The Astrophysical Journal Letters, 2022 The question of what heats the solar chromosphere and corona remains one of the most important puzzles in solar physics and astrophysics. Up to now, two mechanisms are considered to work in heating the chromosphere and corona: magnetic reconnection and ...
Jun Zhang +9 more
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