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CHIANTI—An Atomic Database for Emission Lines—Paper. XVIII. Version 11, Advanced Ionization Equilibrium Models: Density and Charge Transfer Effects
Young, P. R.; Del Zanna, G.; Dere, K. P. +4 more
Version 11 of the CHIANTI database and software package is presented. Advanced ionization equilibrium models have been added for low charge states of seven elements (C, N, O, Ne, Mg, Si, and S), and represent a significant improvement especially when modeling the solar transition region. The models include the effects of higher electron density an…
Inferring Fundamental Properties of the Flare Current Sheet Using Flare Ribbons: Oscillations in the Reconnection Flux Rates
Kazachenko, Maria D.; Lynch, Benjamin J.; Corchado Albelo, Marcel F.
Magnetic reconnection is understood to be the main physical process that facilitates the transformation of magnetic energy into heat, motion, and particle acceleration during solar eruptions. Yet, observational constraints on reconnection region properties and dynamics are limited due to a lack of high-cadence and high-spatial-resolution observati…
Magnetic Fields and Plasma Heating in the Sun's Atmosphere
Kleint, L.; de Wijn, A. G.; Tritschler, A. +3 more
We use the first publicly available data from the Daniel K. Inouye Solar Telescope to track magnetic connections from the solar photosphere into the corona. We scrutinize relationships between chromospheric magnetism and bright chromospheric, transition region, and coronal plasmas. In 2022 June, the Visible Spectro-Polarimeter (ViSP) instrument ta…
Solar Flare Ribbon Fronts. II. Evolution of Heating Rates in Individual Flare Footpoints
Polito, Vanessa; Xu, Yan; Kerr, Graham S. +1 more
Solar flare ribbon fronts appear ahead of the bright structures that normally characterize solar flares, and can persist for an extended period of time in spatially localized patches before transitioning to "regular" bright ribbons. They likely represent the initial onset of flare energy deposition into the chromosphere. Chromospheric spectra (e.g…
Transverse MHD Waves as Signatures of Braiding-induced Magnetic Reconnection in Coronal Loops
Antolin, Patrick; Sukarmadji, A. Ramada C.
A major coronal heating theory based on magnetic reconnection relies on the existence of braided magnetic field structures in the corona. In this small-angle reconnection scenario, numerical simulations indicate that the reconnected magnetic field lines are driven sideways by magnetic tension and can overshoot from their new rest position, thereby…
Preliminary Discussion on the Current Sheet
Zhang, Jun; Ding, Tao; Fang, Yuan +1 more
The current sheet is a characteristic structure of magnetic energy dissipation during the magnetic reconnection process. So far, the width and depth of the current sheet are still indefinite. Here we investigate 64 current sheets observed by four telescopes from 1999 to 2022, and all of them have been well identified in the previous literature. In…
From Chromospheric Evaporation to Coronal Rain: An Investigation of the Mass and Energy Cycle of a Flare
Antolin, Patrick; Şahin, Seray
Chromospheric evaporation (CE) and coronal rain (CR) represent two crucial phenomena encompassing the circulation of mass and energy during solar flares. While CE marks the start of the hot inflow into the flaring loop, CR marks the end, indicating the outflow in the form of cool and dense condensations. With the Interface Region Imaging Spectrogr…
On the Response of the Transition Region and the Corona to Rapid Excursions in the Chromosphere
Pereira, T. M. D.; Mathew, S. K.; Louis, R. E. +2 more
Spicules are the thin hair/grass-like structures that are prominently observed at the chromospheric solar limb. It is believed that fibrils and rapid blueshifted and redshifted excursions (RBEs and RREs; collectively referred to as REs) correspond to on-disk counterparts of type I spicules and type II spicules, respectively. Our investigation focu…
Global Impact of Emerging Internetwork Fields on the Low Solar Atmosphere
Gošić, M.; De Pontieu, B.; Sainz Dalda, A.
Small-scale, newly emerging internetwork (IN) magnetic fields are considered a viable source of energy and mass for the solar chromosphere and possibly the corona. Multiple studies show that single events of flux emergence can indeed locally heat the low solar atmosphere through interactions of the upward propagating magnetic loops and the preexis…
Nonthermal Observations of a Flare Loop-top Using IRIS Fe XXI: Implications for Turbulence and Electron Acceleration
Polito, Vanessa; Yu, Sijie; Hayes, Laura A. +2 more
The excess broadening of high-temperature spectral lines, long observed near the tops of flare arcades, is widely considered to result from magnetohydrodynamic turbulence. According to different theories, plasma turbulence is also believed to be a candidate mechanism for particle acceleration during solar flares. However, the degree to which this …