Search Publications
An optically thin view of the flaring chromosphere: non-thermal widths in a chromospheric condensation during an X-class solar flare
Kowalski, Adam F.; Kerr, Graham S.; Allred, Joel C. +2 more
The bulk of solar flare energy is deposited in the chromosphere. Flare ribbons and footpoints in the chromosphere therefore offer great diagnostic potential of flare energy release and transport processes. High-quality observations from the Interface Region Imaging Spectrograph (IRIS) spacecraft have transformed our view of the Sun's atmospheric r…
Detection of decayless oscillations in solar transition region loops
Guo, Mingzhe; Gao, Yuhang; Van Doorsselaere, Tom +1 more
Context. Decayless kink oscillations have been frequently observed in coronal loops, serving as a valuable diagnostic tool for the coronal magnetic field. Such oscillations have never before been reported in low-lying loops of the transition region (TR).
Aims: The aim of this study is to detect decayless kink oscillations in TR loops for the …
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…
Small-scale magnetic flux emergence preceding a chain of energetic solar atmospheric events
Rouppe van der Voort, L. H. M.; Joshi, R.; Froment, C. +4 more
Context. Advancements in instrumentation have revealed a multitude of small-scale extreme-ultraviolet (EUV) events in the solar atmosphere and considerable effort is currently undergoing to unravel them.
Aims: Our aim is to employ high-resolution and high-sensitivity magnetograms to gain a detailed understanding of the magnetic origin of such…
Spectroscopic evidence of cool plasma in quiet Sun small-scale brightenings detected by HRIEUV on board Solar Orbiter
Parenti, S.; Bocchialini, K.; Dolliou, A.
Context. A large number of small and short-lived EUV brightenings have been detected in the quiet Sun (QS) over the past three years by the High Resolution Imager of the Extreme Ultraviolet Imager (HRIEUV) on board Solar Orbiter. It remains uncertain whether these events reach coronal temperatures and, thus, whether they directly contribute to cor…
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…
Generic low-atmosphere signatures of swirled-anemone jets
Nóbrega-Siverio, Daniel; Aulanier, Guillaume; Schmieder, Brigitte +4 more
Context. Solar jets are collimated plasma flows moving along magnetic field lines and are accelerated at low altitude following magnetic reconnection. Several of them originate from anemone-shaped low-lying arcades, and the most impulsive ones tend to be relatively wider and display untwisting motions.
Aims: We aim to establish typical behavi…
Chromospheric and coronal heating in an active region plage by dissipation of currents from braiding
De Pontieu, Bart; Hansteen, Viggo; Sainz Dalda, Alberto +3 more
The question of what heats the outer solar atmosphere remains one of the longstanding mysteries in astrophysics. Statistical studies of Sun-like stars reveal a correlation between global chromospheric and coronal emissions, constraining theoretical models of potential heating mechanisms. However, spatially resolved observations of the Sun have sur…
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…
Decomposing the AIA 304 Å Channel into Its Cool and Hot Components
Antolin, Patrick; Auchère, Frédéric; Soubrié, Elie +2 more
The AIA 304 Å channel on board the Solar Dynamics Observatory (SDO) offers a unique view of ≈105 K plasma emitting in the He II 304 Å line. However, when observing off-limb, the emission of the (small) cool structures in the solar atmosphere (such as spicules, coronal rain and prominence material) can be of the same order as the surrounding hot co…