Search Publications
Observing the Sun with the Atacama Large Millimeter/submillimeter Array (ALMA): High-Resolution Interferometric Imaging
de Gregorio-Monsalvo, I.; Kim, S.; De Pontieu, B. +25 more
Observations of the Sun at millimeter and submillimeter wavelengths offer a unique probe into the structure, dynamics, and heating of the chromosphere; the structure of sunspots; the formation and eruption of prominences and filaments; and energetic phenomena such as jets and flares. High-resolution observations of the Sun at millimeter and submil…
Nonequilibrium Processes in the Solar Corona, Transition Region, Flares, and Solar Wind (Invited Review)
Krucker, Säm; Meyer-Vernet, Nicole; Del Zanna, Giulio +12 more
We review the presence and signatures of the non-equilibrium processes, both non-Maxwellian distributions and non-equilibrium ionization, in the solar transition region, corona, solar wind, and flares. Basic properties of the non-Maxwellian distributions are described together with their influence on the heat flux as well as on the rates of indivi…
Comprehensive Analysis of the Geoeffective Solar Event of 21 June 2015: Effects on the Magnetosphere, Plasmasphere, and Ionosphere Systems
Fineschi, Silvano; Stangalini, Marco; Bruno, Roberto +34 more
A full-halo coronal mass ejection (CME) left the Sun on 21 June 2015 from active region (AR) NOAA 12371. It encountered Earth on 22 June 2015 and generated a strong geomagnetic storm whose minimum Dst value was −204 nT. The CME was associated with an M2-class flare observed at 01:42 UT, located near disk center (N12 E16). Using satellite data from…
Observations and Modelling of the Pre-flare Period of the 29 March 2014 X1 Flare
Long, D. M.; Harra, L. K.; Matthews, S. A. +3 more
On 29 March 2014, NOAA Active Region (AR) 12017 produced an X1 flare that was simultaneously observed by an unprecedented number of observatories. We have investigated the pre-flare period of this flare from 14:00 UT until 19:00 UT using joint observations made by the Interface Region Imaging Spectrometer (IRIS) and the Hinode Extreme Ultraviolet …
Automated Spatiotemporal Analysis of Fibrils and Coronal Rain Using the Rolling Hough Transform
Schad, Thomas
A technique is presented that automates the direction characterization of curvilinear features in multidimensional solar imaging datasets. It is an extension of the Rolling Hough Transform (RHT) technique presented by Clark, Peek, and Putman (Astrophys. J.789, 82, 2014), and it excels at rapid quantification of spatial and spatiotemporal feature o…
Diagnostics of Coronal Bright Points using IRIS, AIA, and HMI Observations
Dwivedi, B. N.; Kayshap, P.
We perform the detailed imaging and spectroscopic analysis of two coronal bright points (CBPs). These CBPs are dominated by bright dots or elongated bright features. Their rapid temporal variations lead to a continuous change in their overall morphology at chromospheric and transition-region (TR) temperatures. A 3D potential magnetic field extrapo…
Oscillations in the 45 - 5000 MHz Radio Spectrum of the 18 April 2014 Flare
Monstein, Christian; Rybák, Ján; Karlický, Marian
Using a new type of oscillation map, made from the radio spectra by the wavelet technique, we study the 18 April 2014 M7.3 flare (SOL2014-04-18T13:03:00L245C017). We find a quasi-periodic character of this flare with periods in the range 65 - 115 seconds. At the very beginning of this flare, in connection with the drifting pulsation structure (pla…