Search Publications
Solar Coronal Jets: Observations, Theory, and Modeling
Young, P. R.; Curdt, W.; Raouafi, N. E. +13 more
Coronal jets represent important manifestations of ubiquitous solar transients, which may be the source of significant mass and energy input to the upper solar atmosphere and the solar wind. While the energy involved in a jet-like event is smaller than that of "nominal" solar flares and coronal mass ejections (CMEs), jets share many common propert…
Slow Solar Wind: Observations and Modeling
Li, B.; Harra, L.; Riley, P. +9 more
While it is certain that the fast solar wind originates from coronal holes, where and how the slow solar wind (SSW) is formed remains an outstanding question in solar physics even in the post-SOHO era. The quest for the SSW origin forms a major objective for the planned future missions such as the Solar Orbiter and Solar Probe Plus. Nonetheless, r…
Observing the release of twist by magnetic reconnection in a solar filament eruption
Zhang, Jun; Bi, Yi; Xue, Zhike +9 more
Magnetic reconnection is a fundamental process of topology change and energy release, taking place in plasmas on the Sun, in space, in astrophysical objects and in the laboratory. However, observational evidence has been relatively rare and typically only partial. Here we present evidence of fast reconnection in a solar filament eruption using hig…
Global Sausage Oscillation of Solar Flare Loops Detected by the Interface Region Imaging Spectrograph
Reeves, Katharine K.; Chen, Bin; He, Jiansen +4 more
An observation from the Interface Region Imaging Spectrograph reveals coherent oscillations in the loops of an M1.6 flare on 2015 March 12. Both the intensity and Doppler shift of Fe xxi 1354.08 Å show clear oscillations with a period of ∼25 s. Remarkably similar oscillations were also detected in the soft X-ray flux recorded by the Geostationary …
The Characteristics of Solar X-Class Flares and CMEs: A Paradigm for Stellar Superflares and Eruptions?
Toriumi, Shin; Guedel, Manuel; Harra, Louise K. +10 more
This paper explores the characteristics of 42 solar X-class flares that were observed between February 2011 and November 2014, with data from the Solar Dynamics Observatory (SDO) and other sources. This flare list includes nine X-class flares that had no associated CMEs. In particular our aim was to determine whether a clear signature could be ide…
Hooked Flare Ribbons and Flux-rope-related QSL Footprints
Li, Hui; Aulanier, Guillaume; Schmieder, Brigitte +3 more
We studied the magnetic topology of active region 12158 on 2014 September 10 and compared it with the observations before and early in the flare that begins at 17:21 UT (SOL2014-09-10T17:45:00). Our results show that the sigmoidal structure and flare ribbons of this active region observed by the Solar Dynamics Observatory/Atmospheric Imaging Assem…
Simultaneous IRIS and Hinode/EIS Observations and Modelling of the 2014 October 27 X2.0 Class Flare
Mason, H. E.; Golub, L.; Del Zanna, G. +5 more
We present a study of the X2-class flare which occurred on 2014 October 27 and was observed with the Interface Region Imaging Spectrograph (IRIS) and the EUV Imaging Spectrometer (EIS) on board the Hinode satellite. Thanks to the high cadence and spatial resolution of the IRIS and EIS instruments, we are able to compare simultaneous observations o…
The Relation between Solar Eruption Topologies and Observed Flare Features. II. Dynamical Evolution
Pariat, E.; DeLuca, E. E.; McKillop, S. +4 more
A long-established goal of solar physics is to build understanding of solar eruptions and develop flare and coronal mass ejection (CME) forecasting models. In this paper, we continue our investigation of nonlinear forces free field (NLFFF) models by comparing topological properties of the solutions to the evolution of the flare ribbons. In particu…
Inversion of the radiative transfer equation for polarized light
Ruiz Cobo, Basilio; del Toro Iniesta, Jose Carlos
Since the early 1970s, inversion techniques have become the most useful tool for inferring the magnetic, dynamic, and thermodynamic properties of the solar atmosphere. Inversions have been proposed in the literature with a sequential increase in model complexity: astrophysical inferences depend not only on measurements but also on the physics assu…
Measurements of Non-thermal Line Widths in Solar Active Regions
Warren, Harry P.; Brooks, David H.
Spectral line widths are often observed to be larger than can be accounted for by thermal and instrumental broadening alone. This excess broadening is a key observational constraint for both nanoflare and wave dissipation models of coronal heating. Here we present a survey of non-thermal velocities measured in the high temperature loops (1-4 MK) o…