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Slipping Magnetic Reconnection, Chromospheric Evaporation, Implosion, and Precursors in the 2014 September 10 X1.6-Class Solar Flare
Polito, Vanessa; Del Zanna, Giulio; Aulanier, Guillaume +7 more
We investigate the occurrence of slipping magnetic reconnection, chromospheric evaporation, and coronal loop dynamics in the 2014 September 10 X-class flare. Slipping reconnection is found to be present throughout the flare from its early phase. Flare loops are seen to slip in opposite directions toward both ends of the ribbons. Velocities of 20-4…
Are IRIS Bombs Connected to Ellerman Bombs?
He, Jiansen; Tian, Hui; Xu, Zhi +1 more
Recent observations by the Interface Region Imaging Spectrograph (IRIS) have revealed pockets of hot gas (∼2-8 × 104 K) potentially resulting from magnetic reconnection in the partially ionized lower solar atmosphere (IRIS bombs; IBs). Using joint observations between IRIS and the Chinese New Vacuum Solar Telescope, we have identified 1…
Simulations of the Mg II k and Ca II 8542 lines from an Alfvén Wave-heated Flare Chromosphere
Kerr, Graham S.; Fletcher, Lyndsay.; Russell, Alexander J. B. +1 more
We use radiation hydrodynamic simulations to examine two models of solar flare chromospheric heating: Alfvén wave dissipation and electron beam collisional losses. Both mechanisms are capable of strong chromospheric heating, and we show that the distinctive atmospheric evolution in the mid-to-upper chromosphere results in Mg II k-line emission tha…
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 …
Continuum Enhancements in the Ultraviolet, the Visible and the Infrared during the X1 Flare on 2014 March 29
Krucker, Säm; Heinzel, Petr; Kleint, Lucia +1 more
Enhanced continuum brightness is observed in many flares (“white light flares”), yet it is still unclear which processes contribute to the emission. To understand the transport of energy needed to account for this emission, we must first identify both the emission processes and the emission source regions. Possibilities include heating in the chro…
Non-LTE Inversions of the Mg II h & k and UV Triplet Lines
Leenaarts, Jorrit; Asensio Ramos, Andrés; de la Cruz Rodríguez, Jaime
The Mg II h & k lines are powerful diagnostics for studying the solar chromosphere. They have become particularly popular with the launch of the Interface Region Imaging Spectrograph (IRIS) satellite, and a number of studies that include these lines have lead to great progress in understanding chromospheric heating, in many cases thanks to the…
Data-driven Radiative Hydrodynamic Modeling of the 2014 March 29 X1.0 Solar Flare
Liu, Wei; Allred, Joel C.; Kleint, Lucia +2 more
Spectroscopic observations of solar flares provide critical diagnostics of the physical conditions in the flaring atmosphere. Some key features in observed spectra have not yet been accounted for in existing flare models. Here we report a data-driven simulation of the well-observed X1.0 flare on 2014 March 29 that can reconcile some well-known spe…
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…
Explosive Chromospheric Evaporation in a Circular-ribbon Flare
Guo, Y.; Li, D.; Ji, H. S. +3 more
In this paper, we report our multiwavelength observations of the C4.2 circular-ribbon flare in active region (AR) 12434 on 2015 October 16. The short-lived flare was associated with positive magnetic polarities and a negative polarity inside, as revealed by the photospheric line-of-sight magnetograms. Such a magnetic pattern is strongly indicative…
Chromospheric Condensation and Quasi-periodic Pulsations in a Circular-ribbon Flare
Li, D.; Zhang, Q. M.; Ning, Z. J.
In this paper, we report our multiwavelength observations of the C3.1 circular-ribbon flare SOL2015-10-16T10:20 in active region (AR) 12434. The flare consisted of a circular flare ribbon (CFR), an inner flare ribbon (IFR) inside it, and a pair of short parallel flare ribbons (PFRs). The PFRs located to the north of the IFR were most striking in t…