Description of the working groups

Leaders: Marina Battaglia, Lucia Kleint

Combined studies with RHESSI and IRIS provide unprecedented spectral and spatial diagnostics of flare energy deposition and chromospheric response. RHESSI images and spectra indicate the timing, location, and amount of deposited energy. IRIS spectral line diagnostics provide crucial information on the chromospheric plasma, such as densities and plasma flows as a function of time and space. IRIS also allows to probe the Balmer continuum to investigate flare energetics. This working-group focuses on the discussion of recent results from combined RHESSI and IRIS studies. Questions such as where and how flare energy is deposited (electron beams, thermal conduction), what triggers chromospheric evaporation and how it evolves over the course of the flare, as well as heating and cooling of the chromosphere and transition region will be addressed. We also encourage contributions from studies addressing these questions with other instruments (e.g. Hinode, ground-based observations).

Leaders: Albert Shih, Ron Murphy 

Ions from solar eruptive events are observed directly in space as solar energetic particle events and indirectly through the secondary nuclear gamma-ray lines, pion-decay emission, and neutrons produce in the associated flare. This group will discuss these observations in the context of acceleration processes related to flares and CME shocks and theories of gamma-ray and neutron production. Contemporary gamma-ray data from RHESSI, Fermi, and INTEGRAL, as well as archival data from earlier missions, will be discussed, along with SEP observations. New observations by Fermi/LAT have revealed hours-long high-energy (>~100 MeV) emission in over 25 events whose origin is yet to be explained. Nuclear spectroscopy and imaging add crucial information to understand the origin of these events. We will also discuss recent observations of neutrons in the inner heliosphere and at 1 AU, energetic neutral atoms, and terahertz emission that relate to ion acceleration. We will discuss the relationship between 3He-rich SEP events and the associated flares. We anticipate that these discussions will lead to new scientific objectives that will require new instrumentation and missions.

Leaders: Ryan Milligan, Amir Caspi

The energy released during solar flares often manifests itself in the form of increased SXR and EUV emission due to either direct heating in the corona, or the transport of energy to the chromosphere and subsequent expansion and evaporation. This emission contains a wealth of diagnostic information that can shed light on the physical properties of the heated plasma, such as temperature, density, velocity and energetics, thereby helping us understand the energy release and transport mechanisms. Coincident observations between RHESSI and other longer wavelength instruments have significantly advanced our understanding of flare heating over the years. We hereby solicit talks that focus on joint flare observations between RHESSI and SDO (EVE+AIA), Hinode (EIS+XRT), STEREO/EUVI, GOES (XRS+EUVS), and other SXR and EUV instruments, as well as those that will discuss modelling these emissions.

Leaders: Stephen White, Pascal Saint-Hilaire

Radio imaging capabilities are improving as new facilities, including MUSER, EOVSA, JVLA and MWA, reach full potential. This working group will focus on joint studies using radio observations of energetic electrons in the corona, weighted towards strong magnetic field regions, to complement both imaging and spectral hard X-ray data, and will discuss how these new facilities can best be used for such studies.

Leaders: Säm Krucker, Richard Schwartz

This working group will discuss the next steps in RHESSI imaging including topics such as harmonics, imaging at highest spatial resolution, pile up correction for imaging, high-time resolution imaging, difference imaging with visibilities, etc. It is planned to have short presentations of the current state of each topic, followed by discussions how to best tackle the remaining open issues. The goal is to have a prioritized list of tasks that we want to work on and follow up at the next RHESSI workshop.

Leaders: Eduard Kontar, Gordon Holman

RHESSI X-ray observations in combination with other instruments (EUV, radio, optical, or X-ray) have provided detailed information on spatial, temporal and spectral properties of electron distributions in solar flares. Numerous observations of flares have helped to better identify typical and more unusual properties. These results allow new insights into the flaring process, as well as more quantitative models for both particle acceleration and propagation, and the flaring environment. The working group invites contributions on new theoretical developments and/or modelling endeavours that aim to improve our understanding the processes in flares.