Charles Kankelborg September 11, 2001
The Sun is a source of ionizing radiation, energetic particles and solar wind. I am fascinated by the highly structured solar atmosphere that gives rise to these phenomena. My current research revolves around two basic scientific questions:
To address these questions, I am pursuing several lines of research.
The extreme ultraviolet (EUV) line radiation from the Sun has been the subject of many imaging and spectrographic experiments. I am convinced that further progress in observing the solar atmosphere requires a new synergy between imaging and spectroscopy in EUV. Last year, I proposed a narrow slitless spectrograph imaging at multiple orders over a narrow passband. This new instrument type will make it possible for the first time to obtain EUV line profile information over a 2D field of view in a single snapshot. My collaborators and I are now developing a sounding rocket payload, the Multi-Order Solar EUV Spectrograph (MOSES), as a proof of concept. A next logical step would be to develop an instrument of this type to investigate the high speed dynamics of magnetic reconnection in solar flares.
I am also interested in adapting EUV/visible dichroics (developed for high power laser research) to enable simultaneous use of a single telescope aperture in two or more spectral bands. This would increase the capability of space based instruments that are constrained in mass and volume.
In the corona, energy is stored in electric currents that affect the geometry of the field, resulting in current sheets and complex topologies. State-of-the art numerical models of these fields require massive computational resources, spent mainly to overcome numerical diffusion. I am pursuing a new computational approach that treats magnetic field lines (I call them “fluxons”) as the fundamental computational entities in a Lagrangian picture. A first-generation fluxon code now models nonlinear force-free magnetic fields in 2D and 3D on a fast workstation. The long range objective is to model ideal magneto-hydrodynamics in very complicated, realistic geometries. The ideal limit applies to many astrophysical plasmas because of the large length scales involved; this work may therefore find a variety of applications.
The solar atmosphere is observed to be highly complex, structured and dynamic. Our theories aim to address the underlying physics, but are cartoonish when viewed alongside the data. Meaningful comparison between theory and observation therefore requires detailed forward modeling. The magnetic field modeling discussed above is one step in my effort to develop tools for forward modeling. I have also constructed a gasdynamic coronal loop model incorporating modern transition region physics in a configurable geometry. The latter has been combined successfully with the “magnetic separator” reconnection theory of Dana Longcope (MSU) to generate predictions of X-ray bright point light curves. I am now pursuing a collaborative effort with Craig Deforest of Southwest Research Institute to apply the magnetic field model to eruptive prominences.