BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:How to diagnose departures from the Maxwellian distribution in the
  solar corona - Dr Jaroslav Dudik (DAMTP)
DTSTART:20141028T130000Z
DTEND:20141028T140000Z
UID:TALK55284@talks.cam.ac.uk
CONTACT:Dr. Jaroslav Dudik
DESCRIPTION:In astrophysics\, the emitted radiation is usually the only so
 urce of iformation about the physical conditions in the emitting medium. P
 hysical properties of the emitting plasma are then derived by analysis and
  modeling of the observed spectra. For a long time\, this has been done un
 der the assumption of a local\, equilibrium Maxwellian distribution.\nWe r
 eport on the SDO/AIA and Hinode/EIS EUV observations of a transient corona
 l loop. EIS captures this loop during its brightening phase as observed in
  most of the AIA filters. We use the AIA data to study the evolution of th
 e loop\, as well as to perform the DEM diagnostics as a function of the no
 n-Maxwellian parameter kappa. Fe XI-XIII lines observed by EIS are used to
  perform the diagnostics of electron density and subsequently the diagnost
 ics of kappa. Using ratios involving the Fe XI 257.772A selfblend\, we dia
 gnose an extreme non-Maxwellian situation with kappa < 2. Using the predic
 ted Fe line intensities derived from the DEMs as a function of kappa\, we 
 show that\, with decreasing kappa\, all combinations of ratios of line int
 ensities converge to the observed values\, confirming the diagnosed kappa 
 < 2. These results represent the first positive diagnostics of kappa-distr
 ibutions in the solar corona despite the limitations imposed by calibratio
 n uncertainties.\n
LOCATION:MR14\,  Centre for Mathematical Sciences\, Wilberforce Road\, Cam
 bridge
END:VEVENT
END:VCALENDAR