Speaker
Arun Kumar Awasthi
(Institute of Astronomy, University of Wroclaw)
Description
The study of continuum enhancement during a flare is of immense interest owing to the
fact that it represents significant fraction of the impulsive energy release and thus
provides useful diagnostics of the energy deposition and emission processes in the
photospheric and chromospheric heights. We study the spatial and temporal evolution
of continuum enhancement (CE) and co-temporal multi-wavelength emission during two
X1.0 flares of March 29, 2014 and October 25, 2014, respectively. In-depth analysis
of the spectrographic mode observations obtained by IRIS in several wavelengths is
carried out to derive observable parameters of CE viz. intensity contrast, life-time
etc. Morphological evolution of CE is also studied by analyzing the SDO/HMI continuum
filtergrams. Further, we estimate the spatial and temporal evolution of co-temporal
photospheric magnetic field parameters viz. flux, gradient and tilt angle of the
active region during the flares. The spatial and spectral evolution of X-ray sources
during the flares are derived from the RHESSI observations. We present a comparative
overview of the aforesaid parameters for the both the flares. Next, we synthesize
theoretical emission employing 1-D radiative transfer code. A grid of flare
atmospheres are generated based on the pre-existing semi-empirical flare atmospheres
viz. F2 and F3 which are then employed to synthesize the continuum emission in the
wavelength same as that studied from IRIS observations. The parameters derived from
the synthesized profile are then compared with the observed CE parameters as well as
magnetic-field parameters.
Primary author
Arun Kumar Awasthi
(Institute of Astronomy, University of Wroclaw)
