Abstract:
The outer most layer of the Sun, also called Corona, reaches temperatures as high as a few million
Kelvin much hotter than underlying photosphere and chromosphere. This phenomenon is
popularly known as coronal heating. Due to such high temperatures, corona is a strong source of
Soft X-rays (<10 kev). Therefore, X-ray telescopes can be used for studying corona without
needing an occulter. Such telescopes can be used to probe corona, its composition and the physics
behind coronal heating and other solar events such as solar flares. An essential tool missing from
arsenal of solar astrophysicists is a soft X-ray imaging spectrometer for the non-flaring corona as
the main focus of the solar astrophysicists have been study of solar flares not the background X ray emission. An imaging spectrometer can do both imaging and spectroscopy simultaneously.
Although XRT on Hinode has very good resolution imaging, it can’t image the non-flaring sun.
The X-ray flux of corona varies by a factor of 1000 during 11 year solar cycle which makes it
difficult to design a single instrument which can be used to study corona during flaring as well as
non-flaring conditions. I have presented science motivation for studying non-flaring sun in soft X rays and present a novel instrument design for the same. I have used Ospex9
suite of SolarSoftWare
to fit observed Soft X-ray spectra from several flares to theoretical models. The modelled spectra
is then convolved with instrument effective area to get instrument response to these flares which
allows us to find how the instrument is going to behave during such events. I have also presented
an algorithm to add counts from different non-flaring observations to find non-flaring solar spectra
which can then be used to model instrument response to non-flaring corona.
