HETG Plate Focus Simulation, June 1998
- Capella HETG-First-light Observation
One of the key first-light activities with HETG is a "plate focus" set
of exposures to verify/determine the HETGS focus properties and optimal
focus location. Capella provides strong, narrow lines at high dispersion
for both the HEG and MEG.
- MEG and HEG Capella Spectra
The widths of the bright lines of
O VIII, Fe XVII, Ne X, and Mg XII are measured for each exposure.
- Plot of FWHM vs Defocus
The exposures can be used to construct a FWHM^2 verus defocus
distance plot for the zero-order, MEG line, HEG line. Note that
the HEG and MEG shells are predicted to have slightly different
defocus curves due to the as-built HRMA properties.
- More details are available at
This page is http://space.mit.edu/HETG/swg698oac.html