Simultaneous spatial spectra of extended solar structures, at a high spatial resolution and temporal cadence are important to track and understand the physics of dynamical evolutionary phenomena. Replacing the slit of a conventional spectrograph with a micro-lens array will then help to capture simultaneous spatial spectra using a large format CCD camera. Such a technique will be useful to study small structures (a few arcsec across) such as Ellerman bombs, kernels of flares, filamentary evolution, and spicules.
At the Richard B. Dunn Solar Telescope, Y. Suematsu (National Astronomy Observatory, Japan) and collaborators L.A. Smaldone (University of Naples), K.S. Balasubramaniam (AFRL/NSO), K. Yoshimura (Kyoto University), S. Hegwer (NSO), H. Ohtani (Kyoto University) have used a micro-lens array (0.6 mm pitch, 50 × 50 lenslets) to observe structures with a spatial sampling of 0.24" in the H spectral line. The spectral sampling is 0.93 Å pixel over a 10 Å bandwidth. The field-of-view is however limited to about 12".
The accompanying figure shows the sample 2-D spectra in H.
There are plans to explore the possibility of extending the observations to other spectral lines such as FeI 6302.5 Å for variation in the line-of-sight of subarcsecond magnetic fields, HeI 10830 Å measurements, and CaII K 3933 Å for measuring dynamic variation of the multiple reversals and high spatial resolution CaII bright point spectroscopy.
Y. Suematsu, L. A. Smaldone,
K. S. Balasubramaniam, K. Yoshimura,
S. Hegwer, H. Ohtani