Unfolding Overlappogram Data: Preparing for the COOL-AID instrument on Hi-C FLARE
Abstract
During a solar flare, energy released in the corona streams to the solar chromosphere, where plasma is heated and then evaporated upward. The magnitude of these velocities and their evolution as a function of time can provide quantitative information on the magnitude of energy released and the method by which it is transported in a solar flare. Measuring these velocities, however, is quite challenging. Typically, they are measured with single slit spectrometers, where light passing through a long but narrow slit is dispersed and emission lines formed across a range of temperatures are observed. The main issue with using single slit spectrometers to make this measurement is that they are rarely pointed at the right place at the right time. Additionally, their fields of view are limited by narrow slit widths, and although rastering can effectively expand the field of view, it does so at the cost of time. This combination means that single slit spectrometers cannot adequately capture the evolution of the flare velocities. On the contrary, slitless spectrometers can make "overlappograms'', which provide both imaging and spectral information over a large field of view. However, spatial information from different spectral lines can overlap in the dispersion direction, making the data difficult to interpret. Furthermore, the spectral resolution of slitless spectrometers are limited and typically worse than single-slit spectrometers, since no line fitting (and hence sub-pixel sampling) is possible.
For the next generation of the High-resolution Coronal Imager (Hi-C) Rocket Experiment, which we are proposing to launch during a solar flare, we are including the COronal OverLapagram - Ancillary Imaging Diagnostics (COOL-AID) instrument. COOL-AID is a slitless spectrometer based on the COronal Spectrographic Imager in the EUV (COSIE) design, but with a narrow passband coating around 12.9 nm (the same passband as the primary Hi-C telescope), a spatial resolution of ~1"x2", and a velocity resolution of ~5 km/s. The goal of the COOL-AID instrument is to determine the velocity associated with the Fe XXI 12.9 nm spectral line during a solar flare. In this talk, we will demonstrate the unfolding method developed by Cheung et al (2019) to determine the velocity information from a simulated COOL-AID data set.- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSH33A..06W
- Keywords:
-
- 7534 Radio emissions;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7549 Ultraviolet emissions;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7554 X-rays;
- gamma rays;
- and neutrinos;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY;
- 7594 Instruments and techniques;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY