Development of a Diode Laser Heterodyne Spectrometer and Observations of Silicon-Monoxide in Sunspots.
A state-of-the-art, tunable diode laser infrared heterodyne spectrometer has been designed and constructed for ground-based observations throughout the 8-12 micron atmospheric window. The instrument has been optimized for use with presently available tunable diode lasers, and has been designed as a flexible field system for use with large reflecting telescopes. The instrument was aligned and calibrated using laboratory and astronomical sources. Observations of SiO fundamental (v = 1-0) and hot band (v = 2-1) absorption features have been made in sunspots near 8 microns using the spectrometer. These measurements constitute the first reported detection of solar SiO, and the first such measurement using coherent detection. The data permit an unambiguous determination of the temperature-pressure relation in the upper layers of the umbral atmosphere, and support the sunspot model suggested by Stellmacher and Wiehr (Astron. and Astrophys., 7, 432, 1970).
- Pub Date:
- Physics: Astronomy and Astrophysics