Ground-Based Solar Research An Assessment and Strategy for the Future (1998) / Chapter Skim
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Appendix I: Infrared Solar Physics
Appendix I: Infrared Solar Physics
Pages 105-114
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From page 105... ...
Appendix I Infrared Solar Physics . NOTE: The material in this appendix is reprinted from material made available to the Task Group on Groundbased Solar Research by the scientific staff of the National Solar Observatory.
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From page 106... ...
Scientific Staff National Solar Observatory National Optical Astronomy Observatories July 1997 ~ Summary Infrared observations beyond 2.5 ,um are expected to contribute uniquely to solving two key problems of solar physics: the role of weak surface magnetic fields in the solar cycle and the origin of the chromosphere. More generally, infrared measurements of magnetic field strength as well as temperature, density, and chemical composition are the most direct and sensitive of any known techniques.
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From page 107... ...
Another advantage of the 12-pm lines, connected with their height of formation, concerns the extrapolation of surface magnetic field measurements into the outer atmosphere, an application that has become increasingly important with the advent of high-quality coronal images from Yohkoh and SOHO. The extrapolation techniques usually assume that the field is force-free, but this is a poor assumption for visible magnetograph lines such as Fe ~ 630.2 nm and even poorer for the deep I.56-,um lines.
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From page 108... ...
. We confine ourselves here to the briefest reminder that the infrared spectrum offers proven advantages for measuring the "bread-and-butter" quantities of stellar physics: temperature, density, and chemical composition' as well as magnetic field strength.
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From page 109... ...
1997; Oka 1997) required a new approach to the solution of the vibration-rotation Schrodinger equation to reproduce the solar spectrum; the authors expect that the solar results will spur similar improvements in the chemical analysis of other hot polyatomic molecules.
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From page 110... ...
to relate directly to visible-light measurements. A larger aperture would greatly improve the quality and value of wide spectral range observations; but to preclude future access to the thermal infrared altogether would be akin to completely eliminating infrared or radio wavelengths as tools of nighttime astronomy - which is not even a remote possibility.
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From page 111... ...
6 Near-Term Scientific Objectives at the McMath-Pierce The McMath-Pierce Telescope can make progress toward all the scientific objectives discussed above, as well as others that were not highlighted. Specifically, we will: investigate the thermodynamics of the photo sphere and chromosphere using CO, OH, and He ~ ~ 083-nm spectroscopy in conjunction with visible measurements such Ca K · Imaging; measure the distribution of magnetic field strength down to ~ 00 G outside active regions using simultaneous 12-pm and )
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From page 112... ...
1994, Infrared Solar Physics (IAU Symp.
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From page 113... ...
and the Photospheric Spectrum from 460 to 630 cm' (16 to 22 ~m) (Tucson:NSO)
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