AAS 200th meeting, Albuquerque, NM, June 2002
Session 38. Solar Photosphere, Chromosphere and Transition Region
Display, Tuesday, June 4, 2002, 10:00am-6:30pm, SW Exhibit Hall

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[38.12] New Analysis of He I 1083 nm Imaging Spectroscopy

O. V. Malanushenko (National Solar Observatory), H. P. Jones (NASA's Goddard Space Flight Center)

We apply our new analysis method (Jones, H.P., Malanushenko, E.V, American Geophysical Union, Spring Meeting 2001, abstract #SH31A-01), which uses a spectral standard to determine the continuum and least-squares fitting of all relevant spectral features to removed effects of nearby solar and telluric lines, to imaging spectroscopy in the He I 1083 nm line of coronal holes and quiet sun obtained with the NASA/NSO spectromagnetograph. We find that in coronal holes the central line depth is slightly lower compared to cell centers in nearby quiet network, that the full-width-half maxima (FWHM)of coronal hole profiles is significantly (approximately 35%) higher than in quiet cell centers, and that the coronal hole line-of-sight velocities show a blue shift of 3-4 km/s. Preferential asymmetry with excess blue absorption is clearly evident in the processed profiles. We note that the blue shift of line center is not seen using earlier analysis techniques and explore the reasons for this difference. We suggest that FWHM may be a better coronal hole diagnostic than the lower contrast equivalent width which is currently used. Partial support of this research was provided by NASA Supporting Research and Technology grants under the Sun-Earth Connection program.

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Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.