Physics
Scientific paper
May 2001
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001agusm..sh31a01j&link_type=abstract
American Geophysical Union, Spring Meeting 2001, abstract #SH31A-01
Physics
7507 Chromosphere, 7546 Transition Region
Scientific paper
We present reduction techniques and first results for detailed fitting of solar spectra obtained with the NASA/National Solar Observatory Spectromagnetograph (NASA/NSO SPM) over a 2 nm bandpass centered on the He I 1083 nm line. The observation for this analysis was a spectra-spectroheliogram obtained at the NSO/Kitt Peak Vacuum Telescope (KPVT) on 00 Apr 17 at 21:46 UT spanning an area of 512 x 900 arc-seconds; the field of view included a coronal hole near disk center as well as surrounding quiet sun. Since the He I line is very weak and blended with nearby solar and telluric lines, accurate determination of the continuum intensity as a function of wavelength is crucial. We have modified the technique of Malanushenko et al. (1992; AA 259, 567) to tie regions of continuua and the wings of spectral lines which show little variation over the image to standard reference spectra such as the NSO Fourier Transform Spectrometer atlas (Wallace et al. 1993; NSO Tech Report #93-001). We performed detailed least-squares fits of spectra from selected areas, accounting for all the known telluric and solar absorbers in the spectral bandpass. The best physically consistent fits to the Helium lines were obtained with Gaussian profiles from two components (one ``cool'', characteristic of the upper chromosphere; one ``hot'', representing the cool transition region at 2-3 x 104 K). In the coronal hole, the transition-region component, shifted by 6-7 km/s to the blue, is mildly dominant, consistent with mass outflow as suggested by Dupree et al., (1996; Ap. J.~467, 121). In quiet-sun spectra there is less evidence of outward flow, and the chromospheric component is more important. All our fitted spectra show a very weak unidentified absorption feature at 1082.880 nm in the red wing of the nearby Si I line.
Jones Philip H.
Malanushenko E. V.
No associations
LandOfFree
Two-Component Fitting of Coronal-Hole and Quiet-Sun He I 1083 nm Spectra does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Two-Component Fitting of Coronal-Hole and Quiet-Sun He I 1083 nm Spectra, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two-Component Fitting of Coronal-Hole and Quiet-Sun He I 1083 nm Spectra will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1274319