HR: 1330h
AN: SP13A-03    [Abstracts]
TI: The Effects of Magnetically-Induced Spectral Line Profile Changes on Helioseismic and Flare Observations
AU: * Edelman, F
EM: frances.edleman@yale.edu
AF: Yale University, P.O.Box 204950 SM 1724, New Haven, CT 06520 United States
AU: Hill, F
EM: fhill@noao.edu
AF: National Solar Observatory, PO Box 26732, Tucson, AZ 85726-6732 United States
AU: Howe, R
EM:
AF: National Solar Observatory, PO Box 26732, Tucson, AZ 85726-6732 United States
AU: Komm, R
EM:
AF: National Solar Observatory, PO Box 26732, Tucson, AZ 85726-6732 United States
AB: We have modeled the effect of changes in the shape of the spectral line used for the GONG and MDI observations, and we investigate the consequences for measurements of properties of oscillations and flares. We find that magnetic field measurements are not very sensitive to line shape changes, but velocity estimates do strongly depend on line variations. Using simulated observations of a flare we find that recently observed associated magnetic field changes are not due to line shape changes. On the other hand, a simulation of an oscillation indicates that at least part of the observed amplitude suppression in an active region is due to variations in the line shape. We also report preliminary results of the effect of vertical phase variations across the line profile on the helioseismic observations. This work is carried out through the National Solar Observatory Research Experiences for Undergraduate (REU) site program, which is co-funded by the Department of Defense in partnership with the National Science Foundation REU Program. This work utilizes data obtained by the Global Oscillation Network Group (GONG) project, managed by the National Solar Observatory, which is operated by AURA, Inc. under a cooperative agreement with the National Science Foundation. The data were acquired by instruments operated by the Big Bear Solar Observatory, High Altitude Observatory, Learmonth Solar Observatory, Udaipur Solar Observatory, Instituto de Astrofísica de Canarias, and Cerro Tololo Interamerican Observatory.
DE: 7522 Helioseismology
DE: 7524 Magnetic fields
SC: Solar Physics Division - AAS [SP]
MN: 2005 Joint Assembly