HR: 10:45h
AN: SH12A-02    [Abstracts]
TI: Response functions of chromospheric lines to changes in temperature and magnetic field
AU: * Uitenbroek, H
EM: huitenbroek@nso.edu
AF: National Solar Observatory Sacramento Peak, P.O. Box 62, Sunspot, NM 88349
AB: Typical densities in the chromosphere are four orders of magnitude smaller than in the underlying photosphere. For this reason the chromosphere is mostly transparent in the optical, aside from wavelengths in the centres of a handful of strong lines. Few viable diagnostics are, therefore, available for routine chromospheric temperature, velocity and magnetic field measurements. Interpretation of these diagnostics is problematic because the low density environment favours radiative line excitation over collisional excitation. As a result, chromospheric lines generally require non-LTE radiative transfer solutions to determine the population of their upper and lower levels, and their formation heights. I will present Non-LTE response functions of several chromospheric lines to investigate the sensitivity of the intensity profile of these lines to changes in temperature and magnetic field. Although these response functions are model dependent they give a first indication of the heights at which we can expect to measure magnetic field strength and geometry in the chromosphere. We will also discuss the sensitivity of the response functions to different solar models
DE: 7500 SOLAR PHYSICS, ASTROPHYSICS, AND ASTRONOMY
DE: 7507 Chromosphere
DE: 7524 Magnetic fields
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly