TY - JOUR

T1 - Acoustic shock waves in the solar chromosphere from millimeter observations

AU - Loukitcheva, Maria A.

AU - Solanki, Sami K.

AU - White, Stephen

PY - 2006/3/1

Y1 - 2006/3/1

N2 - We argue that millimeter continuum observations promise to be an important diagnostic of chromospheric dynamics and the appropriate wavelengths to look for dynamic signatures are in the range 0.8-5.0 mm. We have analyzed the millimeter intensity spectrum expected from the dynamic model of the solar non-magnetic atmosphere of Carlsson & Stein (1992, 1995, 1997, 2002, hereafter CS) together with the interferometric observations of the quiet Sun obtained at a wavelength of 3.5 mm with the Berkeley-Illinois-Maryland Array. Model radio emission at millimeter wavelengths is found to be extremely sensitive to dynamic processes in the chromosphere, if these are spatially and temporally resolved. The estimated millimeter brightness temperatures are time-dependent, following changes in the atmospheric parameters, and result in clear signatures of waves with a period of 180 s seen in the radio intensity as a function of time. At the same time, the interferometric observations of the internetwork regions reveal significant oscillations with amplitudes of 50-150 K in the frequency range 1.5-8 mHz. We give an estimate of the influence of the limited available spatial resolution of observations on the comparison with the predictions of dynamic models. We are able to establish a correspondence between the CS model predictions and the observational data if we assume that the horizontal coherence length of the oscillations is on the order of 1 arcsec.

AB - We argue that millimeter continuum observations promise to be an important diagnostic of chromospheric dynamics and the appropriate wavelengths to look for dynamic signatures are in the range 0.8-5.0 mm. We have analyzed the millimeter intensity spectrum expected from the dynamic model of the solar non-magnetic atmosphere of Carlsson & Stein (1992, 1995, 1997, 2002, hereafter CS) together with the interferometric observations of the quiet Sun obtained at a wavelength of 3.5 mm with the Berkeley-Illinois-Maryland Array. Model radio emission at millimeter wavelengths is found to be extremely sensitive to dynamic processes in the chromosphere, if these are spatially and temporally resolved. The estimated millimeter brightness temperatures are time-dependent, following changes in the atmospheric parameters, and result in clear signatures of waves with a period of 180 s seen in the radio intensity as a function of time. At the same time, the interferometric observations of the internetwork regions reveal significant oscillations with amplitudes of 50-150 K in the frequency range 1.5-8 mHz. We give an estimate of the influence of the limited available spatial resolution of observations on the comparison with the predictions of dynamic models. We are able to establish a correspondence between the CS model predictions and the observational data if we assume that the horizontal coherence length of the oscillations is on the order of 1 arcsec.

KW - Shock waves

KW - Sun: Chromosphere

KW - Sun: Oscillations

KW - Sun: Radio radiation

UR - http://www.scopus.com/inward/record.url?scp=33750739192&partnerID=8YFLogxK

U2 - 10.1017/S174392130600158X

DO - 10.1017/S174392130600158X

M3 - Article

AN - SCOPUS:33750739192

VL - 2

SP - 104

EP - 107

JO - Proceedings of the International Astronomical Union

JF - Proceedings of the International Astronomical Union

SN - 1743-9213

IS - 233

ER -