Laboratory performances of the solar multichannel resonant scattering spectrometer prototype of the GOLF‐New Generation instrument

Abstract

This article quickly summarizes the performances and results of the GOLF/SoHO resonant spectrometer, thus justifying to go a step further. We then recall the characteristics of the multichannel resonant GOLF-NG spectrometer and present the first successful performances of the laboratory tests on the prototype and also the limitations of this first technological instrument. Scientific questions and an observation strategy are discussed.

Concluding remarks on solar and stellar activities and related planets

“…-The solar core has not yet received so much attention due to the absence of clear dynamical information up to recently. But the GOLF instrument aboard the SoHO satellite appears more and more promising to detect several individual gravity modes, the reason is given in Turck-Chièze et al (2008). The present searches (Turck-Chièze et al, 2004b;García et al, 2007;Mathur et al, 2007Mathur et al, , 2008 favor a rotation in the core between 2 to 5 times the rotation of the rest of the radiative zone.…”

The DynaMICCS perspective

“…10 left). Gravity mode detections by GOLF/SoHO put the first constraints on the rotation of the core, but the solar granulation is the main source of noise in the range below 1 mHz [59]. Since the performance of the SoHO instruments is limited for a sufficient scientific return from these modes, the signal to noise ratio must be improved by a factor 5 to 10 in the range of gravity modes.…”

“…These different points are obtained by putting the cell inside a permanent magnet delivering a magnetic field varying quasi linearly from 2 to 8 kG. A prototype is built which already demonstrates the capability of measuring Doppler velocity at eight heights in the atmosphere of the Sun, see [59]. [59].…”

“…A prototype is built which already demonstrates the capability of measuring Doppler velocity at eight heights in the atmosphere of the Sun, see [59]. [59]. This instrument measures the Doppler shift of the D1 sodium Fraunhfer line by a comparison with an absolute standard given by the sodium vapour cell, the heart of the experiment [59].…”

“…[59]. This instrument measures the Doppler shift of the D1 sodium Fraunhfer line by a comparison with an absolute standard given by the sodium vapour cell, the heart of the experiment [59]. A small portion of the absorption line provided by the resonance of the light in the vapour cell is split into its Zeeman components by means of a static longitudinal magnetic field the strength of which varies along the longitudinal axis in order to explore different heights of the atmosphere, from photosphere to chromosphere taking into account the fact that the patterns of the solar noise are different and consequently are non-coherent.…”