Response to "Stray-light correction in 2D spectroscopy" by R. Schlichenmaier and M. Franz

Abstract

We discuss a recent paper by Schlichenmaier & Franz (SF; 2013, A&A, 555, A84), in which the claim is made that the penumbral dark downflows detected for the first time with the Swedish 1-m Solar Telescope (SST) by Scharmer et al. and Joshi et al. could be produced by overcompensation for straylight. We show that the analysis of SF is fundamentally flawed, because it ignores the constraints on the strength of such straylight from 3D convection simulations and on the spatial extent of the straylight point spread function from the measured minimum intensity in the sunspot umbra. Furthermore, we show that the claim made by SF, that the spatial straylight of Hinode is less than 10%, is false. We conclude that the analysis of SF is of no relevance in relation to the straylight compensation method applied to the SST data.

Published in A&A. Rewording of a few sentences, one sentence removed

References in corpus (8)

• Penumbral structure and outflows in simulated sunspots
• The intensity contrast of solar granulation: comparing Hinode SP results with MHD simulations
• MHD simulations of penumbra fine structure
• How realistic are solar model atmospheres?
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Cited by in corpus (2)

• Lateral downflows in sunspot penumbral filaments and their temporal evolution
• Opposite polarity magnetic field and convective downflows in a simulated sunspot penumbra