A Ground Based Multiline Spectrometer for the Analysis of Solar Atmospheric Waves

Abstract

The presence of magnetic fields may influence the propagation characteristics of acoustic waves in the solar atmosphere. Investigating amplitude and phase properties may thus help to reveal the 3D geometry of magnetic fields above sunspots and activity regions. The height resolution of this type of measurements was limited in the past by the limitations of existing spectrometers.We have developed a double-etalon based spectrometer allowing us to observe solar velocities with an unprecedented number of spectral lines. A test version of this instrument has been installed at the Vacuum Tower Telescope of the Kiepenheuer-Institut at Tenerife in July 2009 for the first time. 16 spectral lines were observed at a cadence of 60 secs over a period of 4 hours. The field of view was 100"x100".The multiple diagnostic diagrams resulting from these observations clearly reveal the simultaneous p-mode ridge structure at every height level from the deep photosphere (538.0 nm C I) to the chromosphere (656.3 nm H-alpha). We are confident that individual acoustic modes may be vertically traced through the atmosphere at yet unsurpassed height resolution in the future.