Search for: All records

Abstract We compare a method for inferring the photospheric vector magnetic field using only spectroscopy to a conventional method based on polarimetry. The magnetic field strengthBand inclination angle can be inferred from the Zeeman splitting using only StokesI. We applied this method to a sunspot observed with the Vacuum Tower Telescope and compared the results to vector magnetograms from the Helioseismic and Magnetic Imager on the Solar Dynamics Observatory, which used a polarimetric inversion. The spectroscopic inversion tends to show higher values inBcompared to the polarimetric data. In quiet regions the discrepancy inBwas typically a factor of two. In the strong sunspot fields, the differences averaged ≈22%. These discrepancies are significant, but comparable to those typically found among magnetograms from different instruments. Our results support the use of the spectroscopic inversion technique to provide a fast and reasonable estimate ofB. 

This white paper is on the HMCS Firefly mission concept study. Firefly focuses on the global structure and dynamics of the Sun's interior, the generation of solar magnetic fields, the deciphering of the solar cycle, the conditions leading to the explosive activity, and the structure and dynamics of the corona as it drives the heliosphere.