Coronal Magnetic Field Measurements
Authors:
- 31 August 2004
- journal article
- research article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 613 (2) , L177-L180
Abstract
A long-standing solar problem has been to measure the coronal magnetic field. We believe it determines the coronal structure and dynamics from the upper chromosphere out into the heliospheric environment. It is only recently that Zeeman splitting observations of infrared coronal emission lines have been successfully used to deduce the coronal magnetic flux density. Here we extend this technique and report first results from a novel coronal magnetometer that uses an off-axis reflecting coronagraph and optical fiber-bundle imaging spectropo- larimeter. We determine the line-of-sight magnetic flux density and transverse field orientation in a two-dimensional map with a sensitivity of about 1 G with 20 spatial resolution after 70 minutes of integration. These full-Stokes spectropolarimetric measurements of the forbidden Fe xiii 1075 nm coronal emission line reveal the line-of-sight coronal magnetic field 100 above an active region to have a flux density of about 4 G.Keywords
This publication has 19 references indexed in Scilit:
- On the Detection of the Signature of Silicon Nanoparticle Dust Grains in Coronal HolesThe Astrophysical Journal, 2003
- A Coupled Model for the Emergence of Active Region Magnetic Flux into the Solar CoronaThe Astrophysical Journal, 2003
- The Hanle Effect of the Two‐Level Atom in the Weak‐Field ApproximationThe Astrophysical Journal, 2002
- Spectral Lines for Polarization Measurements of the Coronal Magnetic Field. II. Consistent Treatment of the Stokes Vector for Magnetic‐Dipole TransitionsThe Astrophysical Journal, 2000
- Coronal magnetic fields from faraday rotation observationsSolar Physics, 1995
- Coronal temperature, density, and magnetic field maps of a solar acitve region using the Owens Valley Solar ArrayThe Astrophysical Journal, 1994
- Coronal emission-line polarization from the statistical equilibrium of magnetic sublevels. I - Fe XIIIThe Astrophysical Journal, 1977
- The Theory of the Polarization of Coronal Forbidden LinesPublications of the Astronomical Society of the Pacific, 1974
- The excitation of the forbidden coronal linesSolar Physics, 1969
- Observations of Five Ionization Stages of Iron in the Solar Corona.The Astrophysical Journal, 1962