We present a compact, self-consistent formulation for the description of polarized radiation from magnetic-dipole transitions occurring in the magnetized solar corona. This work di †ers from earlier treatments by and House in the 1970s, in that the radiative emission coefficients for the Sahal-Bre chot four Stokes parameters, I, Q, U, and V , are treated… (More)
We demonstrate that the atomic alignment of the hyperfine-structure components of the ground level S 1/2 of Na I and of the upper level P 1/2 of the D 1 line are practically negligible for magnetic strengths B > 10 G, and virtually zero for B 100 G. This occurs independently of the magnetic-field inclination on the stellar surface (in particular, also for… (More)
We present the first theoretical, forward calculations of the Stokes profiles of several magnetic dipole (''M1'') coronal emission lines produced in current-carrying magnetic structures. An idealized coronal model of Low, Fong, and Fan is used, which describes a spherically symmetric, hydrostatic background atmosphere, isothermal at a coronal temperature of… (More)
ii Judge et al.
The purpose of this note is to determine the maximum level of polarimetric noise that can be tolerated when performing filter polarimetry of the He I lines at 5876Å and 10830Å. The objective is to ensure that their Stokes parameters still carry enough information for an acceptable magnetic inversion. The simulations reported in this Note cover the cases of… (More)
For about a decade, spectro-polarimetry of He I λ10830 has been applied to the magnetic diagnostics of the solar chromosphere. This resonance line is very versatile, as it is visible both on disk and in off-limb structures, and it has a good sensitivity to both the weak-field Hanle effect and the strong-field Zeeman effect. Recent observations of an… (More)
Comprehensive measurements of magnetic fields in the solar corona have a long history as an important scientific goal. Besides being crucial to understanding coronal structures and the Sun's generation of space weather, direct measurements of their strength and direction are also crucial steps in understanding observed wave motions. In this regard, the… (More)
We derive an analytic expression for the instrument profile of a slit spectrograph, also known as the line spread function. While this problem is not new, our treatment relies on the operatorial approach to the description of diffractive optical systems, which provides a general framework for the analysis of the performance of slit spectrographs under… (More)