Near-IR internetwork spectro-polarimetry at different heliocentric angles

TL;DR

This study investigates the magnetic properties of the solar internetwork at different angles on the solar surface using near-infrared spectropolarimetry, finding no significant variation with heliocentric angle and suggesting isotropic magnetic distribution.

Contribution

It provides the first detailed analysis of internetwork magnetic signals at various heliocentric angles, challenging existing models of internetwork magnetism.

Findings

Magnetic signals show no significant variation with heliocentric angle.

Internetwork magnetic elements are likely isotropically distributed.

Results discard network-like models for internetwork magnetism.

Abstract

The analysis of near infrared spectropolarimetric data at the internetwork at different regions on the solar surface could offer constraints to reject current modeling of these quiet areas. We present spectro-polarimetric observations of very quiet regions for different values of the heliocentric angle for the Fe I lines at 1.56 micron, from disc centre to positions close to the limb. The spatial resolution of the data is 0.7-1". We analyze direct observable properties of the Stokes profiles as the amplitude of circular and linear polarization as well as the total degree of polarization. Also the area and amplitude asymmetries are studied. We do not find any significant variation of the properties of the polarimetric signals with the heliocentric angle. This means that the magnetism of the solar internetwork remains the same regardless of the position on the solar disc. This observational fact discards the possibility of modeling the internetwork as a Network-like scenario. The magnetic elements of internetwork areas seem to be isotropically distributed when observed at our spatial resolution.