Requirements for the Analysis of Quiet Sun Internetwork Magnetic Elements with EST and ATST

TL;DR

This paper discusses the observational requirements for studying quiet Sun internetwork magnetic elements using EST and ATST, emphasizing the need for high-resolution, high-cadence measurements to capture their dynamics and interactions.

Contribution

It provides specific observational requirements, including field-of-view considerations, based on analysis of magnetic element motions from Hinode data.

Findings

Magnetic elements in supergranular cells move toward the network.

Average travel distance of magnetic elements is about 400 km.

Radial velocity depends on distance from supergranule center.

Abstract

The quiet Sun internetwork is permeated by weak and highly inclined magnetic fields whose physical properties, dynamics, and magnetic interactions are not fully understood. High spatial resolution magnetograms show them as discrete magnetic elements that appear/emerge and disappear/cancel continuously over the quiet Sun surface. The 4-m European Solar Telescope (EST) and the Advanced Technology Solar Telescope (ATST) will obtain two-dimensional, high cadence, high precision polarimetric measurements at the diffraction limit (30 km). Here, we compile the basic requirements for the observation of internetwork fields with EST and ATST (field of view, cadence, instrument configuration, etc). More specifically, we concentrate on the field-of-view requirements. To set them we analyze the proper motion of internetwork magnetic elements across the solar surface. We use 13 hours of magnetograms taken with the Hinode satellite to identify and track thousands of internetwork magnetic element in an isolated supergranular cell. We calculate the velocity components of each element and the mean distance they travel. The results show that, on average, magnetic elements in the interior of supergranular cells move toward the network. The radial velocity is observed to depend on the distance to the center of the supergranule. Internetwork magnetic elements travel 400 on average. These results suggest that ATST and EST should cover, at least, one supergranular cell to obtain a complete picture of the quiet Sun internetwork.