High-resolution observations of the solar photosphere, chromosphere, and transition region

L H M Rouppe Van Der Voort,T Leifsen,D R Graham,A Popovas,V H Hansteen,V M J Henriques,A Sainz Dalda,G J M Vissers,C Quintero Noda,P Zacharias,S Jafarzadeh,H Skogsrud,R Timmons,A Ortiz,Bart De Pontieu ,Mikołaj Szydlarski ,J De La Cruz Rodrıguez ,Tiago M D Pereira ,Jayant Joshi ,Clara Froment ,Ainar Drews ,Suchismita Bose ,Petra Kohutova ,Georgios Chintzoglou ,G Scharmer ,Mats Carlsson ,Lucia Kleint ,Magnus M Woods ,D J Schmit ,Juan Martínez-Sykora ,Milan Gošić ,D Nóbrega-Siverio ,Eamon Scullion

doi:10.1051/0004-6361/202038732

Abstract

NASA’s Interface Region Imaging Spectrograph (IRIS) provides high-resolution observations of the solar atmosphere through ultraviolet spectroscopy and imaging. Since the launch of IRIS in June 2013, we have conducted systematic observation campaigns in coordination with the Swedish 1 m Solar Telescope (SST) on La Palma. The SST provides complementary high-resolution observations of the photosphere and chromosphere. The SST observations include spectropolarimetric imaging in photospheric Fe I lines and spectrally resolved imaging in the chromospheric Ca II 8542 Å, Hα, and Ca II K lines. We present a database of co-aligned IRIS and SST datasets that is open for analysis to the scientific community. The database covers a variety of targets including active regions, sunspots, plages, the quiet Sun, and coronal holes.

Highlights

The solar atmosphere is a very dynamic region, where fundamental physical processes take place on small spatial scales and short dynamical time scales, often leading to rapid changes in the thermodynamic state of the plasma
The combination of multiple spectral diagnostics, preferably with sensitivity to line formation conditions that cover a large range in temperatures, densities, and magnetic field topologies, are of fundamental importance for advancing our understanding of the solar atmosphere
Ground-based telescopes allow for high resolution in photospheric and chromospheric diagnostics, as well as high-sensitivity polarimetric measurements of the magnetic field with instrumentation that can be more complex than in space, and which is not limited by data transfer rates

Summary

Introduction

The solar atmosphere is a very dynamic region, where fundamental physical processes take place on small spatial scales and short dynamical time scales, often leading to rapid changes in the thermodynamic state of the plasma Resolving these processes in observations requires high resolution in the combined spatial, temporal, and spectral domains. Target selection is organized through a system with relatively short communication lines and allows for effective coordination with ground-based telescopes and other observing facilities This has opened up possibilities to expand on IRIS’s rich arsenal of spectral diagnostics, for example by adding photospheric and chromospheric spectropolarimetry and high-resolution imaging in various spectral lines at and around the area covered by the IRIS spectrograph slit. The release of the corresponding full spatial resolution SST data is planned for future data releases

Observations and data processing

SST observing programs

IRIS and SST co-alignment

Data in the database