The Enhanced Resolution Imager and Spectrograph for the VLT

The Enhanced Resolution Imager and Spectrograph (ERIS) is an instrument that both extends and enhances the fundamental diffraction limited imaging and spectroscopy capability for the VLT. It replaces two instruments that were being maintained beyond their operational lifetimes, combines their functionality on a single focus, provides a new wavefront sensing module for natural and laser guide stars that makes use of the Adaptive Optics Facility, and considerably improves on their performance. The observational modes ERIS provides are integral field spectroscopy at 1-2.5 mu m, imaging at 1-5 mu m with several options for high-contrast imaging, and long-slit spectroscopy at 3-4 mu m. The instrument is installed at the Cassegrain focus of UT4 at the VLT and, following its commissioning during 2022, has been made available to the community.

Automated summary

The Enhanced Resolution Imager and Spectrograph (ERIS) is an instrument that replaces two instruments at VLT, extends and enhances their capabilities, utilizes Adaptive Optics Facility for wavefront sensing, and significantly improves performance. It offers integral field spectroscopy, imaging, and long-slit spectroscopy across different wavelength ranges. Installed at the Cassegrain focus of UT4, ERIS has been made available to the community after its commissioning in 2022.