ERIS Science Verification


General Information

The proposal submission was closed on 14 October 2022.

An integral part of the commissioning of a new instrument at the VLT is the Science Verification phase. SV programmes include a set of typical scientific observations that should verify and demonstrate to the community the capabilities of the new instrument in the operational framework of the VLT Observatory. In accordance with its SV Policy and Procedures  ESO encourages the community to submit also highly challenging or risky science observations that will push ERIS to its limits in order to better understand the instrument and mode performance parameter spaces and their envelopes.  

The Enhanced Resolution Imager and Spectrograph (ERIS) is a 1-5 μm instrument for the Cassegrain focus of UT4 at the VLT. It combines an imager (NIX) and an integral-field spectrograph (SPIFFIER).  

ERIS is now offered to the community for Science Verification (SV) for 4 nights in December 2022. All astronomers are invited to participate in this opportunity to obtain unique science with ERIS and thus to demonstrate its scientific capabilities. The community is invited to submit proposals for the ERIS science verification using the Phase 1 web interface. The proposal cycle "ERIS SV" should be used for the proposal submission. Only modes offered in P111 will be accepted for SV observations (see the ERIS User Manual for modes offered in P111). Proposals must not request protected ERIS GTO targets. Please follow the dual-anonymous guidelines applicable since P108.

The deadline for proposal submission was 14 October 2022, 12:00 CEST.

Proposals have been reviewed by an internal panel and allocated time on the basis of scientific merit and feasibility, as well as the demonstrated ability of the Principle Investigators to deliver results on a timely basis. The titles of the selected proposals are listed below.

The observations will be conducted in Service Mode by a dedicated team of ESO astronomers. The ERIS SV team will be able to assist the successful PI’s in the preparation and optimisation of the OBs. The ERIS Exposure Time Calculator has been updated, but may still change as the commissioning is still ongoing.

Proposers are reminded that all SV data are made public worldwide immediately after passing the usual quality control checks.

Short description of ERIS

The Enhanced Resolution Imager and Spectrograph (ERIS) is a near-infrared instrument at the Cassegrain focus of UT4. ERIS has two science arms, SPIFFIER and NIX. SPIFFIER (IFS) is a medium-resolution integral field spectrograph covering J to K band. NIX is capable of imaging between J and M band. ERIS is designed to be used in conjunction with UT4's deformable secondary mirror. The atmospheric turbulence can be sensed with either a natural guide star, or a single artificial star generated with the Adaptive Optics Facility (AOF). ERIS replaces many of the functionalities provided by both NaCo and SINFONI within a single instrument.

ERIS consists of three main instrumental modules:

  • The adaptive optics (AO) module, which uses the AOF Deformable Secondary Mirror (DSM), and one AOF laser, providing natural guide star (NGS) and laser guide star (LGS) visible wavefront sensing with real-time computing capabilities. The AO module allows for single-conjugate adaptive optics (SCAO) operations. Both infrared science instruments, the imager (NIX) and integral-field spectrograph (SPIFFIER), are fed by a dichroic beamsplitter which reflects the visible light to the AO module. The AO module is capable of correcting using guide stars between 1st-11th Gaia RP magnitude (NGS) and 7th-17th Gaia RP magnitude (LGS). AO guide stars must have Gaia BP < 19th magnitude. Observations without the AO module are also supported in some observing modes.
  • The NIX imager, which is designed to provide diffraction limited imaging and low-resolution (R~900) L-band long-slit spectroscopy. The imager has two pixel scales, 13 mas/px and 27 mas/px, providing a field of view of ~26”x26” and 55”x55”, respectively. Currently, only the imaging and pupil plane coronagraphy observing modes are offered.
  • The SPIFFIER integral-field spectrograph (IFS), which is a refurbished version of SPIFFI, the 1-2.5 μm integral field unit formerly on-board SINFONI. This module offers diffraction limited integral field spectroscopy over a user-selectable 0.8” to 8.0” arcsecond field of view, with spatial sampling between 25 and 250 mas/spaxel. There are nine grating configurations; three low-resolution gratings (R~5,000) that span each of the JHK bands and one high-resolution grating (R~10,000).

For a complete list of the available observing modes, capabilities and limitations of the instrument consult the ERIS web page and the user manual.

Phase 2 preparation

The PIs (or their Phase 2 delegates) of accepted proposals must prepare and submit the Phase 2 material using P2. We foresee a deadline of

25 November 2022, 12:00 Central European Time (CET)

to ensure that all observing material can be verified and is ready for the observations during the SV run.

The service mode guidelines for preparing the SV observations are the same as those for regular ERIS observations, available at

Approved programmes

A total of 23 proposals have been allocated SV time. The observations will be performed in Service Mode by a dedicated team and the collected data will become available to the whole user community through the ESO Archive. See VLT SV Policy and Procedures for more details.

Proposal ID Title
110.2574 Resolving host galaxy ionized gas of a luminous quasar at z~2.3
110.2575 Precise dark matter profile measurements in a typical star-forming galaxy at z~1.5
110.2576 Investigating the kinematics of star-forming clumps at high-redshift
110.2578 Feedback or mergers? Disentangling quenching mechanisms at cosmic noon with integral field observations
110.2579 Revealing accretion signatures from a low-mass protoplanet candidate
110.2581 Demonstrating the feasibility of unbiased protoplanetary disc imaging with the vAPP coronagraph of ERIS
110.2583 Probing the kinematics and chemistry of a massive forming star that has recently just had an accretion burst
110.2590 Searching for infrared excess around NGC1850 BH1 and other stars in the core of NGC 1850
110.256S Probing Gas Giant Planet Formation around Very Low Mass Star
110.256Y A detailed study of the 244-440 ONC proplyd with ERIS-SPIFFIER
110.256Z Hunting for the intermediate-mass black hole in NGC300
110.257D The host galaxy of the binary black hole candidate OJ287
110.257H A novel confirmation method for young, giant planets: validating the ERIS K-peak filter
110.257M Emission-line mapping the double ring in the Jackpot gravitational lens: steps towards a multi-plane compound lens model
110.257N Rotation signature in the protostellar outflow cavity from HH 46 IRS
110.257P Investigating an extreme exo-system with IFU spectroscopy and referential-differential imaging
110.257S HH 1177: ERIS resolves the first extragalactic protostellar disk and jet
110.257T Illuminating ionised outflows with ERIS/SPIFFIER
110.258F Planet migration caught in action: Constraining the mass of HD 4113 C by infrared direct imaging with ERIS
110.258G An ERIS view of the iconic HH1 jet
110.258M Weighing the most massive stars with VLT/ERIS
110.258S Dissecting the Most Massive Strongly Lensed SFGs (Pilot)
110.275V The curious case of an outlier: NGC1399 and its supermassive black hole

ERIS pipeline information

The latest versions of the ERIS data reduction pipelines are available for installation for the reduction of your science verification data.  It is important to note that these pipelines are still being developed, do not yet have their full complement of features, have not yet been verified to be fully “science ready”, and may still contain bugs. Therefore, in the spirit of science verification, this pipeline distribution is on a shared risk basis. The pipeline versions are delivered without user manuals or any guarantee of scientific veracity.

Both pipelines have been tested on the ERIS commissioning data and produce advanced science level products. For each science exposure, the ERIS/NIX pipeline removes the instrumental signature from the data (dark-correction, flat-fielding, and linearity correction) and when possible corrects the astrometric plate solution using field GAIA stars and a photometric solution based on field 2MASS stars. Multiple exposures of the same field are combined into a final image stack and a source detection catalogue is created.
For each science exposure, the ERIS/SPIFFIER pipeline removes the instrumental signature from the data (dark-correction, and flat-fielding), calibrates a wavelength solution from
associated arc lamps, applies a field distortion mapping, computes a simple sky subtraction, and generates a resampled 3d data cube and a simple source spectral extraction.   
Both pipelines exist within a Reflex workflow having interactive actors to display intermediate processing results and allow the user to modify pipeline parameters.

Pipeline Installation:

For installing the ERIS pipelines, the following software pre-requisites are required:

For the ERIS science verification we can only support a pipeline installation on a Linux platform using the install_esoreflex script, using our “testing” channel.
A detailed description of the installation can be found at and we provide here an abbreviated description:
    •    download the install_esoreflex script from
    •    make the script executable: chmod u+x install_esoreflex
    •    execute the installation using:    ./install_esoreflex -r testing
    •    follow the on-line installation instructions for installing the ERIS pipeline version 0.8

Running the Pipeline:

    •    To start Reflex, issue the command:  <install_dir>/bin/esoreflex -l
         A list with the available esoreflex workflows will appear, showing the workflow names and their full path.
    •    Start the Reflex workflow by typing:
    •    <install_dir>/bin/esoreflex  eris_spiffier.xml                                  (for running the ERIS/SPIFFIER pipeline)
    •    <install_dir>/bin/esoreflex  eris_nix_img_cal_and_stack.xml       (for running the ERIS/NIX pipeline)
    •    To aid in the visual tracking of the reduction cascade, it is advisable to use component highlighting. Click on Tools -> “Animate at Runtime”,  and enter the number of milliseconds representing the animation interval (100ms is recommended).
    •    Change the directory set-up.  Under “Setup Directories” in the workflow canvas there are seven parameters that specify important directories (green dots). 
The ROOT_DATA_DIR, specifies the working directory within which the other directories are organised and the RAW_DATA_DIR should point to the location of your science verification data.
    •    When ready, click the green arrow button at the top of the workflow canvas to start the workflow

Useful links