Paranal: Important recent changes regarding instrumentation and facilities

This section describes important changes which took place during Period 108, as well as changes expected to take place during Periods109 and 110.

General

Distributed Peer Review:

Starting from Period 110, ESO is introducing Distributed Peer Review (DPR) for approximately half of the submitted proposals. In this paradigm, first introduced by Merrifield & Saari (2009), all PIs of proposals qualifying for DPR accept to review a number of proposals (N) submitted by their peers during the same cycle. Correspondingly, they accept that their proposals are reviewed by N peers who submitted proposals in the same cycle. More details and background information on DPR at ESO can be found in Patat et al. (2019), and users should familiarise themselves with the DPR rules and guidelines.
In Period 110, N = 10, and the criteria describing the proposals which qualify for DPR are as follows:

  1. All proposals requesting a total time (including overheads) less than 16 hours are assigned to DPR. This time threshold is set to have an approximate 50/50 distribution between DPR and panels, and it is based on the time request statistics compiled in recent cycles.
  2. Exceptions to this general rule are proposals including at least one ToO run, and DDT proposals.
  3. All other proposals submitted during a regular cycle will be reviewed in the classical way by the OPC and the panels.

In Period 110, the review channel (DPR vs. panels) is assigned at the time of proposal submission, based on the above rules. The PI (or delegated PI; dPI) is informed about the assigned review process and prompted to formally accept the conditions at the time of submission. At this stage the PI/dPI can delegate the reviewer’s role to one of the co-Is listed in the proposal. The delegation can also occur when the list of co-Is is specified.

By submitting a proposal qualifying for DPR, the PI/dPI commits to follow the DPR rules (see DPR rules and guidelines).

New scientific keywords:

Starting in Period 110, a new set of scientific keywords replaces the OPC categories. While preparing their proposals in p1, users must select at least two keywords, and at most five keywords (ten keywords for Large Programmes), except that proposals for Calibration Programmes do not require any keywords. The keywords must be selected in decreasing order of relevance (i.e., the first selected keyword is the most relevant).

Proposal anonymisation:

Period 108 marked the full deployment of the Dual-Anonymous Peer Review (DAPR) for proposals submitted to this Call. Applicants must formulate the scientific rationales of their proposals following the anonymisation rules and examples described in this link, which also gives a detailed description of the DAPR paradigm. While Period 106 was used as a dry run, both to make the community aware of the upcoming implementation of DAPR and to test its practical, procedural and policy aspects, from Period 108 proposal anonymisation is mandatory. Failure to abide by the DAPR rules may be penalised.

The fields Background and Expertise and Data Product Delivery Plan (in the case of Large Programmes) are the only fields of the proposal in which information on the proposing team can be disclosed. These fields will not be included in the material distributed to the referees during the proposal review phase and will only be accessible to them after the ranking phase is completed.

Large Programs:

Large Programmes, those that require 100 hours or more, are accepted for Period 110. Large Programmes can only be submitted in even Periods, i.e., Periods with the proposal submission deadline in March/April. A number of instrument restrictions for Large or Monitoring Programs apply. We refer the reader to Sect. 4.4 in the Call for Proposals Period 110.

Rapid Response Mode (RRM) activation policy:

The RRM policy changed starting in Period 105: on-going observations on any VLT instrument can be interrupted by an RRM triggered on that specific UT, even if the trigger requires a change of focus, unless the relevant programme is specifically protected against an RRM trigger (in case of strictly time-critical programmes). The change has been implemented at UT2 and UT3 and is currently being tested at UT1 and UT4. It is expected that the new RRM will be fully operational by Period 109. More information on the Rapid Response Mode can be found on the Phase 2 page.

UT instruments and facilities

UT1 - Antu

  • KMOS:
    • KMOS, is fully operational since October 2021.

UT2 - Kueyen

  • VISIR:
    • The instrument has been mounted on UT2 in August 2021.

UT3 - Melipal

  • SPHERE: 
    • For the star center observations (obs. Type=C), the WAFFLE pattern amplitude in all modes is calculated automatically and should be left as “AUTO” by default.
  • XSHOOTER:
    • Starting in P108, the convention for acquisition with blind offsets from a reference star has been changed to follow the standard used by VLT instruments. Please be aware of this when preparing your observations.

UT4 - Yepun

  • MUSE:
    • The extension of the GALACSI NFM tip-tilt limiting J-band magnitude has been commissioned. Details are available on the news page of MUSE.
    • Since Period 106, the AO supported MUSE Narrow Field Mode (NFM-AO) is offered for Monitoring and Large Programmes.
    • Target of Opportunity proposals are accepted for MUSE in all its modes.

Incoherent combined focus

  • ESPRESSO:
    • Proposals requesting 4-UT mode must in particular justify its use compared to the 1-UT mode.
    • Monitoring, Large Proposals, and DDT are accepted for 1-UT mode only.
    • There will be a major instrument intervention that will take place during early May 2022. Therefore ESPRESSO will be out of operations between the mid of April and May 2022.

Visitor focus

  • The UT1 Nasmyth A focus is available for Visitor Instruments, but the installation of the field corrector lens for MOONS may impose limitations.
  • Potential users of a visitor focus are requested to consult the VLT Visitor Instruments page.

VLTI instruments and facilities

General:

  • For new users to VLTI needing assistance to prepare their VLTI proposals, the community supported VLTI Expertise Centres - disseminated throughout Europe - can offer in-depth support. They also offer support for advanced data reduction and interpretation.
  • VLTI+UT operations will not be available for several weeks at the beginning of P110 due to the recoating of the UTs Coudé train.
  • Monitoring and Large Programme proposals on the VLTI-UTs and VLTI-ATs are accepted for both GRAVITY and PIONIER without restrictions, and for MATISSE for all modes except the HIGH+ spectral setting and the GRA4MAT mode.

VLTI-ATs:

  • In Period 110, ESO will continue a scheme to optimise operations for aperture synthesis with the VLTI. This scheme only applies to service mode proposals using ATs with PIONIER, GRAVITY and MATISSE. The reader is referred to the Period 110 VLTI manual for further details.

Instruments

  • Two VLTI visitor foci are available in Period 110. Potential users are requested to consult the VLTI Visitor Instrument page.
  • GRAVITY is offered on all AT configurations as well as on all four UTs with the visible (MACAO) and infrared (CIAO, off-axis only) adaptive optics system in Service and Visitor modes.
    • The on-axis mode of the IR wavefront sensor CIAO cannot be offered for the time being due to critical problems that were identified during its commissioning.
    • ESO invites proposals with the goal of performing astrometric measurements, a capability of GRAVITY which is still under development (see, e.g., GRAVITY Collaboration 2017 A&A 602, A94). Proposers who wish to use the astrometric capability and contribute to its development are invited to consult the GRAVITY webpage and contact the astrometric team at least two weeks before the proposal deadline.
  • GRAVITY is offered in a new observing mode dual-field wide is offered for the UTs and the small and astrometric configurations of the ATs starting in Period 110. This mode allows fringe tracking from a target that is up to 30 arcsec away from the science target by using the VLTI Star Separators to separate the beams. The magnitude limits of the fringe tracker and acquisition camera and the expected sensitivity for the science camera in this mode can be found on the GRAVITY webpage and are based on a preliminary characterisation of the mode. Due to the need of good atmospheric conditions (turbulence class 30% and better), observations are strongly encouraged to be carried out in service mode to ensure that the conditions are met. Note that dual-field wide mode only provides relative measures (differential visibilities and phases), no absolute visibilities, due to atmospheric effects when separation increases. Calibrations of the interferometric transfer function are thus not needed and not offered for this mode.
  • MATISSE is offered in Period 110 on the UTs (supported by the visible MACAO AO system) and on the short, medium and large AT configurations in Service and Visitor modes.
    • MATISSE is available with the GRA4MAT mode with ATs fully, and only without chopping for UTs.
    • The instrument offers the choice of various spectral resolving powers covering either L and/or M-band (depending on the resolving power) and N-band. The HIGH+ mode is only available with the GRA4MAT mode.
    • Monitoring and Large programmes are offered in all settings in Period 109, except for the new HIGH+ spectral setting. Additionally, Large or Monitoring Programmes requesting the GRA4MAT mode will not be accepted.
  • PIONIER is offered on all ATs configuration and UTs + MACAO in both service and visitor mode. The limiting magnitudes of PIONIER have been updated following the improvements thanks to the installation of NAOMI. The execution times have been adapted accordingly. See the overview or overheads pages.

Survey telescopes and instruments

VISTA: VIRCAM

  • Due to the imminent installation of 4MOST on VISTA, VIRCAM is no longer offered, and any available time in Period 110 will be used to complete ongoing programmes, if necessary. Nevertheless, the instrument is expected to be available for DDT proposals during part of Period 110.