THE E-ELT DESIGN REFERENCE MISSION

EXECUTIVE SUMMARY

The E-ELT Design Reference Mission (DRM) encompassed a detailed, hands-on exploration of a selected sample of science cases through the analysis of simulated E-ELT data. The purpose of this exercise was (i) to provide a quantitative assessment of the extent to which the E-ELT will be capable of addressing key scientific questions, (ii) to assist the project in making critical trade-off decisions by quantifying their consequences in terms of scientific gains and losses, and (iii) to support the development of the E-ELT Science Case. The overarching aim of the DRM was to help ensure that the E-ELT will be aligned with the scientific aspirations of its community as much as possible.

In summary, the DRM simulations have provided quantitative evidence of the transformational nature of the science programme envisioned for the E-ELT: the E-ELT will undoubtedly revolutionise several fields of astrophysics. However, the simulations have also demonstrated that a fair fraction of this programme lies at the edge of feasibility, leading to the conclusion that much of the science encapsulated by the DRM will indeed require a 40m-class telescope. In addition, the simulations have verified that the site chosen for the E-ELT conforms to the science plans, and that almost none of the capabilities required by these science cases are missing from current adaptive optics and instrumentation plans.

Please see the final DRM Report for full details.

Brief overview

The science cases studied by the DRM were selected by the E-ELT SWG for being prominent examples highlighting the key capabilities of the telescope. Although they cover a wide range of science topics they were not intended to be an exhaustive list of the science that the E-ELT will do. The choice of programs also does not necessarily reflect the expected instrument suite.

The DRM process began with members of the SWG (with help from the community) drafting a 'DRM proposal' for each of the DRM science cases. These proposals were written somewhat in the manner of a regular ESO observing proposal: they briefly summarised the science case and then described a more or less well-defined set of E-ELT observations designed to address the scientific question at hand. The key task of the DRM was to answer, for each science case, the following two questions:

1. What precisely can be achieved with the observations described in the proposal in a given amount of observing time, or, vice versa, how much observing time is needed to achieve a given set of science goals?
2. How do these results depend on the properties of the telescope, the instrument, the AO performance and/or the site? Which features of the E-ELT system are critical to the success of the proposal? What is the limiting factor?

3. Identification of key requirements for each case and quantification of the scientific losses in case the requirements cannot be met, thus helping the project to understand the scientific consequences of any trade-off decisions.

The nature of the chosen DRM cases and/or of the questions was such that they could not usually be answered by a straightforward signal-to-noise consideration. Instead, they required an appropriately realistic simulation of the data 'requested' in the proposals and subsequent analysis. This then constituted the main body of work carried out within the framework of the DRM: the provision of a suite of simulated E-ELT data, their quantitative scientific analysis, and the exploration of scientific and technical parameter spaces in order to identify the critical aspects of each science case. This work was carried out by various members of EScO in collaboration with the SWG.

The simulations required both scientific and technical input. The scientific input was provided by, or agreed upon with, the responsible SWG member. On the technical side, a large number of inputs regarding the characteristics of the telescope, the site, the AO performance, etc., were required. In order to create as much homogeneity across the whole DRM as possible these data were compiled during the first stages of the DRM and collected in a central technical data repository. The simulations used these common data whenever possible.

DRM Workshops

The DRM process and simulation results were discussed with interested members of the community, various instrument study teams and members of the Science Working Group at two DRM workshops in 2008 and 2009.

DRM Report

The final DRM Report provides a comprehensive description of the entire DRM. In particular it includes an account of the DRM process, detailed descriptions of the work carried out for each of the DRM cases, a summary of the results for each case, and the overall conclusions. The original DRM proposals are also included.

The DRM Report is accompanied by a document describing the technical data used for the simulations. The contents of this document are largely identical to the contents of the online technical data repository.