Call for White Papers to define the Gemini InfraRed-Optical Spectrometer (GIROS)

UPDATED FEBRUARY 7

January 2012

Introduction

Gemini Observatory is embarked on a new round of instrumentation development, with an emphasis on creating as competitive as possible an instrument suite within the technical limitations of the telescopes and fiscal constraint of projected budgets. The Gemini High-resolution Optical Spectrograph (GHOS; www.gemini.edu/node/11698) and Gemini Remote Access to CFHT ESPaDOnS Spectrograph (GRACES; www.gemini.edu/sciops/future-instrumentation-amp-current-development) are the first instruments under consideration in this new round. The Gemini Science and Technology Advisory Committee (STAC; http://www.gemini.edu/science/#stac) has recommended that the next capability to be pursued is single-object spectroscopy at medium resolution simultaneously covering optical and near-infrared wavelengths. As such, the Observatory and STAC solicit Gemini community participation to define the specific requirements and goals of this desired capability, provisionally named the Gemini InfraRed-Optical Spectrometer (GIROS).

An important first step in this process is to identify science goals and objectives that provide, in a demonstrative way, a solid justification for this new capability. These science cases are particularly important to defining minimum requirements and desired goals, e.g. minimum/maximum wavelength and minimum/ideal spectral resolution. Since the vast majority of the expertise in this area rests within the community, Gemini Observatory is issuing this call for "White Papers to define the Science Case for a Gemini InfraRed-Optical Spectrometer (GIROS)" in order to help construct the scientific cases that will later be use to form the technical requirements for this capability. Observers, and other parties with an interest in using this type of broad-bandwidth, moderate-resolution spectroscopy at Gemini are invited to participate. Please note, however, that this call is neither a solicitation for instrument technology or design concepts nor for proposals to fund, build, or observe with such an instrument.

Guidelines

While this call is specifically intended to attract creative thinking, please consider the following guidelines:

First, the goal of this call is to establish the scientific rationale for doing simultaneous optical and near-infrared medium-resolution spectroscopy on an 8-m telescope, so we are only interested in position papers that help present a strong scientific justification for this capability. e.g. How does the science require or benefit from the simultaneous broad wavelength coverage? Why do the existing capabilities not fulfill this need? Also, it is important to be forward looking and include future scientific research; any capabilities developed from this call would be available in the latter half of the current decade and should be able to focus on these opportunities.

Second, while the scientific justification for GIROS is the sole issue behind this solicitation, this project faces technical challenges imposed by the fact that the Gemini telescopes have only Cassegrain foci with limited instrument envelopes and masses and budget constraints in the current era of fiscal austerity. Anticipating that tradeoffs between cost and capability may have to be made to fit within budgetary and technical limitations, science cases that illuminate the edges of the potential parameter space and well-justify required minimum parameters are particularly useful. e.g. What are the cutoff wavelengths in the ultraviolet/optical and near-infrared required to achieve the desired science? What is the minimum versus ideal spectral resolution?

Finally, as a means of starting a discussion but not to unduly restrict it, we present "straw-man" requirements, a result of the Gemini STAC November 2011 meeting, for consideration: a 5–8" single-slit spectrograph, simultaneously covering wavelengths from approximately 350 nm, where the silver reflectivity drops off, to 2.5 microns at a resolution high enough to achieve read-noise limited performance between OH emission lines (R~4000-8000). Being a "straw-man" concept, we welcome all critical and constructive comments and emphasize that this is a concept only — if this concept is unsupported scientifically, it will not be pursued.

Directions for submitting a White Paper

If you would like to participate in and receive updates on the process, please contact Maxime Boccas, as soon as possible (mboccas@gemini.edu or +56 51 205 643). Include, if known, what specific topic will be addressed and the names of any co-authors. The deadline for the receipt of papers is March 15, 2012, to be sent by email to Maxime Boccas (mboccas@gemini.edu). White Papers should be no more than five (5) pages long (including all material such as figures and references), written as succinctly as possible, and, most importantly, put into universal context. Moreover, to help consolidate the effort, we encourage the formation of special interest groups to write a single position paper for a given research topic (i.e., this is not a popularity contest and the primary goal is to build a broad and strong scientific case for this capability, so multiple papers expressing the same justification is redundant).

Submitters should clearly identify (preferably at the top of the document) if a paper should be considered confidential. Otherwise, papers may be publicly released at some later time.

Revision history:

• V1.0, 13 January 2012
• V2.0, 2 February 2012

The received science cases will be compiled and reviewed by the STAC, with help from Gemini and possibly other representatives of our user community. This combined and processed list of science cases would later be used to guide GIROS's eventual technical design, if it goes forward. Gemini believes that under 2 CFR 215.43, see http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=42baeec524da9983c25a7ec574919cf1&rgn=div8&view=text&node=2:1.1.2.10.2.3.12.22&idno=2 groups who develop requirements or specifications for an instrument may be barred from later bidding on designing and building that instrument. This restriction is one of the reasons why we are not soliciting instrument and technical concepts at this time.