Giant Segmented Mirror Telescope

Science Working Group

September,11 2002

GSMT Science Working Group

September 11, 2002

Meeting Minutes:

Participants:  Rolf Kudritzki, Betsy Gillespie, Paul Ho, Doug Johnstone, Matthew Colless, Terry Herter, Larry Stepp, Jeremy Mould, Sam Barden, Arjun Dey, Joan Najita, Steve Strom, Doug Simons, Mike Bolte, Knut Olsen Jonathan Lunine, Claire Max, Chris McKee, Chic Woodward, Ray Carlberg, and Jill Bechtold.


(1) Rolf introduced three new members:

Chris McKee, Jonathan Lunine and Ray Carlberg

With the nomination of Ray to serve, Doug Johnstone will retire from the committee, with thanks from us all and the agreement to contact him for help re ISM and star formation problems.

Alan Dressler has been contacted and is still considering the offer to serve

(2) Wayne Van Citters has been contacted by Rolf. He will compose a letter to the AAS membership describing the role of the GSMT SWG and has agreed to serve as NSF contact 'pro-tem' until a replacement for Dan Weedman has been identified. We look forward to interacting with Wayne at our next meetings.

(3) Rolf requested that the SWG website be given the appearance of even greater independence from the NOAO/NIO website so that it is clear that the group is a creature of the NSF.

ACTION: Strom to work with Stepp and Novack to develop models for better presenting the website to the world.

(4) The committee agreed to focus its efforts to reviewing the role of GSMT in the science areas identified in the 18 July meeting.

Presentations and Action Items

(1) Science leads presented summaries of the key science enabled by GSMT in the era of NGST and ALMA. Copies of the presentations will be posted on the SWG website.

ACTION: Novack to gather electronic versions of the presentations from Stepp and to post them on the site.

(2) ACTION items follow:

(i) quantify science case and requirements for spectroscopic observations of KBOs (Lunine)

(ii) develop the science case for high mass star-formation science with emphasis on IMFs in rich, dense clusters and direct detection and characterization of disks (Strom working with Olsen, McKee).

Identify simulations needed to evaluate performance of 'real' AO systems. These would include:

(a) adopting realistic MCAO point spread functions, taking into account short-term variability in the IPSF; apply to crowded field photometry in support of the rich cluster IMF problem (Rigaut working with Max and Olsen; support from R. Blum at CTIO

(b) evaluating the feasibility of detecting low surface brightness disks using plausible high performance AO systems (Max and Rigaut).

(iii) model detectability of tidal gaps produced by giant planets embedded in accretion disks (Max and Rigaut working with Lunine; Ho); see ii-b above

(iv) Develop quantitative understanding of the detectability of giant planets as a function of planet mass; age; angular separation as a function of: telescope diameter; assumed performance of     extreme-AO/coronagraph combinations (Max; Lunine; Herter; Najita).

Max reported that much of this supporting work has been done in support of the CELT science case.

Extend the above to spectroscopic characterization of planets (achievable sensitivity; resolution requirements) (Lunine; Herter; Najita)

(v) carry out realistic simulations of crowded field photometry aimed at parsing stellar population components of galaxies; include the effects of PSF variation as a function of position; short-term time variability (Rigaut; Max; Olsen; Bolte).  Understand quantitatively the 'returned science' as a function of MCAO field of view (Olsen).

Develop quantitative understanding of the trades between (much lower) Strehl optical, and higher Strehl near-infrared photometry 

(vi) develop a quantitative understanding of the sample sizes required in order to map the gaseous and galactic components of the early universe by comparison with numerical simulations.

Understand the trades among:  FOV; telescope diameter; multiplex advantage. (Colless; Carlberg; Dey). Also quantify the potential gains from 'enhanced seeing' performance (Colless; Rigaut).

(vii) outline the elements of the science cases for galaxy cluster evolution; galaxy morphology evolution; determining cosmological parameters; constraining evolution of physical constants (Colless; Mould; Carlberg; Bechtold; Gillespie)

(viii) summarize the requirements for AO (all science task leads). Forward these requirements to Strom and Max who will synthesize the summaries and develop a prioritized list of needed simulations.

An AO task group (Rigaut; Max; Strom) will develop and circulate a simulation plan. As a minimum subset, the crowded field and high contrast scence will be attacked.

(ix)  develop the case for Galactic Center science (focus on potential of astrometry to probe the vicinity of the black hole). (Ho, via discussions with Ghez and others as needed).

(x)  develop an 'integration time calculator' to provide a common basis for quantitative estimates. Build on NIO and CELT work. The goal should be rapid circulation of common assumptions regarding detector characteristics; atmospheric properties; etc. and dissemination of 'beta-testing' level tools before the end of 2002.  (Gregory will take the lead; working with Bolte).

(xi) further develop the QSO/AGN cases and quantify comparison with NGST capabilities (Bechtold).

(xii) distribute all materials circulated at the 29 July meeting to new members. (Novack).

(xiii) Can McKee review the science cases, identify links to key problems in high energy physics, and contact team leads with recommendations re making/expanding those links?

(xiv) Bolte will contact Thorsett &Woosley re potential i GRB programs. 

Preparation for (late) October SWG Meeting

(1) Science leads will prepare power point presentations and distribute them to the SWG one week prior to the meeting. The presentations should adhere to the following template:

(i) brief statement of the problem

(ii) key measurements needed to solve the problem

(iii) current status; contribution of 6-10m telescopes to its solution

(iv) quantitative summary of the need for a next generation telescope 

(v)   instrument/detector/AO requirements

(vi) science return as a function of key telescope parameters: diameter; FOV; multiplex advantage; AO performance; wavelength coverage; emissivity......

(vii) synergies with/complementarities to ALMA; GSMT; Planck; SNAP: Constellation-X; Herschel.................... Much more attention needs to be paid to this and presenters will be asked to identify quantitative arguments or the process needed to develop same.

(viii) identification of key issues that require further research; simulations; calculations.

Leads will consult with the working group members outlined in the July 29 minutes (posted on the GSMT SWG website); with newly-added members of the working group; and with outside consultants as needed.

Goals of the October SWG Meeting

(1) Review the adaptive optics roadmap and provide feedback to the CfAO-NIO working group prior to its presentation to the CAA in December, 2002.

(2) Review science cases and identify issues for clarification; simulations; etc. prior to the late January, 2003 meeting of the SWG.

(3) Identify mechanisms for quantifying the relationship between 'returned science' and key telescope/instrument performance parameters -- a key precursor to evaluating the efficacy of design concepts

(4) Define and assign tasks (simulations; science-vs-performance parameters) to be completed before JAN 03 SWG meeting.

To accomplish these tasks will require a two-day meeting. Holly Novack will contact SWG members and NIO support staff to ascertain their availability during the period 23 October to 24 November. She will work with Kudritzki to ensure Wayne's availability.


GSMT: Stellar populations

Seismology of Solar-Type Stars

Galaxy Evolution

Quasar Hosts

Appendix 2.D Star and Planet formation with a GSMT

Towards a GSMT Science Case: Large Scale Structure and Cosmology 


    Holly Novack / / December 6, 2003