MS-DESI

Michael Levi

MS-DESI Project Director

March 5, 2013

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Agenda for Today

Welcome BOSS, DES, BigBOSS, DESpec, etal…   

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— Roe (LBL): Welcome— Levi (LBL): MS-DESI intro — White (UCB): Cosmological Physics from Redshift Surveys— Frieman (FNAL): DESpec

• AM session 2: — Kent (FNAL): Optical Design Options and Considerations — Sheinis (AAO): Mohawk Design— Saunders (AAO): Mohawk Performance— Nord (FNAL): SPOKES/Concept and results

• Lunch talk: Kirkby (UCI) – BOSS Science • PM session 1: (1:30)

— Schlegel (LBL): BigBOSS — Sholl (UCB): BigBOSS Technical Concept

• PM session 2: (3:30)— McDonald (LBL): DES/BigBOSS Joint study — Bolton (Utah): BOSS Spectroscopic data — Bailey (LBL): MS-DESI Spectroscopy — Levi: Discussion

• Reception at Roe/Levi’s

BAO Recognized as Top Priorityby Community and DOE

• Rocky-III report “recommends” BAO + RSD• “This science plan used was used to support our program: CD-0

for a mid-scale dark energy spectroscopic instrument (MS-DESI) experiment was signed 9/18/12.” Kathy Turner, Oct. 16, 2012

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“There is compelling case for an advanced wide-fieldspectroscopic survey, which would enable dark-energy information at the Stage IV level through the techniques of Baryon Acoustic Oscillations and Redshift Space Distortions. A spectroscopic survey would produce important dark-energy science results in the period between the completion of the Stage III Dark Energy Survey (DES) photometric project and the arrival of results from the Stage IV LSST photometric project.”

BOSS Delivers BAO Results

MS-DESI will be Stage-IV

Experiment Galaxies Figure of Merit

BOSS 1.5 M 24

MS-DESI 20-30M + Ly-a 240 - 340

Stage III

Stage IV

BOSS is Stage-IIINeed lots of galaxies to achieve Stage-IV result.Stage-IV FOM should be 3 times better, i.e. >75 (BAO only).

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calculations by Pat McDonald

MS-DESI Status

• The DOE Office of Science signed Critical Decision 0 (CD-0) "Mission Need" for a Mid-scale Dark Energy Spectroscopic Instrument (MS-DESI) experiment in September 2012.  

• The CD-0 calls for a new instrument to be operated in the 2018 - 2022 time period and perform Stage IV dark energy measurements.

• The CD-0 means that we have started the conceptual design phase of the project (ie. Phase A).

• Both BigBOSS & DESpec made in-person presentations to DOE in November.

• DOE has charged LBNL to be the managing lab for MS-DESI with the responsibility for designing and fabricating the instrumentation and managing the experimental operations to achieve the dark energy science results.  

• No “downselect” between BigBOSS and DESpec

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MS-DESI Status

• While it is the case that we do not yet have a telescope site for MS-DESI, the DOE Office of High Energy Physics (HEP) is having regular discussions with the National Science Foundation Division of Astronomical Sciences to investigate a suitable telescope facility to host the experiment.    

• To support a 2018 start,  the site decision will be coming in spring, and will drive our schedule for Critical Decision 1  (CD-1), "Approval of Alternative Selection and Cost Range", in late FY13 (equivalent to Phase B).  

• A CD-1 in FY13 will support an operations start for MS-DESI in 2018. The process leading up to a CD-1 approval includes a major DOE review of the Conceptual Design Report.  

• MS-DESI has a future budget profile from DOE and is now an “active project”

• Received an “science alternatives analysis” charge. Report due this month.

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“Critical Decision 0 (CD-0) for a Mid-scale Dark Energy Spectroscopic Instrument (MS-DESI) experiment (MS-DESI) was approved by the Associate Director of the Office of High Energy Physics, James Siegrist, on September 18, 2012. The CD-0 statement calls for the development of new instrumentation to provide a spectroscopic survey, during the gap in data-taking between the current and planned imaging surveys in the DOE program, to perform Stage IV dark energy measurements using Baryon Acoustic Oscillations. In December 2012, HEP assigned responsibility for designing and fabricating the instrumentation and managing the experimental operations to achieve the dark energy science results to LBNL. ….“In your role as the Project Director for MS-DESI, I am requesting that you lead a science alternatives analysis to support HEP discussions with NSF for a suitable telescope and to inform the decision-making in the next few months. Assuming the same instrument design in both locations, you should determine what the impact on the dark energy science return would be in operating the instrumentation on either telescope. 

Alternatives Analysis & Selection

Statement of Principles by DOE & NSF

• “The DOE HEP goal is to carry out these dark energy studies in 3–5 years, which will require from 70–100% of the dark time on the chosen telescope.

• “DOE HEP is willing to pay for all operating costs for the dedicated dark energy observing time, but is also open to NSF contributing to the operating costs if NSF has an interest in the science.

• “Because the Mayall telescope on Kitt Peak is known to be available for usage in the 2017-2018 time frame, and allocation of MS-DESI observing time on that telescope has already been socialized with the broader AST community, NSF could support a time frame of April 2013 for making a decision to use the Mayall. The Blanco telescope on Cerro Tololo is not known to be available, and allocation of MS-DESI observing time on that telescope has not yet been proposed in the broader AST community. Hence a decision to use the Blanco is not likely to be possible in the April 2013 time frame.

• “At the moment there is no funding identified to support use of any remaining nights for MS-DESI instrument on the Mayall telescope on Kitt Peak, although there have been expressions of interest submitted to NOAO. DOE should be prepared to support complete funding of telescope operations if there is no funded use for the remaining nights. 9

Interim Collaboration Steering Committee

• This committee is an advisory body for bootstrapping the science collaboration.  — There will be a separate technical organization for the

construction project. In the technical organization we will try to pair scientists with the technical managers. To be established after site selection

• Current board make-up was to reflect DESpec/BigBOSS:— [principals] DESpec: Kron/Lahav, BigBOSS: Levi/Schlegel; — University: Eisenstein/Honscheid.  Roe is ex-officio.— Want to quickly extinguish BigBOSS/DESpec separation— Will expand board significantly after site selection.

• This committee will be focused initially on:— Building a world-class consortium— Alternatives analysis report

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• Initial report writing started• Have request for public input (some comments

received)• Looking at: 1) science, 2) cost, 3) performance.

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Science Alternatives Analysis

• Studies tell us that ~55% of the available time is “dark” and can be used for MS-DESI for all tracers (all wavelengths) plus another 10% is useable for all but the blue wavelength (1940 hours of 3000 hours total/yr). Historically, another 10% is required for engineering studies.

• Dark Energy measurement be proportionately improved by integral time

Science Alternatives Analysis

calculations by Michael Lampton

Visibility…

Zone 1 (red) 7.9K deg2., visible only from KPNO; Zone 2 (green) 8.8K deg2., visible from both KPNO and CTIO; and Zone 3 (blue) 7.5K deg2., visible only from the CTIO.

For targeting considerations, Zone 2 can be expanded to 10.8K deg2

Graphic & calculations by David Schlegel

Science Alternatives Analysis

• Imaging Surveys for Target Selection— A fiber-fed spectrograph needs a database of where to point.

• The pre-imaging survey for MS-DESI will require a minimum 2-band survey to ~23.5th mag (galaxy). This is a relatively shallow and therefore rapid survey.

• If MS-DESI is in the North, targeting (10,800 deg2 ) is from DECam, plus 7,900 deg2 from the above sources.

• If MS-DESI is in the South, targeting (18,300 deg2 ) is from DECam.• Submitted a letter-of-intent on behalf of MS-DESI to NOAO TAC to

request survey time for equatorial imaging target selection (a 3 year survey).

• Zone 2 & 3: The survey rate is 160 deg2 per night with DECam • Zone 1: 19 deg2/nt with MOSAIC/KPNO, 34 deg2/nt with

WIYN/pODI, 52 deg2/nt with CFHT/Megacam, and 65 deg2/nt with ZTF.

Science Alternatives Analysis

Schedule

• Site selection in April

• Run-up to CD-1:— Subsystem reviews— Independent review (project advisory panel) — Agency review— CD-1 FY13Q4

• CD-2/3a FY14Q3

• On-sky 2018

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$2.1M Award from GBMF

• $2.1M grant from the Gordon and Betty Moore Foundation.• Will fund the construction of:

— Spectrograph #1— One or two glass blanks for the corrector

• Funds in hand

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Conclusions

• MS-DESI is happening

• Send comments regarding alternatives analysis

• Site selection…

• Talks today highlight the great work to date.

• Kathy Turner will tell us “incentivize people to contribute to the execution of the project (hardware, software, etc…)”

• Looking forward to a great scientific endeavor!

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