Fermilab Dark Energy Program

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Fermilab Dark Energy Program Josh Frieman Introduction and Motivation • Dark Energy Survey • Sloan Digital Sky Survey Results • Future Projects

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Fermilab Dark Energy Program. Josh Frieman. Introduction and Motivation Dark Energy Survey Sloan Digital Sky Survey Results Future Projects. Dark Energy. 1990’s: growing circumstantial evidence (ΛCDM) FNAL theory 1998: SN discovery of cosmic acceleration - PowerPoint PPT Presentation

Transcript of Fermilab Dark Energy Program

Page 1: Fermilab  Dark Energy Program

Fermilab Dark Energy Program

Josh Frieman

• Introduction and Motivation• Dark Energy Survey• Sloan Digital Sky Survey Results• Future Projects

Page 2: Fermilab  Dark Energy Program

Josh Frieman - Fermilab PAC, June 21, 20112

Dark Energy

• 1990’s: growing circumstantial evidence (ΛCDM) FNAL theory• 1998: SN discovery of cosmic acceleration• 1998-2010: confirmation via CMB, LSS, SN surveys SDSS SDSS-II

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Josh Frieman - Fermilab PAC, June 21, 20113

Goals for 2010 Decade• What is the physical cause of cosmic acceleration?

– Dark Energy or modification of General Relativity?• If Dark Energy, is it Λ (the vacuum) or something else?

–What is the DE equation of state parameter w?

• Addressing these questions likely to have profound impact on our understanding of fundamental physics

• Given high priority by P5, DETF, PASAG, Astro2010• Will require multiple, complementary approaches• Our program is well aligned with these goals

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The Dark Energy Survey• Stage III DE project using 4

complementary* techniques: I. Cluster Counts II. Weak Lensing III. Large-scale Structure IV. Supernovae

• Two multiband surveys: 5000 deg2 grizY to 24th mag 30 deg2 repeat (SNe)

• Build new 3 deg2 FOV camera and Data management system Survey 2012-2017 (525 nights)

Blanco 4-meter at CTIO

*in systematics & in cosmological parameter degeneracies*geometric+structure growth: test Dark Energy vs. Gravity

www.darkenergysurvey.org

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I. Clusters

Volume Growth

Number of clusters above mass threshold

Dark Energy equation of state

dN(z)dzdΩ

= dVdz dΩ

n z( )

• Elements of the Method:• Formation and abundance of dark matter halos n(M,z) robustly predicted by N-body simulations • Clusters are proxies for massive halos and can be identified optically to redshifts z>1• Galaxy colors provide photometric redshift estimates for each cluster• Variety of observable proxies for cluster mass: optical richness, SZ flux decrement, X-ray luminosity, weak lensing mass• Cluster spatial correlations cross- check mass estimates Mohr

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Observer

Dark matter halosBackground

sources

• Spatially coherent shear pattern, ~1% distortion• Radial distances depend on geometry of Universe• Foreground mass distribution depends on growth of structure

II. Weak Lensing: Cosmic Shear

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• Cosmic shear angular power spectrum in 4 redshift slices

• Shapes of ~300 million

well-resolved galaxies with z = 0.7

• Improved telescope, new optical corrector, active alignment system should deliver improved image quality for galaxy shape measurements

Weak Lensing Tomography in DES

DES statistical errors shown

Huterer et al

Factor ~30 greater area than CFHTLS

distant

nearby

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Josh Frieman - Fermilab PAC, June 21, 20118

III. Large-scale Structure

CMB angular power spectrumSDSS galaxy correlation function

Bennett, et al

Eisenstein et alBaryon acoustic oscillations (BAO)

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BAO Tomography in DES

Fosalba & Gaztanaga

Galaxy angular power spectrumin redshift bins (relative to model without BAO)

Probe to much higher redshift than SDSS galaxies

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B. D

ilday

SDSS-II: ~500 spectroscopically confirmed SNe Ia, >1000 with host redshifts from SDSS-III. Led by FNAL

IV. Supernovae

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B. D

ilday

SDSS-II: ~500 spectroscopically confirmed SNe Ia, >1000 with host redshifts from SDSS-III. Led by FNAL

IV. Supernovae

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Supernova Hubble DiagramD

ista

nce

mod

ulus

(log

of d

ista

nce)

Kessler et al 2009

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Supernova Hubble DiagramD

ista

nce

mod

ulus

(log

of d

ista

nce)

Kessler et al 2009

DES Simulation:~4000 well-measured SN Ia light curves

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DES Science SummaryFour Probes of Dark Energy• Galaxy Clusters

• ~100,000 clusters to z>1• Synergy with SPT• Sensitive to growth of structure and geometry

• Weak Lensing• Shape measurements of 300 million galaxies • Sensitive to growth of structure and geometry

• Baryon Acoustic Oscillations• 300 million galaxies to z = 1 and beyond• Sensitive to geometry

• Supernovae• 30 sq deg time-domain survey• ~4000 well-sampled SNe Ia to z ~1• Sensitive to geometry

Current Constraints on DE Equation of State

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Josh Frieman - Fermilab PAC, June 21, 201115

DES Science SummaryFour Probes of Dark Energy• Galaxy Clusters

• ~100,000 clusters to z>1• Synergy with SPT• Sensitive to growth of structure and geometry

• Weak Lensing• Shape measurements of 300 million galaxies • Sensitive to growth of structure and geometry

• Baryon Acoustic Oscillations• 300 million galaxies to z = 1 and beyond• Sensitive to geometry

• Supernovae• 30 sq deg time-domain survey• ~4000 well-sampled SNe Ia to z ~1• Sensitive to geometry

Forecast Constraints on DE Equation of State

Factor 3-5 improvement over Stage II DETF Figure of Merit

Planck prior assumed

DES

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Josh Frieman - Fermilab PAC, June 21, 201116

DES Science SummaryFour Probes of Dark Energy• Galaxy Clusters

• ~100,000 clusters to z>1• Synergy with SPT• Sensitive to growth of structure and geometry

• Weak Lensing• Shape measurements of 300 million galaxies • Sensitive to growth of structure and geometry

• Baryon Acoustic Oscillations• 300 million galaxies to z = 1 and beyond• Sensitive to geometry

• Supernovae• 30 sq deg time-domain survey• ~4000 well-sampled SNe Ia to z ~1• Sensitive to geometry

Forecast Constraints on DE Equation of State

Factor 3-5 improvement over Stage II DETF Figure of Merit

Planck prior assumed

DES

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The DES Collaboration

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FermilabUniversity of Illinois at Urbana-Champaign/NCSAUniversity of ChicagoLawrence Berkeley National LabNOAO/CTIODES Spain ConsortiumDES United Kingdom ConsortiumUniversity of MichiganOhio State UniversityUniversity of PennsylvaniaDES Brazil ConsortiumArgonne National LaboratorySLAC-Stanford-Santa Cruz ConsortiumUniversitats-Sternwarte MunchenTexas A&M Universityplus Associate members at: Brookhaven National Lab, U. North Dakota, Paris, Taiwan

Over 120 members plus students & postdocs

Funding: DOE, NSF, UK: STFC, SRIF; Spain Ministry of Science, Brazil: FINEP, FAPERJ, Min. of Science; Germany: Excellence Cluster; collaborating institutions

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Project Structure & Timeline

• Project initiated 2003• DECam R&D 2004-9• Camera construction 2008-11; currently ~93% complete• Final construction, testing, integration now on-going• Ship components to Chile: Sept. 2010-Sept. 2011• Installation: Jan.-Dec. 2011 (main install: Nov-Dec.)• First light on telescope: Jan. 2012• Commissioning: Jan.-April 2012 • Survey: Sept. 2012-Feb. 2017 in 5x105-night seasons

• 3 Construction Projects:• DECam (hosted by FNAL; DOE supported)• Data Management System (NCSA; NSF support)• CTIO Facilities Improvement Project (NSF/NOAO)

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DES ManagementStructure

Fermilab scientists in bold

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Josh Frieman - Fermilab PAC, June 21, 201120

Fermilab Leadership Roles in DES• DES Project Management • Survey Strategy• Calibration• Data Coordination & Validation • DECam Project Management• DECam Construction, Testing, Integration• Mechanical & Electrical Design & Engineering• Image simulations• Installation & Commissioning by DECam team• DECam operations support• Computing: Secondary archive• Science Working Groups (co-lead 4 of 11, active in others)

Currently ~11.5 FTE scientists on DES. Many played key roles in SDSS & SDSS-II and are also wrapping up SDSS analyses (supernovae, clusters, weak & strong lensing, Milky Way dark matter halo structure)

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DES Institutions & Scientists are playing critical roles

• LBNL: CCD development & processing, SN strategy, LSS simulations• Ohio State: SISPI (instrument software: control, DAQ), WL simulations• U. Illinois: Data Management, SISPI• U. Michigan: Filter changer, optical design, LSS simulations, preCAM telescope• SLAC/Stanford: RASICAM cloud camera, calibration, alignment, LSS simulations• Argonne: preCAM, calibration, F/8 handling system, SN simulations• Penn: Weak Lensing pipeline & testing• Brookhaven: Weak Lensing pipeline & testing• Chicago: SN simulations, photo-z, LSS & WL simulations, multi-CCD test vessel• United Kingdom: Optical corrector, Science Committee chair• Spain: Front-end electronics, data quality testing• Munich: Data Management science lead, data quality• CTIO: Telescope improvements, installation, commissioning, operations• Texas A&M: DECam, throughput calibration system, preCAM telescope work• Brazil: Quick Reduce software, Science Portal

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DES Instrument: DECam

Hexapod: optical alignment

Optical Corrector Lenses

CCDReadout

Filters & Shutter

Mechanical Interface of DECam Project to the Blanco

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DECam CCDs• 62 2kx4k fully depleted CCDs: 520 Megapixels,

250 micron thick, 15 micron (0.27”) pixel size• 12 2kx2k guide and focus chips• Excellent red sensitivity• Developed by LBNL• Processed at DALSA, LBNL• Packaged and tested at FNAL DECam / Mosaic II QE comparison

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QE, LBNL (%)QE, SITe (%)

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DECam CCDs• 62 2kx4k fully depleted CCDs: 520 Megapixels,

250 micron thick, 15 micron (0.27”) pixel size• 12 2kx2k guide and focus chips• Excellent red sensitivity• Developed by LBNL• Processed at DALSA, LBNL• Packaged and tested at FNAL DECam / Mosaic II QE comparison

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QE, LBNL (%)QE, SITe (%)

g r i z Y

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CCD Packaging and Testing at Fermilab

• Led by Fermilab Scientists Diehl and Estrada• Fermilab engineer designed the CCD package with production line assembly in mind (from FNAL and LHC silicon vertex detectors) • Operations in 2 clean rooms at Si Det• Built on FNAL technical resources & expertise

(ME, EE, SVD construction at Si Det)• Production Packaging Nov. 2008-Oct. 2010

• 270 2kx4k CCDs packaged and tested • 124 are Science Grade, ready for the focal

plane• 62 + 10 spares are required

• Also have 26 science grade 2kx2k devices; need 12 plus spares.• Mean # bad pixels = 0.12%• Camera extensively tested with engineering-

grade CCDs MCCDTV

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Optics

C4

Filters &Shutter

• Field of view: 2.2o diameter (3 sq deg)• Lenses being aligned in cells and barrel at

University College London prior to shipping to Chile

– Fermilab contributed to optical design in partnership with Universities

S. Kent (FNAL)

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Josh Frieman - Fermilab PAC, June 21, 201127

Telescope Simulator at Fermilab

• Enabled early acceptance testing of DECam components, testing of operations and installation procedures prior to shipping to CTIO, and interleaving of testing, shipping, installation of different components

• Summer 2010-Spring 2011

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DECam Image Simulations:test Data Management System

H. Lin (FNAL) with Science Working Groups

Note bright star artifacts, cosmic rays, cross talk, glowing edges, flatfield (“grind marks”, tape bumps), bad columns, 2 amplifiers/CCD

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DES Observing StrategySurvey Area

Overlap with SDSS equatorial Stripe 82 for calibration (200 sq deg)

• 80-100 sec exposures • 2 filters per pointing (typically)

• gr in dark time• izy in bright time

• Multiple overlapping tilings to optimize photometric calibration

• 2 survey tilings/filter/year• Optimize Dark Energy science

within the allotted 525 nights, based on simulations

• Observing Plan: DES Project Scientist J. Annis (FNAL)

5000 sq deg

2 tilings 3 tilings

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DECam Progress• F/8 2ndary mirror handling system installed at CTIO in Jan. 2011• New cloud camera installed earlier this month (June).• Installation of DECam cooling system starts July.• Science-grade CCDs being installed in DECam now (26 so far), then

will ship imager to Chile for Sept arrival.• Integration & Installation Workshop and Review held in Chile in April.• DES Directors’ Review held at FNAL May 10-11.• UCL aligning optics in cells and barrels, will arrive CTIO mid-Sept.• Asahi (Japan) has produced 2 filters (i and z), are currently completing

a third (y), and have recovered from aftermath of the tsunami. If there are rolling blackouts during peak summer air-conditioning use, it could stretch out delivery of last 1 or 2 filters to the Fall.

• Currently on schedule for installation on the telescope to start Nov. 8.

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DECam Progress• F/8 2ndary mirror handling system installed at CTIO in Jan. 2011• New cloud camera shipped to Chile, will be installed June.• Installation of DECam cooling system starts July.• Science-grade CCDs being installed in DECam now, then will ship

imager to Chile for Sept arrival.• Integration & Installation Workshop and Review held in Chile in April.• DES Directors’ Review held at FNAL May 10-11.• UCL aligning optics in cells and barrels, will arrive CTIO mid-Sept.• Asahi (Japan) has produced 2 filters (i and z), are currently completing

a third (y), and have recovered from aftermath of the tsunami. If there are rolling blackouts during peak summer air-conditioning use, it could stretch out delivery of last 1 or 2 filters to early Fall.

• Currently on schedule for installation on the telescope to start Nov. 1.

DES i and z filters at Asahi

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Josh Frieman - Fermilab PAC, June 21, 201132

DES Operations • Although CTIO will be in charge of installation and

commissioning (FY12) and will operate the instrument (FY12-17), substantial participation by FNAL scientists, engineers, technicians and by the collaboration will be critical to the success of these activities.

• Once DECam components are checked out in the Blanco

dome and ready to install, they move from DOE DECam project funding to DOE DES operations support. FY11: both DECam project and operations support. FY12 and beyond: (mostly) DES operations. NSF supports CTIO observatory ops. Proposal submitted May 2 to NSF for Data Management operations at NCSA.

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DES and mentoring at Fermilab• Since the project began, DES scientists at Fermilab have

mentored:– 23 high school students, both summer and academic-year internships

(including quarknet)– 3 high school teachers– 10 undergrad students, from local colleges to UC Berkeley to S. America

• Andres Plazas: undergrad from Colombia, now grad student at Penn– 5 graduate students, at both masters and PhD level

• Marcelle Soares-Santos: earned PhD from U. Sao Paulo working with FNAL scientists on clusters, now starting FNAL postdoc

– Tom Carter, on sabbatical from College of Du Page• CCD lab at ICFA instrumentation school in 2010: trained 80 students

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Josh Frieman - Fermilab PAC, June 21, 201134

DES and mentoring at Fermilab• Since the project began, DES scientists at Fermilab have

mentored:– 23 high school students, both summer and academic-year internships

(including quarknet)– 3 high school teachers– 10 undergrad students, from local colleges to UC Berkeley to S. America

• Andres Plazas: undergrad from Colombia, now grad student at Penn– 5 graduate students, at both masters and PhD level

• Marcelle Soares-Santos: earned PhD from U. Sao Paulo working with FNAL scientists on clusters, now starting FNAL postdoc

– Tom Carter, on sabbatical from College of Du Page• CCD lab at ICFA instrumentation school in 2010: trained 80 students

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Dark Energy Beyond DES

• LSST• DESpec• BigBOSS• 21-cm

exciting science opportunities to further improve Dark Energy constraints

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Large Synoptic Survey Telescope • Dedicated 8.4m telescope on

Cerro Pachon (next to Tololo)• Gigapixel camera with 10 sq

deg FOV• Top-ranked ground project in

Astro 2010• SLAC is DOE managing

institution for the camera• NSF project (telescope, site,

data management) will be managed by LSST Corp.

• Recent Director’s Review at SLAC

• NSF PDR later this summer

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Large Synoptic Survey Telescope • Fermilab has joined LSST• Fermilab in excellent position to help LSST succeed:

• SDSS/DES survey heritage• Data acquisition system• Data management software • Science analysis• Si Det infrastructure and expertise: industrial-scale silicon-based instrumentation for accelerator and non- accelerator experiments• Modest effort until DECam

ramps down• Will work with SLAC and

LSST Corp to define roles

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Josh Frieman - Fermilab PAC, June 21, 201138

Dark Energy Spectrograph: DESpec• Upgrade of DES currently under study:

– multi-object prime focus spectrograph for the Blanco 4m, interchangeable with DECam

– Redshifts for ~7 million DES galaxies, ~20 million from DES+LSST

– Use DECam infrastructure (cage, barrel, hexapod, most optics, spare CCDs,…): substantial cost saving

– 10 low-cost spectrographs, 4000 robotically positioned fibers• Increased z precision would enhance Dark Energy science

reach of DES by factor ~several, especially testing DE vs. modified gravity: Stage IV DETF

• Enhance DE science reach of Stage IV LSST• Preliminary design and science studies underway

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Massive Spectroscopy of DES TargetsWould enable:

• Clusters: cluster spec. z’s and dynamical masses from velocity dispersions: improve mass-observable cal. for DE

• WL: DESpec Redshift Space Distortions plus DES WL: powerful probe of DE and test of GR+DE vs modified gravity

• LSS: radial BAO (H(z)); growth fn. via Redshift Space Distortions

• SNe, galaxy evolution: host-galaxy z’s and spectroscopic typing (metallicities, stellar masses) to control systematics

• All: calibrate photo-z’s directly and via angular cross-correlation

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• Improved constraints from DES WL+DESpec Redshift Space Distortions

• Constraints even stronger if imaging and spectroscopy cover same sky, as DES+DESpec

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Josh Frieman - Fermilab PAC, June 21, 201141Bernstein & Cai

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Josh Frieman - Fermilab PAC, June 21, 201142

DESpec Concept• 4000 fiber system for the Blanco 4-m at

CTIO,interchangeable with DECam, feeding ~10 low-cost spectrographs (VIRUS)

• FOV: 3.8 sq. deg. (delivered by DECam optics)

• Nominal wavelength coverage: 600 to 1000 nm; could be extended with 2-arm spectrographs

• Resolution: R~3300 with single-arm spectrographs

• Use DECam optics except C5 (dewar window) and add 2 lenses plus ADC

• Use existing tested, spare DECam CCDs as detectors

• Technical challenge: positioners for high fiber density

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DESpec Concept Optical Design

C1C2C3

NewADC

C4

NewC6 C5

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Fiber positioner example

• Here, a FP with 2400 “Cobras”, a “twirling post” with a rotating fiber. Two axes of rotation

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M. Seiffert (JPL) presentation at P.U. 11/09 FiberPatrol Radius

WFMOS “Cobra”

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Fiber Pos. Example

• Echidna: an Australian marsupial with flexible spines

• Also an operating fiber-positioner from AAT with ~400 fibers.

• Spines pivot from mounts near the bases

• Naturally handles a varying target density because the tips are small

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FMOS Echidna on the Subaru

Also was a wfmos proto

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Interchangeable w/ DECam

• To install DESPec 1st stow DECam off-telescope– We are providing hardware to

install/remove DECam as part of that project (see right)

• Then pick up DESpec, and using similar hardware, install it on the end of the barrel.

• In reverse, either store DESpec on the telescope or produce a convenient way to connect/disconnect the fibers.

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• We bring this into the design ab initio so that the process can be done quickly and easily.

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Josh Frieman - Fermilab PAC, June 21, 201147

Rationales for Blanco Spectroscopy

• Uniform, deep imaging catalogs from DES+VHS for targeting enables powerful new science beyond what redshifts alone provide (e.g., WL+RSD)

• Maximally enhance science reach of DES: improve all the DE methods+enable new methods (RSD, radial BAO)

• Hemispheric synergy with LSST: part of a broader eventual strategy for LSST follow-up: extend to ~15,000 sq deg

• Excellent site: seeing, high number of useable nights yield fast (hence cheap) survey

• Low cost & schedule risks by reusing/capitalizing on many DECam components: optics, CCDs,…

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Caveats

• NOAO does not currently have plans for an Announcement of Opportunity for a new instrument on the Blanco following DECam.

• Future of NOAO facilities will depend in part on outcome of NSF AST Portfolio Review in 2012.

• Need to further evaluate the global context of planned & proposed spectroscopic survey facilities: we are positioning DESpec to complement rather than compete with other projects where possible.

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Path Forward• DESpec a natural “upgrade” to the science capability of

DES. Project could structurally follow the path blazed by DES: an international collaboration with DOE+NSF support in the US, building on the successful DES collaboration, with opportunities for new partners.

• First draft of White Paper laying out the science case & reference technical design motivated by science requirements now exists, undergoing refinement.

• Next ~6 months: optimize target selection and technical design for multiple DE probes, confirm with more detailed simulations. Continue to build science case and collaboration. A lab-level review early Fall would be helpful.

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BigBOSS• LBNL-led concept for multi-object spectrograph for the

NOAO Kitt Peak 4-meter telescope to carry out a massive BAO survey

• Follow up targets from PanSTARRS-I and WISE (sky overlap with DES small but potentially useful)

• NOAO agreed to award telescope time in exchange for delivery of the instrument (similar to DES). Construction not yet funded. Includes FNAL scientists Annis, Kent, and Diehl.

• Fermilab could contribute:– mechanical modeling of the telescope (solid model, stray light

analysis, …): Blanco and Mayall essentially identical– Optical corrector: design, management of fabrication, alignment– CCD packaging and testing– Test the instrument using the Telescope Simulator

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DESpec and BigBOSS• Both projects involve 4000-5000-fiber spectrographs on

identical 4m telescopes, with related science goals.• DE reach increases with survey area, so ideally would

survey both north (BB) and south (DESpec).• Similar survey power (area/depth per unit time) for the two

concepts: BB larger FOV, DESpec higher fiber density.• DESpec could cover entire survey areas of DES and LSST,

maximizing synergistic science (weak lensing+redshift distortions).

• DESpec would reuse much of the DECam infrastructure, resulting in cost savings.

• NSF AST will carry out Portfolio Review 2011-12, which will consider the future of the NOAO 4m telescopes.

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Conclusion• DES poised to take the next step in understanding the

nature of dark energy, ramping up operations this year.

• Combination of Fermilab technical and scientific expertise and infrastructure with strengths of partner institutions enables this kind of project.

• DES entering critical phase, and timely operations support will be essential for success.

• Fermilab can make significant contributions to future DE projects, exploiting its infrastructure and technical expertise, building on its experience with SDSS and DES.

• Given limited resources, choices will have to be made, based on compelling science, the ability to make unique, critical contributions, and alignment with national priorities.