The Accelerating UniverseProbing Dark Energy with SupernovaeEric Linder Berkeley Lab

Evidence for AccelerationSupernovae Ia: DE , w=p/ , w=dw/dz Observation -- Magnitude-redshift relationAge of universe: Contours of t0 parallel CMB acoustic peak angle: t0=14.00.5 Gyr [Flat universe, adiabatic perturbations]CMB Acoustic Peaks: Substantial dark energy, e.g. 0.49 < < 0.74 [Small GW contribution, LSS, H0]Large Scale Structure: Power spectrum Pk, Growth rate, looks [simulations]

Supernova Cosmology

A Dark Energy UniverseTyson

Correlation of Age with CMB Peak AngleKnox et al.DASI data only

CMB Power Spectrum and Tegmark

CMB Power Spectrum

Matter Power Spectrum

CMB + 2dF (no SN)Efstathiou et al.

MAP Sky CoverageWrightNov 01Jan 02Apr 02Oct 02Wright

Dark EnergySupernova data shows an acceleration of the expansion, implying that the universe is dominated by a new Dark Energy!Remarkable agreement between Supernovae & recent CMB results.Credit STScI

Dark Energy Theory1970s Why M ~ k?1980s Inflation! Not curvature.1990s Why M ~ ?2000s Quintessence! Not ?Cosmological constant is an ugly duckling Dynamic scalar field is a beautiful swanLensing =0.7+0.1-0.2Chiba & YoshiiSupernovae =0.72+0.08-0.09SCP, HiZLy Forest =0.66+0.09-0.13D. Weinberg et al.

: Ugly DucklingAstrophysicist: Einstein equations gab p = -Naturally, =const= PL= 10120Today MField Theorist: Vacuum Lorentz invariantTab ~ab = diag { -1, 1, 1, 1} p = -Naturally, Evac ~ 1019 GeV E ~ meV=0?

Fine Tuning Puzzle why so small? Coincidence Puzzle why now?

Scalar Field: Beautiful SwanAstrophysicist: Friedmann equations (/a)2=(8/3)(m+) /a=-(4/3)(m++3p)

Field Theorist: Lagrangian L=(1/2)a a-V()(1/2)2-V Tab= ab - L gab=K+Vp=K-Vw=p/ = (K+V) / (K-V) [-1, +1]Slow Roll (Inflation) K

Fundamental Physics (a) = (0) e-3dlna(1+w) ~ a-3(1+w) w(z)=w0+wzAstrophysics Cosmology Field Theoryr(z)Equation of state w(z) V()V ( ( a(t) ) )SNCMBetc.Would be number one on my list of things to figure out- Edward Witten

Right now, not only for cosmology but for elementary particle theory this is the bone in our throat- Steven WeinbergIs =0 ?What is the dark energy?

Type Ia Supernovae Characterized by no Hydrogen, but with Silicon Progenitor C/O White Dwarf accreting from companion Just before Chandrasekhar mass, thermonuclear runawayStandard explosion from nuclear physics

1 Parameter Family Homogeneity

Hubble diagram low z

Hubble diagram - SCP0.20.51In flat universe: M=0.28 [.085 stat][.05 syst]Prob. of fit to =0 universe: 1%redshift z0.20.40.60.81.0

Supernova Cosmology

OriginalCurrent (offset)Near TermProposedSupernovae Probes - Generations

SNAP: The Third Generation

Dark Energy Equation of State

Hubble Diagram

Dark Energy Exploration with SNAPCurrent ground based compared withBinned simulated data and a sample ofDark energy models

Probing Dark Energy Models

From Science Goalsto Project DesignScienceMeasure M and Measure w and w (z)Data Set RequirementsDiscoveries 3.8 mag before maxSpectroscopy with S/N=10 at 15 binsNear-IR spectroscopy to 1.7 m

Statistical RequirementsSufficient (~2000) numbers of SNe Iadistributed in redshiftout to z < 1.7Systematics RequirementsIdentified and proposed systematics:Measurements to eliminate / bound each one to +/0.02 magSatellite / Instrumentation Requirements~2-meter mirrorDerived requirements:1-square degree imager High Earth orbitSpectrograph ~50 Mb/sec bandwidth (0.35 m to 1.7 m)

Mission Design

SNAP Survey Fields

GigaCAMGigaCAM, a one billion pixel arrayApproximately 1 billion pixels ~140 Large format CCD detectors required, ~30 HgCdTe DetectorsLarger than SDSS camera, smaller than H.E.P. Vertex Detector (1 m2)Approx. 5 times size of FAME (MiDEX)

Focal Plane Layout with Fixed Filters

Step and Stare and Rotation

High-Resistivity CCDsNew kind of CCD developed at LBNL Better overall response than more costly thinned devices in useHigh-purity silicon has better radiation tolerance for space applicationsThe CCDs can be abutted on all four sides enabling very large mosaic arraysMeasured Quantum Efficiency at Lick Observatory (R. Stover):

LBNL CCDs at NOAOSee September 2001 newsletter at http://www.noao.eduNear-earth asteroidsSeyfert galaxy black holesLBNL Supernova cosmologyCover picture taken at WIYN 3.5m with LBNL 2048 x 2048 CCD(Dumbbell Nebula, NGC 6853)Science studies to date at NOAO usingLBNL CCDs:Blue is H-alphaGreen is SIII 9532Red is HeII 10124.

Science Goals F21

Integral Field Unit Spectrograph DesignSlit PlaneDetectorCameraPrismCollimatorSNAP Design:

Spectrograph architecture

Integral field spectrograph

Wavelength coverage

350-1700nm

Spatial resolution of slicer

0.12 arcsec

Field-of-View

2 x 2

Detector Architecture

1k x 1k, HgCdTe

Detector Array Temperature

130 - 140 K

Throughput

35%

Read Noise

4 e- (multiple samples)

Dark Current

1 e-/min/pixel

What makes the SN measurement special?Control of systematic uncertaintiesImagesSpectraRedshift & SN PropertiesLightcurve & Peak BrightnessdataanalysisphysicsM and L Dark Energy PropertiesAt every moment in the explosion event, each individual supernova is sending us a rich stream of information about its internal physical state.

Time Series of Spectra = SN CAT Scan

Lightcurves and Spectra from SNAP Goddard/Integrated Mission Design Center study in June 2001: no mission tallpoles

Goddard/Instrument Synthesis and Analysis Lab. study in Nov. 2001: no technology tallpoles

Supernova Requirements

Advantages of Space

Science ReachKey Cosmological Studies Type II supernova Weak lensing Strong lensing Galaxy clustering Structure evolution Star formation/reionization --

SNAP: The Third Generation

Dark Energy Equation of State

Precision CosmologyTegmarkSNAP

Primary Science Mission IncludesWeak lensing galaxy shearobserved from space vs. groundBacon, Ellis, Refregier 2000

And Beyond10 band ultradeep imaging survey Feed NGST, CELT (as Palomar 48 to 200, SDSS to 8-10m)Quasars to z=10 GRB afterglows to z=15 Galaxy populations and morphology to coadd m=32 Galaxy evolution studies, merger rateStellar populations, distributions, evolutionEpoch of reionization thru Gunn-Peterson effectLow surface brightness galaxies in H band, luminosity function Ultraluminous infrared galaxiesKuiper belt objectsProper motion, transient, rare objects

SNAP CollaborationG. Aldering, C. Bebek, W. Carithers, S. Deustua, W. Edwards, J. Frogel, D. Groom, S. Holland, D. Huterer*, D. Kasen, R. Knop, R. Lafever, M. Levi, E. Linder, S. Loken, P. Nugent, S. Perlmutter, K. Robinson (Lawrence Berkeley National Laboratory)E. Commins, D. Curtis, G. Goldhaber, J. R. Graham, S. Harris, P. Harvey, H. Heetderks, A. Kim, M. Lampton, R. Lin, D. Pankow, C. Pennypacker, A. Spadafora, G. F. Smoot (UC Berkeley)C. Akerlof, D. Amidei, G. Bernstein, M. Campbell, D. Levin, T. McKay, S. McKee, M. Schubnell, G. Tarle , A. Tomasch (U. Michigan) P. Astier, J.F. Genat, D. Hardin, J.- M. Levy, R. Pain, K. Schamahneche (IN2P3)A. Baden, J. Goodman, G. Sullivan (U.Maryland)R. Ellis, A. Refregier* (CalTech)A. Fruchter (STScI)L. Bergstrom, A. Goobar (U. Stockholm)C. Lidman (ESO)J. Rich (CEA/DAPNIA)A. Mourao (Inst. Superior Tecnico,Lisbon)

12 institutions, ~50 researchers

SNAP at the American Astronomical Society Jan. 2002 MeetingOral Session 111. Science with Wide Field Imaging in Space:The Astronomical Potential of Wide-field Imaging from Space S. Beckwith (Space Telescope Science Institute)Galaxy Evolution: HST ACS Surveys and Beyond to SNAP G. Illingworth (UCO/Lick, University of California)Studying Active Galactic Nuclei with SNAP P.S. Osmer (OSU), P.B. Hall (Princeton/Catolica)Distant Galaxies with Wide-Field Imagers K. M. Lanzetta (State University of NY at Stony Brook)Angular Clustering and the Role of Photometric Redshifts A. Conti, A. Connolly (University of Pittsburgh)SNAP and Galactic Structure I. N. Reid (STScI)Star Formation and Starburst Galaxies in the Infrared D. Calzetti (STScI)Wide Field Imagers in Space and the Cluster Forbidden ZoneM. E. Donahue (STScI)An Outer Solar System Survey Using SNAPH.F. Levison, J.W. Parker (SwRI), B.G. Marsden (CfA)

Oral Session 116. Cosmology with SNAP:Dark Energy or WorseS. Carroll (University of Chicago)The Primary Science Mission of SNAPS. Perlmutter (Lawrence Berkeley National Laboratory)SNAP: mission design and core survey T. A. McKay (University of Michigan Sensitivities for Future Space- and Ground-based SurveysG. M. Bernstein (Univ. of Michigan)Constraining the Properties of Dark Energy using SNAPD. Huterer (Case Western Reserve University)Type Ia Supernovae as Distance Indicators for CosmologyD. Branch (U. of Oklahoma)Weak Gravitational Lensing with SNAPA. Refregier (IoA, Cambridge), Richard Ellis (Caltech)Strong Gravitational Lensing with SNAPR. D. Blandford, L. V. E. Koopmans, (Caltech)Strong lensing of supernovaeD.E. Holz (ITP, UCSB)

Poster Session 64. Overview of The Supernova/Acceleration Probe:Supernova / Acceleration Probe: An Overview M. Levi (LBNL)The SNAP TelescopeM. Lampton (UCB)SNAP: An Integral Field Spectrograph for SN IdentificationR. Malina (LAMarseille,INSU), A. Ealet (CPPM)SNAP: GigaCAM - A Billion Pixel ImagerC. Bebek (LBNL)SNAP: Cosmology with Type Ia SupernovaeA. Kim (LBNL)SNAP: Science with Wide Deep FieldsE. Linder (LBNL)

Resource for the Science Community SNAP main survey will be 4000x larger (and as deep) than the biggest HST deep survey, the ACS survey

Complementary to NGST: target selection for rare objects

Can survey 1000 sq. deg. in a year to I=29 or J=28 (AB mag)

Archive data distributed

Guest Survey Program

Whole sky can be observed every few months

Galaxy populations and morphology to coadded m=31 Quasars to redshift 10 Epoch of reionization through Gunn-Peterson effect Lensing projects: Mass selected cluster catalogs Evolution of galaxy-mass correlation function Maps of mass in filaments

Two GSFC scientists at both the DoE preview and SAGENAP.