The Accelerating Universe Probing Dark Energy with Supernovae Eric Linder Berkeley Lab

Evidence for Acceleration Supernovae Ia:  DE, w=p/ , w´=dw/dz Observation -- Magnitude-redshift relation Age of universe: Contours of t 0 parallel CMB acoustic peak angle: t 0 =14.0±0.5 Gyr [Flat universe, adiabatic perturbations] CMB Acoustic Peaks: Substantial dark energy, e.g <   < 0.74 [Small GW contribution, LSS, H 0 ] Large Scale Structure: Power spectrum P k, Growth rate, “looks” [simulations]

Supernova Cosmology

A Dark Energy Universe Tyson

Correlation of Age with CMB Peak Angle Knox 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 Coverage Wright Nov ‘01 Jan ‘02 Apr ‘02Oct ‘02 Wright

Supernova 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. Dark Energy Credit STScI

Dark Energy Theory 1970s – 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 swan Lensing   = Chiba & Yoshii Supernovae   = SCP, HiZ Ly  Forest   = D. Weinberg et al.

 : Ugly Duckling Astrophysicist: Einstein equations –  g ab  p = -  Naturally,  =const=  PL   = Today    M Field Theorist: Vacuum – Lorentz invariant T ab ~  ab = diag { -1, 1, 1, 1}  p = -  Naturally, E vac ~ GeV E  ~ meV  =0? Fine Tuning Puzzle – why so small? Coincidence Puzzle – why now?

Scalar Field: Beautiful Swan Astrophysicist: Friedmann equations – (å/a) 2 =(8  /3)(  m +   ) ä/a=-(4  /3)(  m +   +3p  ) Field Theorist: Lagrangian – L =(1/2)  a   a  -V(  )  (1/2)  2 -V T ab =  a  b  - L g ab  =K+Vp=K-Vw=p/  = (K+V) / (K-V)  [-1, +1] Slow Roll (Inflation) K << V  p=-   w=-1 Free Field (kination) V << K  p=+   w=+1 Coherent Oscillations (Axions) =  p=0  w=0 (matter).

Fundamental Physics   (a) =   (0) e -3  dlna(1+w) ~ a -3(1+w) w(z)=w 0 +w’z Astrophysics  Cosmology  Field Theory r(z)  Equation of state w(z)  V(  ) V (  ( a(t) ) ) SN CMB etc. “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 Weinberg Is  =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 runaway Standard explosion from nuclear physics

1 Parameter Family Homogeneity

Hubble diagram – low z

Hubble diagram - SCP In flat universe:  M =0.28 [ .085 stat][ .05 syst] Prob. of fit to  =0 universe: 1% redshift z

Supernova Cosmology

Original Current (offset) Near Term Proposed Supernovae Probes - Generations

SNAP: The Third Generation

Dark Energy Equation of State

Hubble Diagram

Dark Energy Exploration with SNAP Current ground based compared with Binned simulated data and a sample of Dark energy models

Probing Dark Energy Models

From Science Goals to Project Design Science Measure  M and  Measure w and w (z) Data Set Requirements Discoveries 3.8 mag before max Spectroscopy with S/N=10 at 15 Å bins Near-IR spectroscopy to 1.7  m Statistical Requirements Sufficient (~2000) numbers of SNe Ia …distributed in redshift …out to z < 1.7 Systematics Requirements Identified and proposed systematics: Measurements to eliminate / bound each one to +/–0.02 mag Satellite / Instrumentation Requirements ~2-meter mirrorDerived requirements: 1-square degree imager High Earth orbit Spectrograph ~50 Mb/sec bandwidth (0.35  m to 1.7  m)

Mission Design

SNAP Survey Fields

GigaCAM, a one billion pixel array l Approximately 1 billion pixels l ~140 Large format CCD detectors required, ~30 HgCdTe Detectors l Larger than SDSS camera, smaller than H.E.P. Vertex Detector (1 m 2 ) l Approx. 5 times size of FAME (MiDEX) GigaCAM

Focal Plane Layout with Fixed Filters

Q1 Q2 Q3 Q4 Step and Stare and Rotation

High-Resistivity CCD’s New kind of CCD developed at LBNL Better overall response than more costly “thinned” devices in use High-purity silicon has better radiation tolerance for space applications The CCD’s can be abutted on all four sides enabling very large mosaic arrays Measured Quantum Efficiency at Lick Observatory (R. Stover):

LBNL CCD’s at NOAO See September 2001 newsletter at 1)Near-earth asteroids 2)Seyfert galaxy black holes 3)LBNL Supernova cosmology Cover picture taken at WIYN 3.5m with LBNL 2048 x 2048 CCD (Dumbbell Nebula, NGC 6853) Science studies to date at NOAO using LBNL CCD’s: Blue is H-alpha Green is SIII 9532Å Red is HeII 10124Å.

Science Goals – F21

Slit Plane Detector Camera Prism Collimator Integral Field Unit Spectrograph Design SNAP Design:

Images Spectra Redshift & SN Properties Lightcurve & Peak Brightness dataanalysisphysics  M and   Dark Energy Properties At every moment in the explosion event, each individual supernova is “sending” us a rich stream of information about its internal physical state. What makes the SN measurement special? Control of systematic uncertainties

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 Reach Key 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 Cosmology Tegmark NOW SNAP

Primary Science Mission Includes… Weak lensing galaxy shear observed from space vs. ground Bacon, Ellis, Refregier 2000

…And Beyond 10 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 rate Stellar populations, distributions, evolution Epoch of reionization thru Gunn-Peterson effect Low surface brightness galaxies in H’ band, luminosity function Ultraluminous infrared galaxies Kuiper belt objects Proper motion, transient, rare objects

SNAP Collaboration G. 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 Meeting Oral 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