Supernova Cosmology / Dark Energy Program

Saul Perlmutter

Mar 2, 2006

SN

factory

SNLS

Baryon Osc.

SNAP

HST

Cluster SN

SCP PersonnelCurrent Collaborators

UC DavisU FloridaMichigan StateU MichiganVanderbilt USTScI/Johns HopkinsCarnegie ObservatoriesJPL ESOIN2P3/Paris Stockholm UU Oxford U TokyoU TorontoU Victoria…

SCP FTE

Faculty/Senior staffS. Perlmutter 0.50M. Strovink 0.17G. Goldhaber (ret) 0.05

Division FellowD. Schlegel 0.33

StaffG. Aldering 0.20A. Spadafora 1.00

Term/Post docM. Kowalski 1.00K. Dawson 0.50 (0.50 SNAP)V. Fadeyev (1.00 SCP on NASA grant)N. Suzuki (1.00 SCP on NASA grant)N. Kuznetsova (SNAP with SCP analysis)

TOTAL STAFF FTE 3.75

Grad StudentsK. BarbaryD. Rubin

SCP LBNL Funding ($K)

FY04 Actual

FY05 Actual

FY06 Lab plan

FY07 Pres Req

M&S 320 163 197

SWF 893 842 1036

Total 1213 1005 1233 1037

Apply CMAGIC to high redshift SNe

A. Conley, PhD thesis. March 2005

• Alternative method provides systematic cross check of previous results

• SCP + literature SNe • 21 high z, 31 low z

• Cosmology fit done as blind analysis - conceal final results while developing analysis

Cosmological Parameters

A. Conley, et al., ApJ accepted for pub.

astro-ph/0602411

SuperNova Legacy Survey at CFHT

• Started March '03.

• 40 (d) nights/year for 5 years

• 4 square degrees : u’, g’, r’, i’, z’

• g’,r’,i’,z’ every 2-3 nights for 10 months/yr

• 15’, 30’, 1h, 30’

• Detection up to z = 1.2 -1.3

• Multicolor LC follow- up up to z=0.9

• 2000 SN Ia + 2000 SN II ? + AGNs ? + ..

• 600 well measured SNIa 0.3<z<0.9

SuperNova Legacy Survey at CFHT

SNe Ia Spectra from Keck

Spectra of some of the SNLS SN candidates obtained during the 2005A Keck LRIS observing campaign. The light-blue lines show the data after host galaxy subtraction (if necessary),rebinned to 10Å. Overplotted in black are the best fit SN templates. The spectra are confirmed by Keck to be Type Ia SNe.

Data from LBL group:KowalskiSchlegelPerlmutter Aldering

Keck Remote Observing Room at LBL

First-year results from SNLS

Hubble diagram of SNLS and nearby SNe Ia, with various cosmologies superimposed. The bottom plot shows the residuals for the best fit to a flat cosmology.

The Supernova Legacy Survey: Measurement of M, and w from the First Year Data Set

P. Astier, et al., A&A 447, 31 (2006)

71 high redshift type Ia supernovae

First-year results from SNLS

Contours at 68.3%, 95.5% and 99.7% confidence levels for the fit to an (M, L ) cosmology from the SNLS Hubble diagram(green contours), the SDSS baryon acoustic oscillations(Eisenstein et al. 2005, blue), and the joint confidence contours (red).

Contours at 68.3%, 95.5% and 99.7% confidence levels for the fit to a flat (M, w) cosmology, from the SNLS Hubble diagram alone, from the SDSS baryon acoustic oscillations alone (Eisenstein et al. 2005), and the joint confidence contours.

HST/SCP

Knop et al (ApJ, 2003)

Before Extinction Correction

After Extinction Correction

Sullivan, et al. (2003)

Decelerating and Dustfree: Targeting SNe in Very High Redshift Galaxy Clusters

• Major 219-orbit year-long HST Program in progress in collaboration with several galaxy cluster groups

• searching ~ 24 massive galaxy clusters at z > 1 with ACS

• Why clusters?

• Dominated by nearly dust-free early type galaxies.

• 5 times higher density of early type galaxies

• SNe in these galaxies have negligible dust extinction

• Our Program

• image clusters with cadence ~ 20-23 day in z’, i’ bands

• follow SNe with NICMOS (J band)

• spectroscopy: 20 half-nights on Subaru, ~ 4 nights on Keck

• Scientific goals

• Significantly improve SN constraints of dark energy - statistical and systematic uncertainties

• Cluster studies: weak lensing, galaxy morphology, and color-magnitude relationship.

(a) Left Panel: Simulated 68% confidence region on w' vs. w0 for the current literature SN sample but with underlying cosmology(w0 = -1; w’ = 0). The parameters are poorly constrained because color errors are magnified by RB ~ 4.

(b) Middle Panel: The solid red contour shows reduced uncertainties (excluding systematic bias) using a Bayesian prior on the extinction distribution prior to suppress color errors.The filled gray contour is from Riess et al. 2004 using this prior. The short-dashed contour shows that this approach is also sensitive to shifts in RB with redshift; the example shifts from 4.1to 2.6.

(c) Right Panel: The goal of this project is shown as a confidence region for a simulated new sample of 10 z > 1 SNe Ia found in cluster ellipticals, together with 5 in ellipticals from the past and ongoing GOODS searches, as well as 120 SNe Ia in ellipticals at the lower redshifts now being produced by the ground-based CFHT SN Legacy Survey, the CTIO Essence survey, and (at z < 0.1) the Nearby SN Factory

SNe in Very High Redshift Galaxy Clusters

Discovering SNe in high redshift galaxy clusters

11 SNe discovered to date:

3 z ≥ 1 in cluster ellipticals

1 z > 1 in cluster spiral

2 z > 1 in field ellipticals

4 z < 1 in field spirals

1 possible SN z > 1.5

LBL group operations:

With less than 1-day turn-around:

• Obtain HST/ACS images of ~ 4 clusters/week, within hours of the observations

• Run through LBL pipeline, scan candidates

• Decide NICMOS, spectroscopy followup

First SN discovered in a cluster in this search

Cluster RCS0221-03 at z = 1.02

Host was cataloged Cluster member.

SN Type: Ia

SN redshift

Spectrum taken for confirmation.

ACS z bandACS I bandNicmos J band

preliminary

Intensive ground-based spectroscopy follow-up

Goal: Establish Supernova type and redshift

• Subaru: 10 half-nights/semester

• Keck: 2 nights/semester

• VLT: 10 hours/semester (queue mode) + Director’s Discretionary time

• UCSC collaborators obtained Keck IR image of our z = 1.3 SN using adaptive optics. (J. Melbourne et al., AAS, 2006)

Preliminary VLT spectrum of SN Ia at z=1.02 in RCS0221-03 cluster

Preliminary SN lightcurves

Summary of recent SCP Accomplishments: high redshift SN studies

• Major new results:

– Cosmological parameters using new CMAGIC technique published

– SNLS - cosmological parameter from first-year dataset published

– Large HST program underway with collaborators studying galaxy clusters

• Important data sets completed, analysis in progress:

– Published spectroscopy for large high-redshift SN data set in 2 papers (and data released on web page)

– ~40 SNe from Subaru/HST (0.8 < z < 1.5)

– final reference images obtained on other SN datasets

Spectra of High Redshift Type Ia Supernovae and a Comparison with their Low Redshift Counterparts

I. M. Hook, et al., AJ, 130, 2788 (2005) , astro-ph/0509041 (data release on SCP web page).

The time sequence of high redshift SN spectra in order of rest-frame date relative to maximum light as determined from the light curve. Spectra of the nearby Type Ia, SN 1992A are interspersed for comparison.

We find no evidence for evolution in SN Ia properties between low and high redshift samples.

Spectra of high redshift SNe Ia

SCP SN studies using Subaru 8.2m

• Intensive SN search with Subaru/ Suprime-Cam in 2002

– 5 nights in Spring/11 nights in Fall

– coordinated spectroscopy with Keck, Gemini, and VLT

• Widest field imaging camera on an 8-10m class telescope

– FOV of 33 x 26 arcmin. Candi-dates

Spectrum SNe Spec. Confirmed SNe Ia

HST

Spring 01 22 8 7 3 1

Spring 02 55 13 7 5 4

Fall 02 44 22 25 5 3

Total 121 48 39 13 8

Spectroscopy Obtained

S. Perlmutter, G. Goldaber, K. Dawson, V. Fadeyev, D.Schlegel, A. Spadafora, N. Suzuki, Tokyo group

Un-typed SNe

SNe Ia

Adding SNe to Hubble diagram at the highest redshifts

SCP Subaru data will provide a significant SN sample at z > 1.

Spectra of host galaxies obtained in fall 2005 provide redshift information needed to complete this analysis.

Summary of recent SCP Accomplishments: low redshift SN studies

• SCP Low-z campaign

– Detailed analysis of spectra of 2 SNe published (and data released on web page)

– Lightcurves obtained from cross-calibrating telescopes used in extensive observing campaign

• Other studies of systematics

– Polarization: surprising correlation with the width-brightness relationship (L. Wang)

– Nonlinear Decline-Rate Dependence and Intrinsic Variation of Type Ia Supernova Luminosities (M. Strovink, L. Wang, et al.)

– First Restframe I-band Hubble diagram published

Polarization versus lightcurve timescale

slow fast

Wang, et al. submitted

SCP 1999 Low-z SN campaign

SN 1999aa

SN 1999ac SN 1999ao

SN 1999awSN 1999bp

Lightcurves - Cross calibration of multiple telescopes

—20 nearby SN observed (0.02 < z < 0.24)— ~2600 images in UBVRI—17 different instruments

M. Kowalski, B. Farris

Detailed spectroscopic studies of 2 SNe• Spectroscopic Observations and

Analysis of the Peculiar SN 1999aa G. Garavini et al., AJ 128, 387 (2004)

High S/N spectra allow for identification and temporal evolution of intermediate mass elements

• Spectroscopic Observations and Analysis of the Unusual Type Ia SN 1999ac

G. Garavini et al., AJ, 130, 2278 (2005)

SN 1999aa

SN 1999ac

Synthetic spectrum (SYNOW) compared with SN 1999ac spectrum for day -15

1. Measurement of , from a blind analysis of Type Ia supernovae with CMAGIC: Using color information to verify the acceleration of the Universe., Conley, A., et al., accepted for publication in ApJ, astro-ph/0602411 (2006)

2. Nonlinear Decline-Rate Dependence and Intrinsic Variation of Type Ia Supernova Luminosities, Wang, L., Strovink, M., Conley, A., Goldhaber, G., Kowalski, M., Perlmutter, S., & Siegrist, J., accepted for publication in ApJ, astro-ph/0512370 (2005).

3. Photometric Selection of High-Redshift Type Ia Supernova Candidates, Sullivan, M., et al., AJ, 131, 960 (2006).

4. SNLS: Measurement of , , and w from the First Year Data Set, Astier, P., et al., A&A, 447, 31 (2006)

5. Spectra of High-Redshift Type Ia Supernovae and a Comparison with their Low-Redshift Counterparts. Hook, I. M., et al., AJ, 130, 2788 (2005).

6. Spectroscopic confirmation of high-redshift supernovae with the ESO VLT., Lidman, C., et al., A&A, 430, 843 (2005).

7. Spectroscopic Observations and Analysis of the Unusual Type Ia SN 1999ac, Garavini, G., et al., AJ, 130, 2278 (2005).

8. Restframe I-band Hubble diagram for type Ia supernovae up to redshift z ~ 0.5, Nobili, S., et al., A&A, 437, 789 (2005).

9. Gemini Spectroscopy of Supernovae from the Supernova Legacy Survey: Improving High-Redshift Supernova Selection and Classification, Howell, D. A., et al., ApJ, 634, 1190 (2005).

SCP Publications in past year (1)

10. A Definitive Measurement of Time Dilation in the Spectral Evolution of the Moderate-Redshift Type Ia Supernova 1997ex, Foley, R. J., Filippenko, A. V., Leonard, D. C., Riess, A. G., Nugent, P., & Perlmutter, S., ApJ, 626, L11 (2005).

11. Dust around Type Ia Supernovae, Wang, L., ApJ, 635, L33 (2005).

Presentations and Posters at Jan 2006 AAS Meeting

• Decelerating and Dustfree: Targeting SNe in Very High Redshift Galaxy Clusters, Dawson, K. S., et al., AAS, 207, (2005).

• SNLS: Supernova Rise Times from the SNLS Sample, Conley, A., et al., AAS, 207, (2005).

• SNLS: Constraints on SN Ia progenitors from host galaxies, Howell, D. A., et al., AAS, 207, (2005).

• SNLS: Type Ia Supernova Rates from the SNLS Survey: the Connection with Morphology and Star Formation Rate, Pritchet, C. J., et al., AAS, 207, (2005).

• SNLS: The Supernova Type Ia Rate at z = 0.47, Neill, J. D., et al., AAS, 207, (2005).

• SNLS: Relating the properties of type Ia supernovae to the stellar populations of their host galaxies, Sullivan, M., et al., AAS, 207, (2005).

• SNLS: Empirical modeling of distant supernovae, Guy, J., et al., AAS, 207, (2005).

PhD Thesis:

Estimation of the Cosmological Parameters from an Analysis of Type Ia Supernovae with CMAGIC, A. Conley (UC Berkeley) 2005

SCP Publications in past year (2)

Near Term Goals

• Ongoing Observing Program– SNLS

• Continue with spectroscopy observations and analysis • Unparalleled sample for cosmology and systematics analysis

– Major HST SN galaxy cluster program in progress • studying dust-free SNe in very high redshift galaxy clusters to

constrain dark energy in the epoch of deceleration• Current run extends through Aug ‘06. Have proposed to continue this

for a second year

• Analysis and publication of recently completed datasets– Subaru dataset - large sample z > 1 SNe

– Albinoni - a well-measured SN Ia at z=1.2

– Low-z data set

Long-term ScenariosBefore SNAP/JDEM• Large SCP programs continue

– SNLS– HST program– Subaru program– Farther in future: Dark Energy Survey

• Strategic planning exercise – now underway for our dark energy program leading up to JDEM including supernova

cosmology and other approaches

• Resources needed:– additional postdoc(s), graduate students to make best use of new data for cosmology studies– instrumentation development for next programs

Next: SNAP/JDEM!

Dark Energy Survey Overview

• DES Science Goals: Study dark energy with four techniques

– Galaxy cluster surveys (with SPT)– Weak lensing– Galaxy angular power spectrum– SN Ia distances

• Instrument and schedule– New 3 deg2 camera on the Blanco

4m on Cerro Tololo– Construction: 2004-2009– Survey Operations: 2009-2013– Precursor to SNAP, LSST

• Two linked, multiband surveys– 5000 deg2 g’, r’, i’ and z’– Repeated observations of 40 deg2

– Catalogs made available to community after one year

Image credit: Roger Smith/NOAO/AURA/NSF

Blanco 4m Telescope on Cerro Tololo

Internal Assessments: SCPSummary of comments from the LBNL Director’s Review (Nov 05)

• The Division has a strong supernova cosmology program with several distinct but related projects. The LBNL team played a key role in motivating the scientific case for JDEM and heads the SNAP proposal.

• …LBNL scientists are continuing to advance the use of Type Ia supernovae as a fundamental yardstick with which to measure this expansion. They have paid appropriate attention to the role of systematic uncertainties in the derivation of cosmological parameters from the supernova data, and have devised a number of distinct programs to address these systematic uncertainties, using both low-redshift and moderate-redshift supernova samples. The LBNL group continues to lead the world in this field.

• …The group is active in the analysis of data from the Supernova Cosmology Project (SCP), in the collection of data with the Nearby Supernova Factory and the SN Legacy Survey at the Canada-France-Hawaii Telescope, in the analysis of Hubble Space Telescope data, and in detector R&D for the SNAP proposal. The eleven SCP publications in the last year represent a healthy physics output. Members of the Committee were pleased to hear that, in the application of CMAGIC to high redshift SNe in the SCP and in the literature, the cosmology fit was done as a blind analysis. As cosmology becomes a precision science, such efforts to minimize (unintentional) experimenters’ bias are very important.

Internal Assessments: SCP (con’t)Summary of comments from the LBNL Director’s Review (Nov 05)

• The majority of Division staff members who are working on SNAP are also engaged in the ground-based supernova program, and thus they are still involved in fruitful scientific research while waiting for JDEM to move forward.

• LBNL continues to provide a strong re-training ground for particle-physics PhDs interested in moving into supernova science and cosmology. However, the training of such postdocs provides particular and unique challenges,

some of which were raised in last year's report …. We recommend that further efforts be made to connect these postdocs with students, postdocs, and professors on campus (particularly in astronomy) who work on related issues and use similar observational techniques.

SNAP co-PI’s: Perlmutter & Levi

SNAP:SuperNova

Acceleration Probe

A multidimensional parameter space: Clustering of physically significant observables

SNAP: Observing supernovae withlightcurves and spectra

SNAP SurveysSNAP Surveys

Synergy of Supernovae + Weak Lensing

• Comprehensive: no external priors required!

• Independent test of flatness to 1-2%

• Complementary (SNe + WL only): conservative:

w0 to ±0.05, variation w to ±0.12 (with systematics) modelw0 to ±0.03 variation w to ±0.06 (with systematics)

SUGRA modelAdding panoramic survey and better systematics:

w0 to ±0.03, variation w to ±0.06 (with systematics) modelw0 to ±0.015 variation w to ±0.03 (with systematics)

SUGRA model

• Flexible: Panoramic is available if improved systematics in space warrant greater than 1000 sq. deg.

Survey Area(sq.deg) Depth(AB mag) ngal(arcmin-2) Ngal

Deep/SNe 15 30.3 250 107

Wide 1000 28.0 100 108.5

Panoramic 7000-10000 26.7 40-50 109

Baryon Oscillations:

would need R > ~250 to do the radial Baryon Oscillations, but get tangential Baryon Oscillations for free with Wide or Panoramic Survey

SN

factory

SNAP

Baryon Osc.

WMAP

Tegmark, Oliveira-Costa, Hamilton (2003)

SDSS

SN

factory

SNLS

Baryon Osc.

SNAP

HST

Cluster SN