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The Carnegie Supernova Project. Wendy Freedman Carnegie Observatories Cosmology 2007 San Servolo, Italy August 30, 2007. State of the Art (2007): Type Ia Supernovae. HST ACS data. Knop et al. 2003. Riess et al. 2004. Astier et al. 2006. Wood-Vasey et al. 2007. WLF et al. 2007.
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The Carnegie Supernova Project Wendy Freedman CarnegieObservatories Cosmology 2007 San Servolo, Italy August 30, 2007
State of the Art (2007): Type Ia Supernovae HST ACS data Knop et al. 2003 Riess et al. 2004 Astier et al. 2006 Wood-Vasey et al. 2007 WLF et al. 2007
Carnegie Supernova Project: Primary Goals • Reduce systematics (reddening, calibration, K-corrections…) • I-band restframe Hubble diagram => observations in the near-IR (>1m) “Y” , J bands (To date only UBV restframe…)
Carnegie Supernova Project Swope 1-meter Dupont 2.5-meter Magellan 6.5-meter Low z: High z: • u’BVg’r’i’YJHKphotometry • 2.5-meter spectroscopy • YJ photometry • Magellan 6.5-meter • ~100 SNe Ia at completion • observations near max • 0.2 < z < 0.8 • C40 9 month campaigns • over 5 years (1350 nights) • densely sampled photometry • and spectroscopy 0 < z < 0.1 • 100 SNe Ia, 100 SNe II
Carnegie Supernova Project (CSP) Chris Burns Carlos Contreras Gaston Folatelli Wendy Freedman (PI, High z) Mario Hamuy Barry Madore Nidia Morell Eric Persson Mark Phillips (PI, Low z) Miguel Roth Nick Suntzeff Pamela Wyatt Collaborators: Ray Carlberg, Chris Pritchet, Mark Sullivan, Kathy Perrett, Andy Howell (CFHT SN Legacy) Alex Filippenko, Weidong Li (LOSS) Nick Suntzeff (ESSENCE) Josh Friemann, Masao Sato (SDSS-II) Dan Kelson, Eric Hsiao http://www.ociw.edu/csp/
CSP Collaborations High z: Low z: • CFHT Legacy Survey • ESSENCE • LOTOSS (KAIT) • SN Factory Intermediate z: • SDSS-II CSP followup and collaboration
Carnegie Supernova Project: Systematics Minimize effects due to: • Galactic reddening • Host reddening • Supernova Dust • Reddening • K-corrections • Environment • Calibration** Overview: WLF 2005, astro-ph/0411176 Nugent et al (2002)
1. Galactic Extinction Law AU / E(B-V)= 4.9 U AB / E(B-V)= 4.1 B V AI / E(B-V) = 1.7 I R V = AV / E(B-V) Cardelli, Clayton and Mathis 1989
2. Improved K-corrections Eric Hsiao Univ. Victoria astro-ph 0703529 Thesis: Improvement to Standard (Nugent) K-corrections New spectra, at many epochs and including i-band coverage (including CSP low-z data). CSP { Ca triplet
CSP Low z Targets Low z supernovae
Carnegie Supernova Project • SN 2006X • NGC 4321 • (M100) • Type Ia • Spectra from • du Pont and • Magellan / • LDSS2 SN2006X Nidia Morell
Magellan High-z IR Observations: Two Examples d149wcc4_11 (ESSENCE) z ~ 0.3 c040117-14 (CFHT Legacy) z ~ 0.6 Target Template Difference
Carnegie Supernova Project: High z SNLS SDSS-II ESSENCE • 58 SN Ia • as of 3/07 • 41 with • templates • 16 with complete reductions, reddenings Number Redshift z
Carnegie Supernova Project: High z i’-band light curves: low z • High z: • Observe pre- • maximum • Follow 3-7 • epochs • Less than 10 days after maximum • Gaps less than • 5 days 1st peak 2ndpeak Redshift
Carnegie Supernova Project: High z J z = 0.59 z = 0.62 Y z = 0.32 gri : SDSS-II Y: Magellan . i r Y z = 0.52 z = 0.43 i . z = 0.62 ri: SNLS YJ: Magellan r g C. Burns
Carnegie Supernova Project: High z • Use optical data to • determine decline • rates (m15(B) ). • Use both optical and • near-IR data to • solve for reddening. • Use YJ light curves • to solve for the • distance modulus. YJ . Template light curves from Prieto et al. (2006) nearby sample
Carnegie Supernova Project: High z *PRELIMINARY* 16 Type Ia supernovae First I-band Hubble diagram at z > 0.07 Riess et al. gold Astier et al. Magellan • small scatter at I • better than current • low-z sample Redshift
Carnegie Supernova Project: Fisher-Matrix Constraints on wo and Current CSP (50 SN Ia) 100 SN Ia 150 SN Ia Stage I SNLS (71 SN Ia) Astier et al (2006) Chris Burns WMAP plus H0 Key Project priors 95% confidence contours CSP Allows for k-correction and color errors**
Carnegie Supernova Project: Fisher-Matrix Constraints on wo and Current CSP (50 SN Ia) 100 SN Ia 150 SN Ia Stage II SNLS (700 SN Ia) Chris Burns WMAP plus H0 Key Project priors 95% confidence contours
Carnegie Supernova Project: High z *PRELIMINARY* maximum likelihood CSP+BAO: M = 0.3 ± 0.1 w = -0.9 ± 0.2 95% confidence • Assumption: • flat universe W = P /
SNe Ia & The GMT 0.5 seeing HST 1.5m GMT AO SNe studies are limited by confusion GMT AO will address this GMT Science Working Group --P. McCarthy
The Giant Magellan Telescope (GMT) • Alt-az structure • Seven 8.4-m primary mirrors • Cast borosilicate honeycomb • 25.3-m enclosed diameter • 24.5-m diffraction equivalent • 21.5-m equivalent aperture • 3.2-m adaptive Gregorian secondary mirror
GMT Institutions • Australia • Carnegie Observatories • Harvard University • Smithsonian Astrophysical Observatory • Texas A&M University • University of Arizona • University of Michigan • University of Texas, Austin • + …OTHERS TBD
Summary • First restframe I-band Hubble diagram for 0.2 < z < 0.7 • Dispersion lower than for UBV • Lower sensitivity to reddening • Improved K-corrections • Preliminary Results: w = -0.9§ 0.2 (95% confidence) • Final sample 4-5 times greater • Low redshift : tests of systematics • High redshift: I-band Hubble diagram • “Local” calibration for JDEM