The Carnegie Supernova Project

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The Carnegie Supernova Project
Wendy Freedman Carnegie Observatories Cosmology
2007 San Servolo, Italy August 30, 2007
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State of the Art (2007) Type Ia Supernovae
HST ACS data
Riess et al. 2004
Knop et al. 2003
Astier et al. 2006
Wood-Vasey et al. 2007
WLF et al. 2007
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Carnegie Supernova Project Primary Goals

• Reduce systematics (reddening, calibration,
  K-corrections)
• I-band restframe Hubble diagram
• gt observations in the near-IR (gt1?m)
• Y , J bands
• (To date only UBV restframe)

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Carnegie Supernova Project
Swope 1-meter
Magellan 6.5-meter
Dupont 2.5-meter
Low z
High z

• uBVgriYJHK photometry
• 2.5-meter spectroscopy

• YJ photometry
• Magellan 6.5-meter

• 100 SNe Ia at completion
• observations near max
• 0.2 lt z lt 0.8

• C40 9 month campaigns
• over 5 years (1350 nights)
• densely sampled photometry
• and spectroscopy 0 lt z lt 0.1
• 100 SNe Ia, 100 SNe II

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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/
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CSP Collaborations
High z
Low z

• CFHT Legacy Survey
• ESSENCE

• LOTOSS (KAIT)
• SN Factory

Intermediate z

• SDSS-II

CSP followup and collaboration
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Carnegie Supernova Project Systematics
Minimize effects due to

1. Galactic reddening
2. Host reddening
3. Supernova Dust

• Reddening
• K-corrections
• Environment
• Calibration

Overview WLF 2005, astro-ph/0411176
Nugent et al (2002)
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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
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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
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CSP Low z Targets
Low z supernovae
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Examples of CSP Low-z Light Curves
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Carnegie Supernova Project

• SN 2006X
• NGC 4321
• (M100)
• Type Ia
• Spectra from
• du Pont and
• Magellan /
• LDSS2

SN2006X
Nidia Morell
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Magellan High-z IR Observations Two Examples
d149wcc4_11 (ESSENCE) z 0.3
c040117-14 (CFHT Legacy) z 0.6
Target
Template
Difference
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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
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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
2nd peak
Redshift
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Carnegie Supernova Project High z
J
z 0.59
z 0.62
z 0.32 gri SDSS-II Y Magellan
Y
.
i
r
Y
z 0.43
z 0.52
i
.
z 0.62 ri SNLS YJ Magellan
r
g
C. Burns
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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.

Y J
.
Template light curves from Prieto et al. (2006)
nearby sample
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Carnegie Supernova Project High z
PRELIMINARY 16 Type Ia supernovae First
I-band Hubble diagram at z gt 0.07
Riess et al. gold Astier et al.
Magellan

• small scatter at I
• better than current
• low-z sample

Redshift
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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
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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
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Carnegie Supernova Project High z
PRELIMINARY
maximum likelihood CSPBAO ?M 0.3 0.1  w
  -0.9   0.2 95 confidence

• Assumption
• flat universe

W P / ?
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SNe Ia The GMT
0.5?? seeing HST 1.5?m GMT AO
SNe studies are limited by confusion GMT AO will
address this
GMT Science Working Group --P. McCarthy
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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

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GMT Institutions

• Australia
• Carnegie Observatories
• Harvard University
• Smithsonian Astrophysical Observatory
• Texas AM University
• University of Arizona
• University of Michigan
• University of Texas, Austin
• OTHERS TBD

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Summary

• First restframe I-band Hubble diagram for 0.2 lt z
  lt 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

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