The SuperNovae Legacy Survey Overview and First results

1
The SuperNovae Legacy Survey Overview and First
results
Sino-French workshop on Dark universe
Marseille, 23 Sep 2005

• Dominique Fouchez
• ( Centre de physique des Particules de Marseille/
  IN2P3 )
• On behalf of the SNLS Collaboration

2
The SNLS Overview and First results

• Introduction
• Project overview
• Current status and first results
• Perspectives

3
IntroductionThe cosmological paradigm

• Todays universe
• Dark matter (30) Dark energy (70)
• Dark energy
• caracterised by Equation of State
  wp/r
• w w(z)
• In the following w constant  

4
IntroductionThe principle of the measure

• Hubble diagram of standard candles
• Standard candles
• Redshift
• Magnitude
• Standard Candle
• Standardized Supernovae Ia
• Measure
• with a magnitude precision of few 0.01
• ? a precision of 0.1 for ltwgt
• will give first indication
• of Dark energy nature

5
Project a SuperNova Legacy Survey

• PRIMARY SCIENCE GOAL
  Measurement of cosmological parameters
• constraint ltwgt below the 0.1 precision
• ADDITIONAL GOALS
• Adressing all possible cosmological and
  astrophycical issues from such large SN set
• SN rate
• SN study,
• galaxy formation etc

6
Project Requirements

• 700 identified, localised, standardised and well
  measured high z SNIa
• Spectral identification of SN a maximum
  luminosity
• Spectral redshift from host galaxy and/or SN
  spectrum
• Multicolor LC Photometry g,r,i,z
• LC well sampled ( 5 multicolor epochs per month)
• Precise calibration   few percent accuracy
• depth, z0.3-0.9 (i at max lt 24.5 )

7
Project Requirements

• 700 identified, localised, standardised and well
  measured high z SNIa
• Spectral identification of SN a maximum
  luminosity
• Spectral redshift from host galaxy and/or SN
  spectrum
• Multicolor LC Photometry g,r,i,z
• LC well sampled ( 5 multicolor epochs per month)
• Precise calibration   few percent accuracy
• depth, z0.3-0.9 (i at max lt 24.5 )

8
Project Requirements

• 700 identified, localised, standardised and well
  measured high z SNIa
• Spectral identification of SN a maximum
  luminosity
• Spectral redshift from host galaxy and/or SN
  spectrum
• Multicolor LC Photometry g,r,i,z
• LC well sampled ( 5 multicolor epochs per month)
• Precise calibration   few percent accuracy
• depth, z0.3-0.9 (i at max lt 24.5 )

9
Project Requirements

• 700 identified, localised, standardised and well
  measured high z SNIa
• Spectral identification of SN a maximum
  luminosity
• Spectral redshift from host galaxy and/or SN
  spectrum
• Multicolor LC Photometry g,r,i,z
• LC well sampled ( 5 multicolor epochs per month)
• Precise calibration   few percent accuracy
• depth, z0.3-0.9 (i at max lt 24.5 )

10
Project Requirements

• 700 identified, localised, standardised and well
  measured high z SNIa
• Spectral identification of SN a maximum
  luminosity
• Spectral redshift from host galaxy and/or SN
  spectrum
• Multicolor LC Photometry g,r,i,z
• LC well sampled ( 5 multicolor epochs per month)
• Precise calibration   few percent accuracy
• depth, z0.3-0.9 (i at max lt 24.5 )

11
Project Requirements

• 700 identified, localised, standardised and well
  measured high z SNIa
• Spectral identification of SN a maximum
  luminosity
• Spectral redshift from host galaxy and/or SN
  spectrum
• Multicolor LC Photometry g,r,i,z
• LC well sampled ( 5 multicolor epochs per month)
• Precise calibration   few percent accuracy
• depth, z0.3-0.9 (i at max lt 24.5 )

12
Means
13
Means

• Team canadian-frenchothers (UKUSPort.)
• about 60 collaborators
• Telescope CFHTVLTGemini
• Time
• about 250H/year in both photometric and
  spectroscopic observations
• Real time detection pipelines

14
Means Telescopes intruments

• Photometry
• CFHT 3.6 meters at Hawaii
• megacam imager of 1 sq degree

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Means Telescopes intruments

• Spectrocopy 8m - class
• VLT FORS1
• Gemini GMOS
• Others KECK LRIS

16
Means Real time detection

• Principle of detection
• Subtraction of each night (stacked images) on a
  reference image to find individual detections

17
Means Real time detection

• Principle of detection
• Subtraction of each night (stacked images) on a
  reference image to find individual detections
• Construction of Lightcurve of candidates for all
  night all filter at same sky position

-

days
18
Means Real time detection

• Principle of detection
• Subtraction of each night (stacked images) on a
  reference image to find individual detections
• Construction of Lightcurve of candidates for all
  night all filter at same sky position
• SNIa photometric ranking to select candidate
  for spectroscopy follow up, based on multicolor
  lightcurve fit

19
Means Real time detection

• Principle of detection
• Subtraction of each night (stacked images) on a
  reference image to find individual detections
• Construction of Lightcurve of candidates for all
  night all filter at same sky position
• SNIa photometric ranking
• Two independant real time pipeline (Can F)
• crosscheck and robustness
• Select candidate for spectro after each obs night
  Result in less than 24H
• Dataflow stream up to 30 Go input/night and up
  to 10 To output/year

20
Means a fully automated pipeline
Detection on each stacked image Real time
science images (Elixir) provided by CFHT
automatically trigger the start of the pipeline.
Image stack subtraction is done to produce
individual detections detections are send to
event database for selection.
Detection on each stacked image

• Construction and selection of the candidated
• A manual stream (snlsdb), where a visual
  scanning is used to select and validate the
  snupernova candidates
• An automated selection (ACE), based on neural
  network trained on image simulation, is used to
  select the good candidates (better than 90
  efficient)

Construction and selection of the candidates
No human intervention is necessary up to this
stage to produce the candidate list.
Merging with the other (canadian) pipeline The
output of the pipeline is directed to the common
Canada/France candidate database (based at
Toronto) A synchronisation of the database is
performed each hour ( 90 agreement up to
i24.5). The choice of candidate for spectro is
made on the information collected by both French
and canada pipeline So far (july 2005) we
registred about 3000 candidates, 1000 SN like and
sent 330 of those to spectroscopy follow-up
21
Means a fully automated pipeline
Detection on each stacked image Real time
science images (Elixir) provided by CFHT
automatically trigger the start of the pipeline.
Image stack subtraction is done to produce
individual detections detections are send to
event database for selection.

• Construction and selection of the candidated
• A manual stream (snlsdb), where a visual
  scanning is used to select and validate the
  snupernova candidates
• An automated selection (ACE), based on neural
  network trained on image simulation, is used to
  select the good candidates (better than 90
  efficient)

No human intervention is necessary up to this
stage to produce the candidate list.
Merging with the other (canadian) pipeline The
output of the pipeline is directed to the common
Canada/France candidate database (based at
Toronto) A synchronisation of the database is
performed each hour ( 90 agreement up to
i24.5). The choice of candidate for spectro is
made on the information collected by both French
and canada pipeline So far (july 2005) we
registred about 3000 candidates, 1000 SN like and
sent 330 of those to spectroscopy follow-up
22
Status Real time lightcurves

• A sample of lighcurves in each filter

23
Status Spectroscopy

• 330 spectra analysed in quasi real time
• 190 Ia identified with template fitting
• Identification is
  performed by c2 fitting of SN database templates
• (different type Ia,
  Iapeculiar,Ic,IIP and different phase) and
  galaxy templates.

VLT
with SN and Galaxy fitted
24
Status Survey progress

• Almost 2 years of running

May 2005 800 SN like 190 SNIa
25
Status spectro redshift distribution

• Redshift distribution of SNIa ltzgt 0.6

26
First Results Cosmological parameters
measurement

• 1 year of data
• 142 spectra
• 20 Type II SNe
• 9 AGN/QSO
• 91 Sne Ia
• 10 miss references
• 6 only have 1 band
• Cosmo paramameters measurements 5 Steps
• Differential photometry
• Photometric calibration
• Lightcurve fit
• Cosmology fit
• Systematic uncertainties

75 usable SNIa events
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First result Differential photometry

• Image modelconstant galaxypoint source sky
  background

Fit is performed independently On each exposure
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First Results Lightcurve exemples
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First Results Multi-color lightcurve fits

• SALT Spectral adaptative lightcurve template
• Model SNIa SED as a function of
• Phase (date wrt to B-band maximum)
• Lambda (rest frame )
• Stretch (dilatation of B-band phase axis)
• Color (E(B-V) at B maximum)
• Color term and extinction
• Model fitted on an independant
• Sample of low z SNIa

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First results SNLS Lightcurve fits
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First results Photometric calibration

• Based on Landolt stars in landolt magnitude
  system
• Low redshift sample already in landolt
  magnitude
• Produce calibrated stars in SN field
• Checked observed vs synthetic color terms
• Zero points at the percent level

metric s
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First results Hubble diagram

• mB mB M a(s-1) bc
• 45 low z 71 SNLS ( outliers removed)

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First results Cosmological parameter fits

• SNLS first year contours, combined with Baryon
  oscillation results (Eisenstein et al 2005)

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Data consistency and systematic studies

• Comparison SNLS/Nearby stretch and color

(Black) (Blue)
stretch
color
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Data consistency and systematic studies

• SALT multi-band consistency
• DU3 is the difference between measure in a third
  band and expectation from SALT fit in two other
  band

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Data consistency and systematic studies

• Summary of error budget

37
First results numbers

• For a flat LCDM cosmology
• For a flat WM,w cosmology,
• Combined with Baryonic acoutic oscillation
  (Eisenstein 2005)

WM0.263 - 0.042 (stat) - 0.032 (syst)
WM 0.271 - 0.021 (stat) - 0.007 (syst) w
-1.023 - 0.090 (stat) - 0.054 (syst)
A better result than all ground-based SNe results
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Prospects
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Prospects error reduction

• The current status
• 71 high z SNIa
• sltwgt 0.1 (stat) 0.05 (syst)
• ? Important to control the systematical errors
  for error budget
• The perspectives
• Up to 700 high z SNIa
• Statistical error reduced
• Many analysis of systematical effect
• Systematical error better controlled and reduced
• Both Statistical and systematical errors can be
  reduced at the end of the survey

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Prospects Systematical errors control

• Systematical errors potential sources
• Calibration
• K correction
• Malmquist bias
• Evolution
• Dust
• Extinction
• Contamination
• Gravitational lensing

• Control tools and analysis
• Calibration program
• Multicolor lightcurves
• Spectral line studies
• Spectral evolution
• IR data
• UV studies
• Classification/Sub-sample studies
• Host galaxie morphology
• MonteCarlo simulations
• Type II analysis
• -

41
Prospects ultimate precision

• 5 years expectations sltwgt 0.07
• combined with low z SNe and
  weak lensing of CFHTLS

42
Prospects Other science

• Other science with 2000 Sne 1000 spectra
• SN rate
• SN IIP
• 
  
  ../..

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Prospects Other science
Type Ia rates Metallicity effects Type Ia progenitors Redshift evolution Cosmology with Type II SNe
SN Ia UV properties Properties of Dust Type Ia rise times Epoch of cosmic deceleration Ia explosion mechanism
Ia Intrinsic Scatter Benetti velocity diagram High-stretch SNe Ia diversity Core collapse SN rate CMAGIC
Core collapse progenitors Improved K-corrections SN Ib/c-GRB connection SN Ia peak-tail ratio Ia metallicity cutoff
Ia geometric effects II-P risetime IR Hubble Diagram Type IIn - Type Ia connection AGN/SN Ia connection
Ia pseudo-EW correlations Host galaxy properties Unique SNe Ia high velocity components SN color-color selection
SN Luminosity distribution Cosmic star formation history Deflagration vs. detonation Intrinsic Type Ia colors Type II shock breakout
Stretch, MLCS, ?m15 improvements Galactic chemical evolution Are SNe Ia a one parameter family? Are there low-s SNe Ia at high z? Groundwork for future (JDEM, LSST)
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Conclusions

• The SNLS project is entering its most existing
  phase of producing new science results
• Set up after first 2 years is well under control,
  in accordance to expectations should achived
  designed goal after 5 years
• First year result competitive with previous
  cosmological parameters measurements with SNIa
• The SNLS is a second generation High z SNIa
  project
• Very homegenous and complete dataset
• Redondancy of multicolor lighcurve and
  spectroscopy
• Systematical errors can be controlled and reduced
• The SNLS is a legacy survey
• Many other studies, related to SNe science will
  be possible
• Many scientific results to come Stay
  tuned !