Particules Élémentaires, Gravitation et Cosmologie Année ...
The SuperNovae Legacy Survey Overview and First results Dominique Fouchez ( Centre de physique des...
-
Upload
darlene-ramsey -
Category
Documents
-
view
214 -
download
1
Transcript of The SuperNovae Legacy Survey Overview and First results Dominique Fouchez ( Centre de physique des...
The SuperNovae Legacy Survey Overview and First results
Dominique Fouchez ( Centre de physique des Particules de Marseille/ IN2P3 )
On behalf of the SNLS Collaboration
Sino-French workshop on Dark universe Marseille, 23 Sep 2005
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
The SNLS : Overview and First results
• Introduction• Project overview• Current status and first results • Perspectives
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Introduction:The cosmological paradigm
• Today’s universe : Dark matter (30%) + Dark energy (70%)
• Dark energy: caracterised by Equation of State w=p/ w = w(z) In the following w =constant
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Introduction:The 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 <w> will give first indication of Dark energy nature
p
w
z
m
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Project: a SuperNova Legacy Survey
• PRIMARY SCIENCE GOAL : Measurement of cosmological parameters– constraint <w> 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…
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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, z=0.3-0.9 (i’ at max < 24.5 )– …
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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, z=0.3-0.9 (i’ at max < 24.5 )– …
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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, z=0.3-0.9 (i’ at max < 24.5 )– …
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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, z=0.3-0.9 (i’ at max < 24.5 )– …
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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, z=0.3-0.9 (i’ at max < 24.5 )– …
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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, z=0.3-0.9 (i’ at max < 24.5 )– …
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Means
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Means
• Team : canadian-french+others (UK+US+Port.)
– about 60 collaborators
• Telescope : CFHT+VLT+Gemini• Time :
– about 250H/year in both photometric and spectroscopic observations
• Real time detection pipelines
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Means: Telescopes & intruments
• Photometry– CFHT : 3.6 meters at Hawaii
megacam imager of 1 sq degree
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Means: Telescopes & intruments
• Spectrocopy : 8m - class– VLT + FORS1– Gemini + GMOS– Others : KECK + LRIS
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Means : Real time detection
• Principle of detection– Subtraction of each night (stacked images) on a reference
image to find individual detections
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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
- =
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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)
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 i’=24.5). 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
No human intervention is necessary up to this stage to produce the candidate list.
Detection on each stacked image
Construction and selection of the candidates
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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)
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 i’=24.5). 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
No human intervention is necessary up to this stage to produce the candidate list.
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Status: Real time lightcurves
A sample of lighcurves in each filter …
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Status: Spectroscopy
330 spectra analysed in quasi real time
190 Ia identified with template fitting Identification is performed by 2 fitting of SN database templates
(different type : Ia, Iapeculiar,Ic,IIP … and different phase) and galaxy templates.
Gemini VLT
with SN and Galaxy fitted
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Status: Survey progress
• Almost 2 years of running
May 2005
800 SN like 190 SNIa
2000 SN 700 SNIa
at the end of 2008
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Status: spectro redshift distribution
• Redshift distribution of SNIa : <z>= 0.6
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
First result: Differential photometry
• Image model=constant galaxy+point source + sky background
Fit is performed independently On each exposure
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
First Results: Lightcurve exemples
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
First results: SNLS Lightcurve fits
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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
metrics
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
First results: Hubble diagram
B = m*B – M + (s-1) –c
45 low z + 71 SNLS ( outliers removed)
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
First results: Cosmological parameter fits
• SNLS first year contours, combined with Baryon oscillation results (Eisenstein et al 2005)
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Data consistency and systematic studies
• Comparison SNLS/Nearby: stretch and color(Black) (Blue)
stretch color
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Data consistency and systematic studies
• SALT multi-band consistency U3 is the difference between measure in a third band and
expectation from SALT fit in two other band
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Data consistency and systematic studies
• Summary of error budget
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
First results: numbers
• For a flat CDM cosmology
• For a flat M,w cosmology,– Combined with Baryonic acoutic oscillation (Eisenstein 2005)
A better result than all ground-based SNe results
M=0.263 +- 0.042 (stat) +- 0.032 (syst)
M= 0.271 +- 0.021 (stat) +- 0.007 (syst)w = -1.023 +- 0.090 (stat) +- 0.054 (syst)
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Prospects :
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Prospects : error reduction
• The current status:– 71 high z SNIa :
• w> = 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
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
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
- …
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Prospects : ultimate precision
• 5 years expectations : w> = 0.07 combined with low z SNe and weak lensing of CFHTLS
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Prospects: Other science
• Other science with 2000 Sne + 1000 spectra– SN rate
– SN IIP
../..
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Prospects: Other science
Type Ia ratesMetallicity
effectsType Ia
progenitorsRedshift 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 risetimeIR Hubble Diagram
Type IIn - Type Ia connection
AGN/SN Ia connection
Ia pseudo-EW correlations
Host galaxy properties
Unique SNeIa high velocity
componentsSN 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)
SNLS:Overview and First Results, Sino-French workshop, Marseille 2005
Conclusions
• The SNLS project is entering it’s 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 !