1. Rencontre de Monriond 2006 SNLS 1st year cosmological results SNLS : Cosmological results from the first year dataset Dominique Fouchez, CPPM Marseille On behalf of the SNLS collaboration. Rencontres de Monriond 2006

2. Rencontre de Monriond 2006 SNLS 1st year cosmological results Plan of the talk Deep homogenous and complete SNIa observation –Detection –Photometry : deep and well sample SN lightcurves –Spectrocopy -> identification of each SN Precise Measurement –Differential photometry –Calibration Hubble diagram and cosmology –Lightcurve modelling, fitting and luminosity distance –Hubble diagram and cosmological parameter fitting –Full cosmological parameter error estimation

3. Rencontre de Monriond 2006 SNLS 1st year cosmological results Deep homogenous and complete SNIa observations –Detection –Photometry –Spectroscopy

4. Rencontre de Monriond 2006 SNLS 1st year cosmological results CFHT : 3.6 meters at Hawaii Megacam imager of 1 sq degree Observation of the 4 CFHTLS/DEEP 1d° 2 fields in 4 colors Photometry

5. Rencontre de Monriond 2006 SNLS 1st year cosmological results Detection Principle of detection : same field observed every 4 days –Subtraction of each night (stacked images) on a reference image to find individual detections then construction of Lightcurve of candidates days - =

6. Rencontre de Monriond 2006 SNLS 1st year cosmological results Photometry :deep and well sampled lightcurves Rolling search method : same field every 4 days = automatic follow up (and down!)

7. Rencontre de Monriond 2006 SNLS 1st year cosmological results Real Time Detection Need a spectroscopy a maximum of luminosity : quasi-real time detection 2 pipelines detect new candidatess in 24h hours time after observation Scanning-free-automatized detection pipeline has been set up (shapelet-neural net based detection)

8. Rencontre de Monriond 2006 SNLS 1st year cosmological results Spectroscopy Spectrocopy : 8m - class –VLT + FORS1 –Gemini + GMOS –Others : KECK + LRIS 250H/year of spectro 250H/year of photo

9. Rencontre de Monriond 2006 SNLS 1st year cosmological results March 2006 : 2.5 years of running 440 spectra analysed in quasi real time 231 Ia identified with spectroscopy, ready for cosmology The SNIa sample : Status

10. Rencontre de Monriond 2006 SNLS 1st year cosmological results Digression In addition to SNIa sample, many variable objects, which include many SN non IA. This big sample make it possible to study other science topics than cosmological parameters within the SNLS photometric+spectroscopic data They are numerous …

11. Rencontre de Monriond 2006 SNLS 1st year cosmological results Other SNLS topics Type Ia ratesMetallicity effectsType Ia progenitorsRedshift evolution Cosmology with Type II SNe SN Ia UV properties Properties of DustType 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 ratioIa metallicity cutoff Ia geometric effectsII-P risetimeIR 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, m 15 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)

12. Rencontre de Monriond 2006 SNLS 1st year cosmological results Precise Measurement of SNIa sample Differential photometry Calibration Only the first year of data has been released and will be presented in the rest of the talk –91 Sne Ia 10 miss references 6 only have 1 band 73 usable SNIa events 2 peculiars

13. Rencontre de Monriond 2006 SNLS 1st year cosmological results Differential photometry: Method Input images + variable seeing kernel (wrt best) -> Fit galaxy on a stamp Fit position (same in all images) Fit flux on each exposure

14. Rencontre de Monriond 2006 SNLS 1st year cosmological results Differential Photometry: Results Photometry close to optimal (only 15% worse than photon statistics) Lightcurve points : flux with errors (full covariance matrix)

15. Rencontre de Monriond 2006 SNLS 1st year cosmological results Photometric calibration Same Differential photometry is used to measure tertiary standard stars in each field Calibration on observed Landolt stars 1% zero point dispersion (except z)

16. Rencontre de Monriond 2006 SNLS 1st year cosmological results Hubble diagram and cosmology –Lightcurve modelling, fitting and luminosity distance –Hubble diagram and cosmological parameter fitting –Full cosmological parameter error estimation

17. Rencontre de Monriond 2006 SNLS 1st year cosmological results Lightcurve fitting with SALT method 2 parameters describe the variability of SNIa lightcurves, but the luminosity at max : s and c (stretch and color)

18. Rencontre de Monriond 2006 SNLS 1st year cosmological results Distance measurement The fitted s and c are used to correct for the brighter-slower and brighter-bluer behaviour The correction coefficients, and M have been fitted together with the cosmology on the whole lightcurve samples. The distance is then derived from magnitude at max in B restframe and s,c :

19. Rencontre de Monriond 2006 SNLS 1st year cosmological results Hubble diagram 44 low z + 71 SNLS Supernovae

20. Rencontre de Monriond 2006 SNLS 1st year cosmological results SNLS 2.5 year Hubble diagram : Coming soon...

21. Rencontre de Monriond 2006 SNLS 1st year cosmological results Cosmological parameter fits BAO: Baryonic Acoustic Oscillation Eisentein 2005

22. Rencontre de Monriond 2006 SNLS 1st year cosmological results Systematic uncertainties Possible sources : –Calibration and photometry –Evolution –Malmquist bias –Contamination –Gray dust –Lensing

23. Rencontre de Monriond 2006 SNLS 1st year cosmological results Calibration 1% on zero points :

24. Rencontre de Monriond 2006 SNLS 1st year cosmological results Evolution: Comparison Low/High Z ? No sizeable evolution ! Stretch color

25. Rencontre de Monriond 2006 SNLS 1st year cosmological results Malmquist bias ? Selection effect (keep brightest at high z) found on the data at same level as what expected from montecarlo Max of 0.05 deviation at z=1

26. Rencontre de Monriond 2006 SNLS 1st year cosmological results Summary of systematic uncertainties

27. Rencontre de Monriond 2006 SNLS 1st year cosmological results Final result Statistical error is still dominant …

28. Rencontre de Monriond 2006 SNLS 1st year cosmological results Perspectives With full the statistics 700 SNIa expected (x10 !), the measurement will start to be systematics limited Improvement on main systematics errors is under study : –Calibration : z zero point,in particular, can be improved but need other calibrators than Landolt -> join calibration campaign with CFHT to calibrate with spectrophoto standards the DEEP fields. –Detailled study of selection effects with huge Montecarlo dataset is underway. –Lightcurve modelling improvements. –…