Dark Energy Tucson 2004 SNLS The Good, the Bad, and the Ugly Chris Pritchet SNLS West U. Victoria (SNLS West) CFHTLS SN Survey

Dark Energy Tucson 2004 Some history … Riess et al Perlmutter et al. 1998

Dark Energy Tucson 2004 “Size matters …” Anon. MegaCam – 1 deg x 1 deg

Dark Energy Tucson 2004 MegaCam at CFHT  40 x (2048 x 4612) chips (~ 400Megapixels)  good blue response

Dark Energy Tucson 2004 MegaCam at CFHT

Dark Energy Tucson 2004 CFHT Legacy Survey 470 nights (dark-grey) over 5 years ( )  SNLS - Deep (“SNe + galaxy evolution”)  202 nights over 5 years  four 1 deg² fields ( , , , ) XMM deep VIMOS SWIRE GALEX Cosmos/ACS VIMOS SIRTF XMM … Groth strip Deep2 ACS … XMM deep  repeated observations in ugriz filters ( nm)  depth i’>24.5 (S/N=8, 1 hr); r’ > 28 in final stacked image  superb image quality ( arcsec expected)  queue scheduling, excellent temporal sampling  ~1000 SNeIa over 5 yrs  spectroscopic followup plan (VLT, Gemini, Keck, Magellan)  Wide (“lensing’)  172 deg² in 3 patches  Very Wide (“KBO”)  1300 deg², +-2 deg from ecliptic,  short exposures

Dark Energy Tucson 2004 Collaborative status  MOU with France – full collaboration project led by C/F communities goal is C ~ F in contribution Collaborative Board (Pain is chair for 2 yr)  MOU’s with UK and US completed

Dark Energy Tucson 2004 The Team(s) France: R. Pain (CB Chair), P. Astier, J. Rich … Canada - U. Toronto: R. Carlberg, A. Howell, T. Merrall, K. Perrett, M. Sullivan Canada - U. Victoria: C. Pritchet (SN Coordinator), D. Balam, D. Neill (Aug 2004) US: S. Perlmutter + … UK: I. Hook + …

Dark Energy Tucson Cosmology Goals of SN observations – 1. Cosmology  Λ, w=P/ρ  from Type Ia SNe (exploding white dwarfs) P = w  ρ (a) ~ a -3(1+w) w = 0 matter w = -1  w = 1/3 radiation a(z)  w ! Linder 2002 relative to w = -0.7 model

Dark Energy Tucson m telescopes (z and type) SN type peak mag stretch factor k-corrections i/s absorption Issues

Dark Energy Tucson 2004

Science goals  beat down intrinsic dispersion (±0.1–0.2 mag per SN) as N 1/2 goal: ±0.01 mag error in a z bin

Dark Energy Tucson 2004 Expected precision on  m,  , w Flat Flat,  m = up to z=0.9 Pain 2004

Dark Energy Tucson 2004 SFR(z) – Type II SNe (core collapse) 2. SFR(z) – Type II SNe (core collapse) Ia Ia II II progenitor 1 or 2 white dwarfs massive star mechanism mass transfer or merger core collapse progenitor age ~10 10 yr~10 7 yr evolution with z little(1+z) 2-4 :

Dark Energy Tucson 2004  Other applications  SNeII cosmology: v(exp) gives intrinsic luminosity  galaxy evolution, correlation functions (deep stacked images)  variable AGN’s  other variable objects  SN properties vs galaxy properties  rates Sullivan et al 2002 Perlmutter et al 1998

Dark Energy Tucson 2004 The Stacks

Dark Energy Tucson 2004 Comparison with other projects  Essence  Essence …  ~200 SNe to 2006  VRI, 900s, lower z  larger area [8 deg²]  Oct-Dec only  4+ day samples

Dark Energy Tucson 2004 SNAP w(t)=w o +w 1 t+…

Dark Energy Tucson 2004 SNLS - Current Status  First SN discovered Mar 2003  Survey underway officially since Aug 2003 Mar 2003 Feb 2003 diff

Dark Energy Tucson 2004  2 real time detection pipelines working well - Ca-Fr agree to i’=+24  psfmatch2 at work diff hr I band 100''×100''

Dark Energy Tucson 2004 Detections  143 in 03B (candidates)  80-90% overlap Ca-Fr to i’=24

Dark Energy Tucson 2004 Reliability of Faint Detections What fraction of i’=24.5 detections are real? Answer:45 objects i’>24.5: Answer: of 45 objects i’>24.5: 2 psfmatch errors 2 other/unknown others (89%) showed real light variations (though not necessarily SNe)

Dark Energy Tucson 2004 Detections vs radius [deg] R [deg]

Dark Energy Tucson 2004 i’ detections vs. seeing Complex! (# of new detections) ~ (# nights elapsed since last detections) Normalize # by dt before comparing with seeing  median ~0.4 SNe/night/field

Dark Energy Tucson 2004 Is it a SNeIa? z? ESO – 240 hr over 2 yr committed Gemini – 120 hr/yr (Can/UK/US) Keck – 40 hr/yr Perlmutter Magellan - ??? hr/yr (UofT + Freedman et al) Other (Ellis on Keck, DEEP2 on Keck)  Spectroscopic followup for ~ SNeIa/yr

Dark Energy Tucson 2004 Spectral successes  working scheme for coordination of telescopes  Getting the spectroscopy time in the first place!

Dark Energy Tucson 2004

Spectral successes  working scheme for coordination of telescopes  Nod & shuffle at Gemini  Getting the spectroscopy time in the first place!

Dark Energy Tucson 2004 Nod and Shuffle – Gemini+GMOS

Dark Energy Tucson 2004 Spectral successes  Toronto program for predicting type/phase  working scheme for coordination of telescopes  Nod & shuffle at Gemini  Getting the spectroscopy time in the first place!

Dark Energy Tucson 2004 Spec-z / Photo-z Slight over-estimate in photo-z, indicating that photometry is systematically faint But this should be improved once we switch to Elixir Uses only two epochs of SNaproc photometry! Sullivan, Howell et al SNIa SNII AGNSpec confirmed

Dark Energy Tucson 2004 Pre-screening candidates – AGN AGN what comes out of fitting code without knowing the true z blue = AGN red = Ia green = II

Dark Energy Tucson 2004 Pre-screening candidates – SN/AGN? SN/AGN? purple = AGN red = Ia green = II (from spec)

Dark Energy Tucson 2004 Pre-screening candidates – SN? SN? purple = AGN red = Ia green = II

Dark Energy Tucson 2004 Spectra Statistics

Dark Energy Tucson 2004 z=0.84 composite (4)

Dark Energy Tucson 2004 Recent Light Curves Perlmutter 2004 z=

Dark Energy Tucson 2004 Light curves Howell, Sullivan et al z

Dark Energy Tucson 2004 June 2003 i’ 1 hr (c ) z=0.281 SN Iap t=-7d Sainton 2004

Dark Energy Tucson 2004 R6D4-9 = c time i’ max = z=0.95

Dark Energy Tucson 2004 Rudimentary Hubble diagram  Absolute calibration unknown  Relative filter-to-filter calibration not yet confirmed  Bias to brighter objects at higher-redshift  Preliminary photometry Howell, Sullivan et al 2004 = wrong z, not Ia EdS ΛCDM

Dark Energy Tucson 2004 Web pages   – photometry, spectroscopy, finder charts, light curves, calendar, …legacy.astro.utoronto.ca 

Dark Energy Tucson Issues “The Dirty Dozen”

Dark Energy Tucson 2004 LS vs. PI ProgramAllocatedValidated % validated Deep L01+L hr91 hr66% Wide L02+L hr40 hr36% Very-Wide L03+L06 71 hr21 hr30% Total LS 318 hr 152 hr 48% PI 375 hr 185 hr 49% weather instrument failures engineering validation rate seeing focus overheads r’ i’, less g’z’

Dark Energy Tucson 2004  LS Deep - i’ and z’

Dark Energy Tucson Scheduling Issues – 2. Scheduling Issues – QSO has worked well, but …  how to handle demands of other surveys in bad weather? how to get more g’z’ in bad weather? 3.Image Quality - 3.Image Quality - corrector problems 4. Calibration how achievable is 0.01 mag precision? zeropoints – esp.in colour (matching k-corr’s at different redshifts) uniformity across array variation in colour terms (esp u* and z’) CFHT preprocessing pipeline (“Elixir”) “phase closure”

Dark Energy Tucson 2004 Conclusions  “The Ugly”: less data than hoped for in 2003B less g’z’  “The Bad”: IQ – natural seeing and corrector calibration/photometry issues to solve  “The Good”: team detection pipelines spectroscopy “ugly” and “bad” mostly understood and preventable in 2004A“ugly” and “bad” mostly understood and preventable in 2004A

Dark Energy Tucson

Dark Energy Tucson 2004

Telescope Aperture vs. Focal Plane Area total CCD area [Megapix] total area in 3m+ telescopes [m 2 ]

Dark Energy Tucson 2004

Light-curve coverage at low redshift encompasses up to 15 epochs French and Canadian photometry not yet completely consistent, should be improved once we switch to Elixir. Howell, Sullivan et al 2004 “Real” fits

Dark Energy Tucson 2004 “Real” fits Moving up in redshift Coverage is still good Howell, Sullivan et al 2004

Dark Energy Tucson 2004 “Real” fits Intermediate redshift Howell, Sullivan et al 2004

Dark Energy Tucson 2004 “Real” fits …and higher redshift… Howell, Sullivan et al 2004

Dark Energy Tucson 2004 “Real” fits And “high” redshift. Photometry is much nosier. Peak in i is about 24.2 Howell, Sullivan et al 2004

Dark Energy Tucson 2004 Features of CFHTLS SNe Survey  imaging area (4 x 1 deg²) 2 x 1 deg² fields available at any time  4-5 colours - (u*)g’r’i’z’  superb image quality ( arcsec expected)  depth (1hr in i’, 24.5 at S/N>8)  queue scheduling excellent temporal sampling  ~1000 SNeIa over 5 yrs  spectroscopic followup plan (ESO VLT, Keck, Gemini N+S, Magellan) allocated