1 / 53

SNLS The Good, the Bad, and the Ugly

CFHTLS SN Survey. SNLS The Good, the Bad, and the Ugly. Chris Pritchet U. Victoria ( SNLS West ). Some history …. Riess et al. 1998 Perlmutter et al. 1998. MegaCam – 1 deg x 1 deg. “Size matters …”. Anon. MegaCam at CFHT.

dyan
Download Presentation

SNLS The Good, the Bad, and the Ugly

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

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

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

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

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

  5. MegaCam at CFHT Dark Energy Tucson 2004

  6. XMM deep VIMOS SWIRE GALEX Cosmos/ACS VIMOS SIRTF XMM … Groth strip Deep2 ACS … XMM deep CFHT Legacy Survey 470 nights (dark-grey) over 5 years (2003-2008) • SNLS - Deep (“SNe + galaxy evolution”) • 202 nights over 5 years • four 1 deg² fields (0226-04, 1000+02, 1419+53, 2215-18) • repeated observations in ugriz filters (360-950nm) • depth i’>24.5 (S/N=8, 1 hr); r’ > 28 in final stacked image • superb image quality (0.5-0.6 arcsec expected) • queue scheduling, excellent temporal sampling • ~1000 SNeIa over 5 yrs • spectroscopic followup plan (VLT, Gemini, Keck, Magellan) • Very Wide(“KBO”) • 1300 deg², +-2 deg from ecliptic, • short exposures • Wide (“lensing’) • 172 deg² in 3 patches Dark Energy Tucson 2004

  7. 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 2004

  8. Goals of SN observations – 1.Cosmology • Λ, w=P/ρ • from Type Ia SNe (exploding white dwarfs) P = wr, ρ(a) ~ a -3(1+w) w = 0 matter w = -1 L w = 1/3 radiation a(z)  w ! Linder 2002 relative to w = -0.7 model Dark Energy Tucson 2004

  9. Science goals • beat down intrinsic dispersion (±0.1–0.2 mag per SN) as N1/2 goal: ±0.01 mag error in a z bin Dark Energy Tucson 2004

  10. Expected precision on Wm, WL, w Pain 2004 1000 up to z=0.9 Flat Flat, dWm=0.03 Dark Energy Tucson 2004

  11. 2.SFR(z) – Type II SNe (core collapse) Dark Energy Tucson 2004

  12. 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

  13. The Stacks Dark Energy Tucson 2004

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

  15. 2 real time detection pipelines working well - Ca-Fr agree to i’=+24 • psfmatch2 at work diff 1999-2000 1999 2000 6hr I band 100''×100'' Dark Energy Tucson 2004

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

  17. Reliability of Faint Detections What fraction of i’=24.5 detections are real? 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

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

  19. 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

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

  21. Dark Energy Tucson 2004

  22. Spectral successes • Getting the spectroscopy time in the first place! • working scheme for coordination of telescopes • Nod & shuffle at Gemini Dark Energy Tucson 2004

  23. Nod and Shuffle – Gemini+GMOS Dark Energy Tucson 2004

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

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

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

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

  28. Spectra Statistics Dark Energy Tucson 2004

  29. z=0.84 composite (4) Dark Energy Tucson 2004

  30. Recent Light Curves Perlmutter 2004 z=0.4-0.7 Dark Energy Tucson 2004

  31. Light curves Howell, Sullivan et al 2004 0.270 0.497 0.93 z 0.695 0.87 Dark Energy Tucson 2004

  32. June 2003 i’ 1 hr (c030622-07) Sainton 2004 z=0.281 SN Iap t=-7d Dark Energy Tucson 2004

  33. R6D4-9 = c030903-1 i’max= 24.05 z=0.95 time Dark Energy Tucson 2004

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

  35. Web pages • www.cfht.hawaii.edu/CFHTLS • http://legacy.astro.utoronto.ca – photometry, spectroscopy, finder charts, light curves, calendar, … • http://makiki.cfht.hawaii.edu:872/sne/ Dark Energy Tucson 2004

  36. 6. Issues “The Dirty Dozen” Dark Energy Tucson 2004

  37. r’ i’ , less g’z’ LS vs. PI • weather • instrument failures • engineering • validation rate • seeing • focus overheads Dark Energy Tucson 2004

  38. LS Deep - i’ and z’ Dark Energy Tucson 2004

  39. 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? • 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

  40. 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 Dark Energy Tucson 2004

  41. -- Dark Energy Tucson 2004

  42. Dark Energy Tucson 2004

  43. Dark Energy Tucson 2004

  44. Dark Energy Tucson 2004

  45. Dark Energy Tucson 2004

  46. Dark Energy Tucson 2004

  47. Dark Energy Tucson 2004

  48. Telescope Aperture vs. Focal Plane Area total area in 3m+ telescopes [m2] total CCD area [Megapix] Dark Energy Tucson 2004

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

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

More Related