SDSS Supernova Survey Josh Frieman Fermilab and University of Chicago

Jan. 12, 2005 AAS2 SDSS and SDSS II SDSS I: April 2000-June 2005 SDSS II: July (contingent on funding): Legacy Survey (complete northern survey) ~10 6 redshifts SEGUE (low-latitude survey of Milky Way) see posters 64.09, , Supernova Survey see poster by H. Lampeitl and by S. Krughoff

Jan. 12, 2005 AAS3 Fermilab: Jen Adelman-McCarthy, Fritz DeJongh, Juan Estrada, Hubert Lampeitl, John Marriner, Chris Stoughton, Doug Tucker U. Chicago: Ben Dilday, Rick Kessler, Erin Sheldon, Don York, Gary Kilper, Mark Subbarao U. Washington: Andy Becker, Gajus Miknaitis, Craig Hogan Portsmouth: Bob Nichol, Bruce Bassett NMSU/APO: Jon Holtzman, Bill Ketzeback, Jack Dembicky, Russet McMillan, John Barentine, Scot Kleinman, Howard Brewington, Mike Harvanek, Atsuko Nitta, Stephanie Snedden, Dan Long, Jerzy Krzesinski, Peter Newman Princeton: Dave Johnston, Jim Gunn U. Pittsburgh: Andy Connolly, Simon Krughoff, Ryan Scranton JPG: Mamoru Doi, Naoki Yasuda, Naohiro Takanashi Stanford: Roger Romani, Masao Sako, Jared Kaplan, Roger Blandford, Steve Kahn Ohio State: Darren Depoy, Jennifer Marshall STScI: Adam Riess LBNL: Lifan Wang U. Texas: Peter Hoeflich SF State: Dennis Lamenti SDSS SN Collaborators

DateSDSS Supernovae4 a(t) Expansion History of the Universe

Jan. 12, 2005 AAS5 Type Ia Supernovae & Cosmology Advantages: small dispersion in peak brightness (standard candles) single objects (simpler than galaxies) can be observed over wide redshift range (bright) Challenges/Systematic concerns: dust extinction in host galaxy chemical composition variations/evolution evolution of progenitor population photometric calibration Malmquist bias environmental differences K correction uncertainties Need new SN surveys for statistics and systematics

Jan. 12, 2005 AAS6 Tonry etal ‘03 0.3, , , 0.0 Brightness relative to empty Universe: (  m =   =0)  m   Compiled Supernovae Ia Sample `Gold’ sample of ~150 SNe included only 5 between z = ; SDSS naturally fills this gap

Jan. 12, 2005 AAS7 The SDSS SN Program Repeat ugriz imaging of ~2.5 o x100 o deg. region along celestial equator for three 3-month runs (Sept-Nov. ‘05-’07): 310<RA<50 Frame subtraction in SDSS gri SN Ia selection in 24 hrs Follow-up spectroscopy for SN typing, redshift (other telescopes) Multi-epoch spectrophotometry for improved K-corrections Follow-up NIR imaging for host extinction & properties Obtain ~200 high-quality, densely sampled SN Ia light-curves in the redshift desert z = 0.05 – 0.35 (exposure time 55 sec on 2.5m telescope; limits g~r~22.2 in `good’ seeing) 5-band photometry, large survey volume also allow selection of unusual type II, Ibc, etc., for further study Rapid release of candidates and data

Jan. 12, 2005 AAS8 Science Goals Probe Dark Energy in z regime less sensitive to evolution than deeper surveys Study SN Ia systematics (critical for SN cosmology) with high photometric accuracy Search for additional parameters to reduce Ia dispersion Determine SN/SF rates/properties vs. z, environment Rest-frame u-band templates for z >1 surveys Study feasibility of cosmology with SN colors Database of Type II and other SN light-curves

Jan. 12, 2005 AAS9 Monte Carlo Data Distance modulus Simulated redshift distribution and photometric errors for completed SDSS SN sample (here assumed   =0.7=1–  m H 0 =72)

Jan. 12, 2005 AAS10 Fall 2004: Early Science & Test Run Imaging: 20 nights of SDSS 2.5m scheduled every other night late Sept.-mid Nov., covered half the survey area: ~1/2 the nights were useable. Follow-up spectroscopy: ARC 3.5m, HET 9.2m Follow-up imaging (during/after run): NMSU 1m, ARC 3.5m Science Goal: ~10 well-measured SN Ia light-curves with confirmed spectroscopic types and redshifts. Yield: 16 confirmed Ia’s: 0.05<z<0.32 with  z  = 0.15, 5 Type II, 1 luminous Type Ic Engineering goals met: Rapid processing and selection of candidates in g,r (48 hours) Coordinated follow-up observations Study detection efficiency and photometric accuracy under varying conditions

Jan. 12, 2005 AAS11 SN Ia z= epochs of spectroscopy

Jan. 12, 2005 AAS12 Preliminary u+0.25 g r–0.75 i–2 z– Magnitude

Jan. 12, 2005 AAS13 SN 83: Observed vs. Synthetic Light-curves (preliminary)

Jan. 12, 2005 AAS14 Highest redshift Ia from this sample: z=0.32 Luminous Ia: M r ~ –20 Cross-correlation analysis yields best-fit Ia spectral templates separated by 2 days, in excellent agreement with data

Jan. 12, 2005 AAS15 Type II Type Ic

Jan. 12, 2005 AAS16 SDSS II SN Follow-up Spectroscopy: SN typing, redshift, multi-epoch spectrophotometry NIR imaging: extinction/reddening and lightcurves Spectroscopy: ARC 3.5m, HET, MDM 2.4m (new high-throughput spectrograph), Subaru, SALT?, Gemini? NIR imaging: Liverpool Telescope, Carnegie Supernova Project, Calar Alto Optical imaging: NMSU 1m, ARC 3.5m, …

Jan. 12, 2005 AAS17 Conclusions SDSS SN Survey: SDSS 2.5m, ~200 SNe, z = , Sept-Nov , fill in the redshift desert Successful early science and test run Fall 2004: results out soon In combination with WMAP CMB data, the SDSS SN survey should determine the Dark Energy equation of state parameter w to ~10-15% statistical accuracy (assuming w constant) and provide new insight into SN Ia systematics. Combining SDSS SN data with that of deeper on-going surveys (ESSENCE, CFHTLS, z= ) should lead to improved cosmological constraints, due to broader redshift leverage.