1. The Palomar QUEST Variability Survey Charles Baltay Yale University

2. - JPL

3. Palomar-QUEST Collaboration YalePeter Andrews, Charles Baltay, Anne Bauer, Nan Ellman, Will Emmet, Nick Morgan, David Rabinowitz, Jeff Snyder, Kathy Vivas, Bob Zinn IndianaBryce Adams, Mark Gebhard, Kent Honeycutt, Jim Musser Cal TechRichard Ellis, George Djorgovski, Shri Kulkarni, Ashish Mahabal, Mike Brown, Lynn Hillenbrand, John Carpenter, Avishay Gal-Yam, Matthew Graham, Roy Williams JPLRay Bradbury, Steve Pravdo BerkeleySaul Perlmutter, Greg Aldering, Peter Nugent, Michael Woods-Vasey, et al.

4. Large Area CCD Camera for the 48” Palomar Schmidt Telescope 25.0 cm 4.6 0 19.3 cm 3.6 0 5.4 0 Diameter Clear Field of View Of the Telescope 14” Window Diameter 4 Rows of 28 CCD’s each 112 CCD’s total Each CCD – 2400 x 600 13 μ x 13 μ pixels Array 16, 800 x 9,600 pixels 161 Megapixels tot.

5. Drift Scanning Keep telescope stationary Align CCD’s with columns along line of motion of star images Synchronize clock rate to motion of star Issues to worry about: Clock rate –Precision –Variability Exposure time fixed by star image motion Resolution broadening due to curvature of star tracks on CCD –Sagitta –Clock rate variation across CCD These considerations limit CCD array size to ~ 4000 x 1000, 7.5 to 25 µ pixels Star Image

7. CCD Finger (28 CCD’s ) Return Spring Spiral CAM Base Plate Pivot Point Star Image Fig. 11 Design for the CCD rotating mechanism

8. Camera Body Shutter Filter Tray UV Blue Vis Red Up to 4 colors per Drift Scan Pass Easily Changeable Star Image

11. Data Rates in Drift Scan Mode Pixels/CCD1.44 x 10 6 CCD’s in Camera112 Total Pixels161 x 10 6 Total Bytes at 2 bytes/pixel322 x 10 6 Megabytes/139 seconds322 Data Rate2.3 Megabytes/sec Data Per Night66 Gigabytes/night In Point and Track Mode Data/Night Depends on Exposure Time Data/Night =

14. Current Observing Pattern Allocate nights about evenly between Drift Scanning and Point and Track Drift Scan Nights We do a strip 4.6 o wide (in N-S direction) by 8 hours x 15 o /hour = 120 o in RA ~ 550 square degrees/night in 4 colors “simultaneously” using one of two filter sets: Johnson UBRI, or Gunn rizz Effective exposure time ~ 140 seconds on each CCD Point and Track Nights Use single broad Red Filter on whole array, λ > 6000 Å Typically take one minute exposures, ~ 30/hour, 9.4 square degrees each Take 3 shots of the same area of sky at ~ ½ hour spacing So in a clear 8 hour night cover ~ 750 square degrees, 3 times each, one color

17. Palomar/QUEST Data – Fall 2003 Region C – RA from ~ 20 hrs to ~ 5 hrs DeclinationUBRIrizz 22½ o Nov. 6 Nov. 7 Dec. 29 18Sept. 27 Nov. 26 Oct. 2 Oct. 3 13½Aug. 31 Dec. 2 Aug. 8 Sept. 3 9Aug. 2 Sept. 5 Sept. 2 Sept. 28 4½Aug. 30 Sept. 4 Aug. 10 Sept. 29 0Sept. 1 Sept. 6 Sept. 7 Sept. 30 Oct. 1 -4½Sept. 8 Dec. 3 Oct. 4 Oct. 5 -9Oct. 6 -13½Jan. 1 -18Jan 4 -22½Jan. 5

18. Variability Time Scales Repeated observations on time scales from minutes to years: In drift scan mode, 4 repeated observations (in different colors) on the 4 rows of CCD’s spaced by ~ 4 minutes In point and track mode repeat same area of sky (in the same color) at ~ ½ hour spacing then repeat again in ~ a month In any given lunation repeat drift scan of same area of sky 4 times (2 with UBRI, 2 with rizz) at interval of a few days to weeks or a month In both point and track and in drift scan plan to cover 10,000 to 15,000 square degrees each year, repeat same area year after year for yearly variability up to ~ 5 years

20. Callibration and Limiting Magnitudes 1.Calibrate Magnitudes in each color filter using Stetson Standard Stars 2.Define Limiting Magnitude at Signal/Noise = 10/1. Estimate Lim Mag from plot of mag error vs. calib. mag for each color. 15 10 5 0 -2.2 -2.4 -2.6 -2.8 Mag Error No. of Standard Stars Calibrated Magnitude R R M (instrum) – m (Standard Star)

21. 3.Using Col 13 from Sept. 1, 2003 data, obtain ColorSeeing FWHM Sky Level e/pixel Limiting Magnitude U2.3”2019.9 B2.2”30021.7 R2.0”150020.9 I1.7”230020.2

22. Supernova Studies Four Distinct Projects: 1.Low Red Shift (Z ≤ 0.1) Type Ia’s Anchor Hubble Diagram for high Z SNe studies (Cosmology) Perlmutter, Aldering, Nugent, Woods-Vasey, Yale Group (Supernova Factory) 2.Type II (Core Collapse) Supernovae Can these be used as Standard Candles? R. Ellis, Avishay Gal-Yam, Yale Group 3.Intermediate Red Shift (0.1 ≤ Z ≤ 0.3) Type Ia’s Measure of w in Dark Energy Equation of state P = wρ Perlmutter, Aldering, Yale Group 4.Type Ib,c SNe’s S. Kulkarni, et al.

23. Expected Numbers of Supernovae  Type Ia SNE Use Rate from R. Pain, et al. (APJ 577, 120, 2002)  Type II SNE Typically 2 mags fainter than Ia’s (Hamuy & Pinto APJ 566, L63, 2002) About twice as numerous per unit volume as Ia’s (Capellaro, et al., AA 351, 459, 1999)  Estimate numbers of SNe’s for 1000 square degrees, 15 day time window Up to Z Peak mNo/1000 sq degPeak mNo/1000 sq deg 0.0517.5 219.5 6 0.1019.0 1221.0 24 0.2020.510022.5 200 0.3021.530023.5 600 0.4022.065024.01300 Type Ia SNe’s Type II SNe’s

24. Study of Type Ia Supernovae 1.Low Red Shift (Z < 0.1) Need to calibrate Hubble Diagram for high Z SNe studies; systematic studies of nearby Ia’s Rare, bright events m < 18.5 ~ 10 SNe/1000 square degrees/15 day window Palomar-QUEST is an ideal instrument for this (Supernova Factory) Need to look all year, both in drift scan and point and track *Discovery with 3 repeated QUEST scans *Photometric follow-up to get light curves McDonald lm, SMART Spectroscopic Follow-up Hawaii 2.2 m (Supernova Factory)

29. 2.Study of Type II Supernovae Question – Can Type II supernovae be used as Standard Candles? Indication by Hamuy & Pinto (ApJ 566, L63 (2002) of a correlation between SNe absolute magnitude and expansion velocity of photosphere at mid plateau

30. Palomar-QUEST plan to collect a sample of low red shift (Z < 0.1) Type II’s to establish (or otherwise) this correlation –Discovery of Type II’s on QUEST drift scan in UBRI colors *m peak < 21 *~ 20 SNe’s/1000 square degrees/15 day window –Devote one lunation per year Scan 1000 square degrees 5 times each on 2 day intervals –Use colors to separate Type II’s from Type Ia’s a la Peter Nugent –Photometric follow-up on Palomar 60” to get light curve –Spectroscopic follow-up on Palomar 200” or KECK to measure Photosphere expansion velocity (using Fe 5169 Å line?) –Measure magnitude spread after correlation correction Type Ia spread m ~ 0.17 ~

33. 3.Intermediate Red Shift (0.1 < Z < 0.4) Goal – measurement of w in p = wρ w < -1/3 Dark Energy, w = -1 Cosmological Const. Fainter, more frequent events 19 < m <22 ~ 1 SNe/square degree/15 day window Dedicated 1 month search on QUEST ~ 5 repeated scans of ~ 1000 sq. degrees get light curves near peak from QUEST Also good for search for Type II SNE’s and Bob Zinn’s RR Lyrae study Need follow-up photometry for tails of light curves (Palomar 60”?) Need spectroscopic follow-up of faint objects (m < 22!) This is a problem - …. * Suggested by Spergel & Starkman astro-ph/0204089

37. Palomar-QUEST Science Projects 1.Quasar Variability Survey (~ 15000 sq degrees) Yale Group 2.Gravitational Lensing of Quasars Yale Group 3.High Red Shift Quasars Z ≥ 6 G. Djorgovski, et al., and Yale Group 4.Type Ia Supernova Perlmutter, Aldering, Nugent, Woods-Vasey, et al., with Yale Group (Supernova Factory) 5.Type II Supernova R. Ellis, Avishay Gl-Yam and Yale Group 6.GRB’s, Tlype Ib,c Supernovae, Unusual Transients S. Kulkarni, et al., and G. Djorkovski, et at. 7.Variation of with time Yale Group with Yale Atomic Physics Group & U of Connecticut 8.Minor Planet/Kuyper Belt Object Survey Mike Brown, et al., and D. Rabinowitz, Yale 9.RR Lyrae Stars Yale (Bob Zin, Kathy Vivas, et al.) 10.Near Earth Asteroid Tracking JPL NEAT Project 11.T-Tauri Stars Lynn Hillenbrand, John Carpenter, et al. 12.Young Star Formation Kent Honeycutt, et al.