1. The SN Ia Rate In 0.5<z<0.9 Clusters Keren Sharon Tel Aviv University Keren Sharon Tel Aviv University Avishay Gal-Yam, Dani Maoz, Alex Filippenko, Ryan Foley, Jeff Silverman, Harald Ebeling, C.J. Ma, Eran Ofek, Megan Donahue, Richard Ellis,Robert Kirshner, Thomas Matheson, John Mulchaey, Vicki Sarajedini, Mark Voit

2. Firenze, May 2008 Gal-Yam et al. (2002) Sharon et al. (2007) Mannucci et al. (2007)

3. Firenze, May 2008 Overview 15 Clusters at 0.5< z <0.9 HST imaging (PI Gal-Yam) Follow-up & luminosity from ground (@Keck, Palomar, Subaru) Found ~10 cluster candidates

4. Firenze, May 2008 The Cluster Sample 0.5>z>0.9 x-ray luminous Were previously observed by HST/ACS  1 epoch for free Figure: redshift distribution L x distribution of MACS clusters, Ebeling et al. (2007)

5. Firenze, May 2008 The Cluster Sample Cluster z MACS09110.504 MACS22140.504 MACS0257 0.506 MACS0018 0.540 (aka CL0016) MACS1149 0.544 MACS1423 0.545 MACS0717 0.548 MACS0454 0.550 (aka MS0451) MACS2129 0.570 MACS0647 0.584 SDSS1004 0.680 MACS0744 0.686 MS1054 0.830 CL0152 0.831 CL1226 0.888

6. Firenze, May 2008 HST imaging Epoch 1: Archival, ≥1 orbit in I 814 or i 775 (and additional bands for some clusters) Epoch 2: cycle 14, 1 orbit/cluster (4x~500s) Epoch 3: cycle 15, 1 orbit/cluster (but 6 clusters not observed due to ACS’ untimely death)

7. Firenze, May 2008 Search Promptly after observation Image subtraction All by human (i.e., me ) Total search area: 340 arcmin 2  37 candidates

8. Firenze, May 2008 Hosts Redshifts Keck Sprctroscopy w/ LRIS or DEIMOS 1’’ Longslit / multislit mask

9. Firenze, May 2008 Spectra examples

10. Firenze, May 2008 Hosts Redshifts Keck Sprctroscopy w/ LRIS or DEIMOS 1’’ Longslit / multislit mask  9* hosts @cluster z (*one via sdss photo-z) 2 hostless 8 BG 8 FG 3 AGN 7 ??? 8-16 cluster events (?)

11. Firenze, May 2008 SN Candidates – examples 1. cluster events z=0.55 z=0.54 z=0.89z=0.83 z=0.55 z=0.83 4.4’’

12. Firenze, May 2008 SN Candidates – examples 2. field events z=0.87(bg) z=0.49(fg) z=0.23(fg)z=0.62(bg) z=0.75(bg) z=0.58(bg) 4.4’’

13. Firenze, May 2008 SN Candidates – examples 3. hostless Cluster z=0.504 Cluster z=0.570

14. Firenze, May 2008 Numbers to rates: Sum over all images Control time Cluster stellar- luminosity enclosed in search area **

15. Firenze, May 2008 Stellar Luminosity Subaru photometry in BVRIz’ (Ebeling et al.) 0.5x0.5 deg centered on cluster

16. Firenze, May 2008 Stellar Luminosity Subaru photometry in BVRIz’ (Ebeling et al.) 0.5x0.5 deg centered on cluster Star / galaxy separation light profile / half-light radius scales with magnitude  stars and other point sources populate a well-defined locus in this plot, and can be separated from galaxies. ● MU_MAX = peak surface brightness above the background level. (SExtractor)

17. Firenze, May 2008 Stellar Luminosity Subaru photometry in BVRIz’ (Ebeling et al.) 0.5x0.5 deg centered on cluster Star / galaxy separation Net flux inside search area = total flux in area – sky flux density x area  ‘cluster SED’

18. Firenze, May 2008 Stellar Luminosity (E Spec. Template: Kinney et al. 1996)

19. Firenze, May 2008 Stellar Luminosity (Spec. Template: Kinney et al. 1996)

20. Firenze, May 2008 Stellar Luminosity (Spec. Template: Kinney et al. 1996)

21. Firenze, May 2008 Stellar Luminosity (Spec. Template: Kinney et al. 1996)

22. Firenze, May 2008 Stellar Luminosity Convert VRIz’ to restframe B / g Correct for faint end of luminosity function, due to magnitude limit (usually m~25) Results: enclosed B-band stellar luminosity, typically ~ 2-5 x10 12 L  B

23. Firenze, May 2008 Numbers to rates: Sum over all images Control time Cluster stellar- luminosity enclosed in search area ** 

24. Firenze, May 2008 Search Efficiency Simulations >120 Fake SNe were blindly added to each image Reduction and search as in real data Recovery rate noted as function of magnitude

25. Firenze, May 2008 Search Efficiency Simulations

26. Firenze, May 2008 Search Efficiency Simulations

27. Firenze, May 2008 Uncertainties Statistical: Poisson errors of order 30% Systematic: rate estimated many times by Monte-Carlo simulation, drawing: Stretch factor from Sullivan et al. (2006) Luminosity, efficiency from their distributions (e.g., see Sharon et al. 2007) Classification uncertainty (in progress)

28. Firenze, May 2008 Results Gal-Yam et al. (2002) Sharon et al. (2007) Mannucci et al. (2008) SNu B ~ 0.5 SNe/(100yr 10 10 L  B ) SNuM ~ 0.12 SNe/(100yr 1010 M  ) PRELIMINARY