the sn ia rate in 0.5
DESCRIPTION
The SN Ia Rate In 0.5TRANSCRIPT
The SN Ia Rate In0.5<z<0.9 ClustersThe 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
Firenze, May 2008
Gal-Yam et al. (2002)
Sharon et al. (2007)Mannucci et al. (2007)
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
Firenze, May 2008
The Cluster Sample0.5>z>0.9
x-ray luminous
Were previously observed by HST/ACS 1 epoch for free
Figure: redshift distribution
Lx distribution of MACS clusters,
Ebeling et al. (2007)
Firenze, May 2008
The Cluster Sample Cluster z
MACS0911 0.504MACS2214 0.504MACS0257 0.506MACS0018 0.540 (aka CL0016) MACS1149 0.544MACS1423 0.545MACS0717 0.548 MACS0454 0.550 (aka MS0451) MACS2129 0.570MACS0647 0.584SDSS1004 0.680MACS0744 0.686MS1054 0.830CL0152 0.831CL1226 0.888
Firenze, May 2008
HST imaging
Epoch 1: Archival, ≥1 orbit in I814 or i775(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)
Firenze, May 2008
Search
Promptly after observation
Image subtraction
All by human (i.e., me )
Total search area:340 arcmin2
37 candidates
Firenze, May 2008
Hosts Redshifts
Keck Sprctroscopy w/ LRIS or DEIMOS
1’’ Longslit / multislit mask
Firenze, May 2008
Spectra examples
Firenze, May 2008
Hosts Redshifts
Keck Sprctroscopy w/ LRIS or DEIMOS1’’ Longslit / multislit mask
9* hosts @cluster z (*one via sdss photo-z)2 hostless8 BG8 FG3 AGN7 ???
8-16 cluster events (?)
Firenze, May 2008
SN Candidates – examples1. cluster events
z=0.55
z=0.54
z=0.89 z=0.83
z=0.55
z=0.83
4.4’’
Firenze, May 2008
SN Candidates – examples2. 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’’
Firenze, May 2008
SN Candidates – examples3. hostless
Cluster z=0.504
Cluster z=0.570
Firenze, May 2008
Numbers to rates:
iibandiLt
SNeRateSN
,
#
Sum over all images Control time
Cluster stellar-luminosity enclosed in search area
*
Firenze, May 2008
Stellar Luminosity
Subaru photometry in BVRIz’ (Ebeling et al.)
0.5x0.5 deg centered on cluster
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)
Firenze, May 2008
Stellar Luminosity
Subaru photometry in BVRIz’ (Ebeling et al.)
0.5x0.5 deg centered on clusterStar / galaxy separation
Net flux inside search area = total flux in area – sky flux density x area ‘cluster SED’
Firenze, May 2008
Stellar Luminosity
(E Spec. Template: Kinney et al. 1996)
Firenze, May 2008
Stellar Luminosity
(Spec. Template: Kinney et al. 1996)
Firenze, May 2008
Stellar Luminosity
(Spec. Template: Kinney et al. 1996)
Firenze, May 2008
Stellar Luminosity
(Spec. Template: Kinney et al. 1996)
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 x1012 LB
Firenze, May 2008
Numbers to rates:
iibandiLt
SNeRateSN
,
#
Sum over all images Control time
Cluster stellar-luminosity enclosed in search area
*
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
Firenze, May 2008
Search Efficiency Simulations
Firenze, May 2008
Search Efficiency Simulations
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)
Firenze, May 2008
Results
Gal-Yam et al. (2002)
Sharon et al. (2007)Mannucci et al. (2008)
SNuB ~ 0.5 SNe/(100yr 1010 LB)
SNuM ~ 0.12 SNe/(100yr 1010 M)
PRELIMINARY