CLASH: C luster L ensing A nd S upernova survey with H ubble. M. Postman, P.I., with 34 co-investigators (18 institutions, 10 countries) . WFC3 Parallels. Cluster Pointings. ACS Parallels. 6 arcmin. = 2.2 Mpc @ z=0.5. SN search cadence: 10d-20d , 4 epochs per orient.
M. Postman, P.I., with 34 co-investigators (18 institutions, 10 countries)
6 arcmin. = 2.2 Mpc @ z=0.5
SN search cadence:
10d-20d, 4 epochs per orient
Footprints of HST Cameras: ACS FOV in yellow,
WFC3/IR FOV in red, WFC3/UVIS in blue.
Lensing amplification small at these radii
524 orbits, 25 clusters, 16 filters, ~3 years
Abell 383 core
All clusters have
Tx > 5 keV
z_med ~ 0.4
Cutouts of x-ray images of 23 of the 25 CLASH clusters from Chandra Observatory
Why 16 filters?
Mag distn of multiply lensed arcs in A1689 and CL0024
Arcs in A1689 and CL0024
Will yield photometric redshifts with rms error of
~2% x(1 + z) for sources down to ~26 AB mag.
What is the characteristic distribution of DM in a typical cluster, and what implications does this distribution have for structure formation and the nature of DM?
Umetsu et al. 2010
LCDM prediction from Duffy et al. 2008
Abell 1689 Coe et al. 2010
HST Image of Cluster Reconstructed Mass Surface Density
Region of Reliable Reconstruction
DM substructure resolution in this map is ~23 kpc. DM substructure resolution for typical CLASH cluster will be ~30 – 40 kpc.
Abell 383 SN Candidate “Caligula” cluster cores?
Abell 383 SN Candidate “Nero”Does the Equation of State of Dark Energy Depend on Time?
Reference Discovery Difference
Nov 18, 2010 Dec 8, 2010 Dec 28, 2010
ACS, F850LP, z ~ 0.3
WFC3-IR, F160W, z ~ 0.7 or 1.7
Expect CLASH to find 10 – 20 SNe at z>1; and ~6 with z > 1.5, doubling the known number of z > 1 SNe.
Two MCT HST programs (CLASH and CANDELS) will detect SNe Ia at 1.0 < z < 2.5.
CLASH and CANDELS provide a direct test of the SN systematics in a matter-dominated universe.
Δ mag (vs. wo = -1, wa = 0)
Bradley et al. 2010 (in prep): Abell 1703 – Brightest z ~ 7 candidate known (H160 ~ 24.3 AB), μ ~ 3 - 5
Zitrin et al. 2010
z = 4.92 Galaxy
How object would look without cluster lensing
Lensing greatly enhances the ability to detect distant galaxies and provides an additional constraint on their redshifts, as the projected position of the lensed object is a function of the source redshift.
Strongly Lensing Clusters with 3 or more filters from HST (ACS and/or WFC3)
Figure credit: Dan Coe
CLASH doubles the number of SL clusters with >3 HST passbands.
CLASH has uniform and well-defined sample selection criteria.
Vast improvement in number of SLCswith >6 passbands – new territory for science.