The Cluster Lensing And Supernova survey with Hubble (CLASH) is a 524-orbit multi-cycle treasury program to use the gravitational lensing properties of 25 galaxy clusters to accurately constrain their mass distributions. The survey, described in detail in this paper, will definitively establish the degree of concentration of dark matter in the cluster cores, a key prediction of structure formation models. The CLASH cluster sample is larger and less biased than current samples of space-based imaging studies of clusters to similar depth, as we have minimized lensing-based selection that favors systems with overly dense cores. Specifically, twenty CLASH clusters are solely X-ray selected. The X-ray selected clusters are massive (kT > 5 keV) and, in most cases, dynamically relaxed. Five additional clusters are included for their lensing strength (θ Ein > 35 at z s = 2) to optimize the likelihood of finding highly magnified high-z (z > 7) galaxies. A total of 16 broadband filters, spanning the near-UV to near-IR, are employed for each 20-orbit campaign on each cluster. These data are used to measure precise (σ z ∼ 0.02(1+z)) photometric redshifts for newly discovered arcs. Observations of each cluster are spread over 8 epochs to enable a search for Type Ia supernovae at z > 1 to improve constraints on the time dependence of the dark energy equation of state and the evolution of supernovae. We present newly re-derived X-ray luminosities, temperatures, and Fe abundances for the CLASH clusters as well as a representative source list for MACS1149.6+2223 (z = 0.544).

We have completed a 1.1 mm continuum survey of 7.5 deg 2 of the Perseus Molecular Cloud using Bolocam at the Caltech Submillimeter Observatory. This represents the largest millimeter or submillimeter continuum map of Perseus to date. Our map covers more than 30,000 31 ′′ (FWHM) resolution elements to a 1σ RMS of 15 mJy/beam. We detect a total of 122 cores above a 5σ point source mass detection limit of 0.18M ⊙ , assuming a dust temperature of T D = 10 K, 60 of which are new millimeter or submillimeter detections. The 1.1 mm mass function is consistent with a broken power law of slope α 1 = 1.3 (0.5M ⊙ < M < 2.5M ⊙ ) and α 2 = 2.6 (M > 2.5M ⊙ ), similar to the local initial mass function slopeNo more than 5% of the total cloud mass is contained in discrete 1.1 mm cores, which account for a total mass of 285M ⊙ . We suggest an extinction threshold for millimeter cores of A V ∼ 5 mag, based on our calculation of the probability of finding a 1.1 mm core as a function Recent estimates of the distance to Perseus range from 220 pc to 350 pc (e. g Černis 1990;Herbig & Jones 1983). Larger values (300 − 350 pc) are often adopted based on the

We have used the Caltech Submillimeter Observatory (CSO) to follow-up a sample of WISE-selected, hyperluminous galaxies, so called W1W2-dropout galaxies. This is a rare (∼ 1000 all-sky) population of galaxies at high redshift (peaks at z=2-3), that are faint or undetected by WISE at 3.4 and 4.6 µm, yet are clearly detected at 12 and 22 µm. The optical spectra of most of these galaxies show significant AGN activity. We observed 14 high-redshift (z > 1.7)W1W2-dropout galaxies with SHARC-II at 350 to 850 µm, with 9 detections; and observed 18 with Bolocam at 1.1 mm, with five detections. Warm Spitzer follow-up of 25 targets at 3.6 and 4.5 µm, as well as optical spectra of 12 targets are also presented in the paper. Combining WISE data with observations from warm Spitzer and CSO, we constructed their mid-IR to millimeter spectral energy distributions (SEDs). These SEDs have a consistent shape, showing significantly higher mid-IR to submm ratios than other galaxy templates, suggesting a hotter dust temperature. We estimate their dust temperatures to be 60 − 120 K using a single-temperature model. Their infrared luminosities are well over 10 13 L ⊙ . These SEDs are not well fitted with existing galaxy templates, suggesting they are a new population with very high luminosity and hot dust. They are likely among the most luminous galaxies in the Universe. We argue that they are extreme cases of luminous, hot dust-obscured galaxies (DOGs), possibly representing a short evolutionary phase during galaxy merging and evolution. A better understanding of their long-wavelength properties needs ALMA as well as Herschel data.

We present the results of a numerical study based on the analysis of the MUSIC-2 N-body/hydrodynamical simulations, aimed at estimating the expected concentration-mass relation for the CLASH cluster sample. We study nearly 1400 halos simulated at high spatial and mass resolution, which were projected along many linesof-sight each. We study the shape of both their density and surface-density profiles and fit them with a variety of radial functions, including the Navarro-Frenk-White, the generalised Navarro-Frenk-White, and the Einasto density profiles. We derive concentrations and masses from these fits and investigate their distributions as a function of redshift and halo relaxation. We use the X-ray image simulator X-MAS to produce simulated Chandra observations of the halos and we use them to identify objects resembling the X-ray morphologies and masses of the clusters in the CLASH X-ray selected sample. We also derive a concentration-mass relation for strong-lensing clusters. We find that the sample of simulated halos which resemble the X-ray morphology of the CLASH clusters is composed mainly by relaxed halos, but it also contains a significant fraction of unrelaxed systems. For such a heterogeneous sample we measure an average 2D concentration which is ∼ 11% higher than found for the full sample of simulated halos. After accounting for projection and selection effects, the average NFW concentrations of CLASH clusters are expected to be intermediate between those predicted in 3D for relaxed and super-relaxed halos. Matching the simulations to the individual CLASH clusters on the basis of the X-ray morphology, we expect that the NFW concentrations recovered from the lensing analysis of the CLASH clusters are in the range [3 − 6], with an average value of 3.87 and a standard deviation of 0.61. Simulated halos with X-ray morphologies similar to those of the CLASH clusters are affected by a modest orientation bias.

We report the discovery by the Wide-field Infrared Survey Explorer of the z = 2.452 source WISE J181417.29+341224.9, the first hyperluminous source found in the WISE survey. WISE 1814+3412 is also the prototype for an all-sky sample of ∼ 1000 extremely luminous "W1W2-dropouts" (sources faint or undetected by WISE at 3.4 and 4.6 µm and well detected at 12 or 22 µm). The WISE data and a 350 µm detection give a minimum bolometric luminosity of 3.7 × 10 13 L ⊙ , with ∼ 10 14 L ⊙ plausible. Followup images reveal four nearby sources: a QSO and two Lyman Break Galaxies (LBGs) at z = 2.45, and an M dwarf star. The brighter LBG dominates the bolometric emission. Gravitational lensing is unlikely given the source locations and their different spectra and colors. The dominant LBG spectrum indicates a star formation rate ∼ 300M ⊙ yr −1 , accounting for ∼ < 10% of the bolometric luminosity. Strong 22 µm emission relative to 350 µm implies that warm dust contributes significantly to the luminosity, while cooler dust normally associated with starbursts is constrained by an upper limit at 1.1 mm.-2 -Radio emission is ∼ 10× above the far-infrared/radio correlation, indicating an active galactic nucleus is present. An obscured AGN combined with starburst and evolved stellar components can account for the observations. If the black hole mass follows the local M BH -bulge mass relation, the implied Eddington ratio is ∼ > 4. WISE 1814+3412 may be a heavily obscured object where the peak AGN activity occurred prior to the peak era of star formation.Subject headings: galaxies: individual (WISE J181417.29+341224.9 ) WISE survey, and may be missed in surveys with substantially smaller areas by e.g., Spitzer and Herschel. Here we report on WISE J181417.29+341224.9 (hereafter WISE 1814+3412), the first hyper-luminous infrared galaxy (L IR > 10 13 L ⊙ ) discovered by WISE.Magnitudes are converted to flux densities using zeropoint values of 3631 Jy for the AB system g' and r' bands. Other magnitudes are on the Vega system, using zeropoints of 1594 and 666.7 Jy for the 2MASS system J and K s bands; 280.9 and 179.7 Jy for Spitzer IRAC [3.6] and [4.5]; and 306.7, 170.7, 29.04 & 8.284 Jy for WISE W1 through W4 respectively (Wright et al. 2010). Luminosities are calculated assuming Ω M = 0.3, Ω Λ = 0.7, and H 0 = 70 km s −1 Mpc −1 . Selection Criteria and Followup ObservationsEarly searches for the most luminous galaxies with WISE data included the investigation of outlier populations, among them objects which were only well detected in W3 and W4, including WISE 1814+3412. This approach proved highly successful (Figure 1), leading to a variety of followup programs now underway on sources which are much fainter in W1 (3.4 µm) and W2 (4.6 µm) than W3 (12 µm) or W4 (22 µm). The selection criteria for these "W1W2-dropouts" are W1 > 17.4 (< 34 µJy), and either: a) W4 < 7.7 (> 6.9 mJy) and W2 − W4 > 8.2; or b) W3 < 10.6 (> 1.7 mJy) and W2 − W3 > 5.3. W1W2-dropouts must also have at least 7 individual WISE exposures available for measurement in W3 or...