We examine the inner mass distribution of the relaxed galaxy cluster A383 (z = 0.189), in deep 16 band Hubble Space Telescope/ACS+WFC3 imaging taken as part of the Cluster Lensing And Supernova survey with Hubble (CLASH) multi-cycle treasury program. Our program is designed to study the dark matter distribution in 25 massive clusters, and balances depth with a wide wavelength coverage, 2000-16000 angstrom, to better identify lensed systems and generate precise photometric redshifts. This photometric information together with the predictive strength of our strong-lensing analysis method identifies 13 new multiply lensed images and candidates, so that a total of 27 multiple images of nine systems are used to tightly constrain the inner mass profile gradient, d log Sigma/d log r similar or equal to -0.6 +/- 0.1 (r < 160 kpc). We find consistency with the standard distance-redshift relation for the full range spanned by the lensed images, 1.01 < z < 6.03, with the higher-redshift sources deflected through larger angles as expected. The inner mass profile derived here is consistent with the results of our independent weak-lensing analysis of wide-field Subaru images, with good agreement in the region of overlap (similar to 0.7-1 arcmin). Combining weak and strong lensing, the overall mass profile is well fitted by a Navarro-Frenk-White profile with M-vir = (5.37(-0.63)(+0.70) +/- 0.26) x 10(14) M-circle dot h(-1) and a relatively high concentration, c(vir) = 8.77(-0.42)(+0.44) +/- 0.23, which lies above the standard c-M relation similar to other well-studied clusters. The critical radius of A383 is modest by the standards of other lensing clusters, r(E) similar or equal to 16 +/- 2 '' (for z(s) = 2.55), so the relatively large number of lensed images uncovered here with precise photometric redshifts validates our imaging strategy for the CLASH survey. In total we aim to provide similarly high-quality lensing data for 25 clusters, 20 of which are X-ray-selected relaxed clusters, enabling a precise determination of the representative mass profile free from lensing bias.

Detailed studies of the stellar populations of intermediate-redshift galaxies can shed light onto the processes responsible for the significant evolution of the massive galaxy population since z < 1. We have undertaken such a study by means of deep rest-frame optical spectroscopy with IMACS on Magellan on a sample of similar to 80 galaxies selected from CDFS to have stellar masses >10(10) M-circle dot and redshift 0.65 < z < 0.75. We analyse stellar absorption line strengths and interpret them with a Monte Carlo library of star formation histories to derive constraints on mean stellar ages, metallicities and stellar masses. We present here the first characterization of the stellar mass-metallicity and stellar mass-age relations at z similar to 0.7 and their evolution to the present-day.

We utilize for the first time Hubble Space Telescope Advanced Camera for Surveys imaging to examine the structural properties of galaxies in the rest-frame U - V versus V - J diagram (i.e., the UVJ diagram) using a sample at 0.6 < z < 0.9 that reaches a low stellar mass limit (log M/M-circle dot > 10.25). The use of the UVJ diagram as a tool to distinguish quiescent galaxies from star-forming galaxies (SFGs) is becoming more common due to its ability to separate red quiescent galaxies from reddened SFGs. Quiescent galaxies occupy a small and distinct region of UVJ color space and we find most of them to have concentrated profiles with high Sersic indices (n > 2.5) and smooth structure characteristic of early-type systems. SFGs populate a broad but well-defined sequence of UVJ colors and are comprised of objects with a mix of Sersic indices. Interestingly, most UVJ-selected SFGs with high Sersic indices also display structure due to dust and star formation typical of the n < 2.5 SFGs and late-type systems. Finally, we find that the position of an SFG on the sequence of UVJ colors is determined to a large degree by the mass of the galaxy and its inclination. Systems that are closer to edge-on generally display redder colors and lower [OII]lambda 3727 luminosity per unit mass as a consequence of the reddening due to dust within the disks. We conclude that the two main features seen in UVJ color space correspond closely to the traditional morphological classes of early-and late-type galaxies.

We report the discovery of a z(phot) = 6.18(-0.07)(+0.05) (95% confidence level) dwarf galaxy, lensed into four images by the galaxy cluster MACS J0329.6-0211 (z(l) = 0.45). The galaxy is observed as a high-redshift dropout in HST/ACS/WFC3 CLASH and Spitzer/IRAC imaging. Its redshift is securely determined due to a clear detection of the Lyman break in the 18-band photometry, making this galaxy one of the highest-redshift multiply lensed objects known to date with an observed magnitude of F125W = 24.00 +/- 0.04 AB mag for its most magnified image. We also present the first strong-lensing analysis of this cluster uncovering 15 additional multiply imaged candidates of five lower-redshift sources spanning the range z(s) similar or equal to 2-4. The mass model independently supports the high photometric redshift and reveals magnifications of 11.6(-4.1)(+8.9), 17.6(-3.9)(+6.2), 3.9(-1.7)(+3.0), and 3.7(-0.2)(+1.3), respectively, for the four images of the high-redshift galaxy. By delensing the most magnified image we construct an image of the source with a physical resolution of similar to 200 pc when the universe was similar to 0.9 Gyr old, where the z similar or equal to 6.2 galaxy occupies a source-plane area of approximately 2.2 kpc(2). Modeling the observed spectral energy distribution using population synthesis models, we find a demagnified stellar mass of similar to 10(9) M-circle dot, subsolar metallicity (Z/Z(circle dot) similar to 0.5), low dust content (A(V) similar to 0.1 mag), a demagnified star formation rate (SFR) of similar to 3.2 M-circle dot yr(-1), and a specific SFR of similar to 3.4 Gyr (1), all consistent with the properties of local dwarf galaxies.

We present a strong-lensing analysis of the galaxy cluster MACS J1206.2-0847 (z = 0.44) using UV, Optical, and IR, HST/ACS/WFC3 data taken as part of the CLASH multi-cycle treasury program, with VLT/VIMOS spectroscopy for some of the multiply lensed arcs. The CLASH observations, combined with our mass model, allow us to identify 47 new multiply lensed images of 12 distant sources. These images, along with the previously known arc, span the redshift range 1 less than or similar to z less than or similar to 5.5, and thus enable us to derive a detailed mass distribution and to accurately constrain, for the first time, the inner mass profile of this cluster. We find an inner profile slope of d log Sigma/d log theta similar or equal to -0.55 +/- 0.1 (in the range [1 '', 53 ''], or 5 kpc less than or similar to r less than or similar to 300 kpc), as commonly found for relaxed and well-concentrated clusters. Using the many systems uncovered here we derive credible critical curves and Einstein radii for different source redshifts. For a source at z(s) similar or equal to 2.5, the critical curve encloses a large area with an effective Einstein radius of theta(E) = 28 '' +/- 3 '', and a projected mass of (1.34 +/- 0.15) x 10(14) M-circle dot. From the current understanding of structure formation in concordance cosmology, these values are relatively high for clusters at z similar to 0.5, so that detailed studies of the inner mass distribution of clusters such as MACS J1206.2-0847 can provide stringent tests of the Lambda CDM paradigm.

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, 20 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 (theta(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 (sigma(z) similar to 0.02(1 + z)) photometric redshifts for newly discovered arcs. Observations of each cluster are spread over eight 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).

By taking into account the local energy balance per unit volume between the viscous heating and the advective cooling plus the radiative cooling, we investigate the vertical structure of radiation pressure-supported accretion disks in spherical coordinates. Our solutions show that the photosphere of the disk is close to the polar axis and therefore the disk seems to be extremely thick. However, the density profile implies that most of the accreted matter exists in a moderate range around the equatorial plane. We show that the well-known polytropic relation between the pressure and the density is unsuitable for describing the vertical structure of radiation pressure-supported disks. More importantly, we find that the energy advection is significant even for slightly sub-Eddington accretion disks. We argue that the non-negligible advection may help us understand why the standard thin disk model is likely to be inaccurate above similar to 0.3 Eddington luminosity, which was found by some works on black hole spin measurement. Furthermore, the solutions satisfy the Solberg-Hoiland conditions, which indicate the disk to be convectively stable. In addition, we discuss the possible link between our disk model and ultraluminous X-ray sources.

We derive an accurate mass distribution of the galaxy cluster MACS J1206.2-0847 (z = 0.439) from a combined weak-lensing distortion, magnification, and strong-lensing analysis of wide-field Subaru BVR(c)I(c)z' imaging and our recent 16-band Hubble Space Telescope observations taken as part of the Cluster Lensing And Supernova survey with Hubble program. We find good agreement in the regions of overlap between several weak-and strong-lensing mass reconstructions using a wide variety of modeling methods, ensuring consistency. The Subaru data reveal the presence of a surrounding large-scale structure with the major axis running approximately northwest-southeast (NW-SE), aligned with the cluster and its brightest galaxy shapes, showing elongation with a similar to 2:1 axis ratio in the plane of the sky. Our full-lensing mass profile exhibits a shallow profile slope d ln Sigma/d ln R similar to -1 at cluster outskirts (R greater than or similar to 1 Mpc h(-1)), whereas the mass distribution excluding the NW-SE excess regions steepens farther out, well described by the Navarro-Frenk-White form. Assuming a spherical halo, we obtain a virial mass M-vir = (1.1 +/- 0.2 +/- 0.1) x 10(15) M-circle dot h(-1) and a halo concentration c(vir) = 6.9 +/- 1.0 +/- 1.2 (c(vir) similar to 5.7 when the central 50 kpc h(-1) is excluded), which falls in the range 4 less than or similar to < c > less than or similar to 7 of average c(M, z) predictions for relaxed clusters from recent. cold dark matter simulations. Our full-lensing results are found to be in agreement with X-ray mass measurements where the data overlap, and when combined with Chandra gas mass measurements, they yield a cumulative gas mass fraction of 13.7(-3.0)(+4.5)% at 0.7 Mpc h(-1) (approximate to 1.7 r(2500)), a typical value observed for high-mass clusters.

We precisely constrain the inner mass profile of A2261 (z = 0.225) for the first time and determine that this cluster is not "overconcentrated" as found previously, implying a formation time in agreement with Lambda CDM expectations. These results are based on multiple strong-lensing analyses of new 16-band Hubble Space Telescope imaging obtained as part of the Cluster Lensing and Supernova survey with Hubble. Combining this with revised weak-lensing analyses of Subaru wide-field imaging with five-band Subaru + KPNO photometry, we place tight new constraints on the halo virial mass M-vir = (2.2 +/- 0.2) x 10(15) M-circle dot h(70)(-1) (within r(vir) approximate to 3 Mpc h(70)(-1)) and concentration c(vir) = 6.2 +/- 0.3 when assuming a spherical halo. This agrees broadly with average c(M, z) predictions from recent Lambda CDM simulations, which span 5 less than or similar to < c > less than or similar to 8. Our most significant systematic uncertainty is halo elongation along the line of sight (LOS). To estimate this, we also derive a mass profile based on archival Chandra X-ray observations and find it to be similar to 35% lower than our lensing-derived profile at r(2500) similar to 600 kpc. Agreement can be achieved by a halo elongated with a similar to 2:1 axis ratio along our LOS. For this elongated halo model, we find M-vir = (1.7 +/- 0.2) x 10(15) M-circle dot h(70)(-1) and c(vir) = 4.6 +/- 0.2, placing rough lower limits on these values. The need for halo elongation can be partially obviated by non-thermal pressure support and, perhaps entirely, by systematic errors in the X-ray mass measurements. We estimate the effect of background structures based on MMT/Hectospec spectroscopic redshifts and find that these tend to lower M-vir further by similar to 7% and increase c(vir) by similar to 5%.

Hubble Space Telescope images of the galaxy cluster A2261, obtained as part of the Cluster Lensing And Supernova survey with Hubble, show that the brightest galaxy in the cluster, A2261-BCG, has the largest core yet detected in any galaxy. The cusp radius of A2261-BCG is 3.2 kpc, twice as big as the next largest core known, and similar to 3x bigger than those typically seen in the most luminous brightest cluster galaxies. The morphology of the core in A2261-BCG is also unusual, having a completely flat interior surface brightness profile, rather than the typical shallow cusp rising into the center. This implies that the galaxy has a core with constant or even centrally decreasing stellar density. Interpretation of the core as an end product of the "scouring" action of a binary supermassive black hole implies a total black hole mass similar to 10(10) M-circle dot from the extrapolation of most relationships between core structure and black hole mass. The core falls 1 sigma above the cusp radius versus galaxy luminosity relation. Its large size in real terms, and the extremely large black hole mass required to generate it, raises the possibility that the core has been enlarged by additional processes, such as the ejection of the black holes that originally generated the core. The flat central stellar density profile is consistent with this hypothesis. The core is also displaced by 0.7 kpc from the center of the surrounding envelope, consistent with a local dynamical perturbation of the core.