Institution
California Institute of Technology
Education•Pasadena, California, United States•
About: California Institute of Technology is a education organization based out in Pasadena, California, United States. It is known for research contribution in the topics: Galaxy & Redshift. The organization has 57649 authors who have published 146691 publications receiving 8620287 citations. The organization is also known as: Caltech & Cal Tech.
Topics: Galaxy, Redshift, Population, Star formation, Stars
Papers published on a yearly basis
Papers
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TL;DR: In this paper, a cubic field theory was constructed for all genus amplitudes of the topological A-model for all non-compact toric Calabi-Yau threefold.
Abstract: We construct a cubic field theory which provides all genus amplitudes of the topological A-model for all non-compact toric Calabi-Yau threefolds. The topology of a given Feynman diagram encodes the topology of a fixed Calabi-Yau, with Schwinger parameters playing the role of Kahler classes of the threefold. We interpret this result as an operatorial computation of the amplitudes in the B-model mirror which is the quantum Kodaira-Spencer theory. The only degree of freedom of this theory is an unconventional chiral scalar on a Riemann surface. In this setup we identify the B-branes on the mirror Riemann surface as fermions related to the chiral boson by bosonization.
911 citations
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TL;DR: The stacked aromatic heterocycles of the DNA duplex therefore serve as an efficient medium for coupling electron donors and acceptors over very long distances.
Abstract: Rapid photoinduced electron transfer is demonstrated over a distance of greater than 40 angstroms between metallointercalators that are tethered to the 5' termini of a 15-base pair DNA duplex. An oligomeric assembly was synthesized in which the donor is Ru(phen)2dppz2+ (phen, phenanthroline, and dppz, dipyridophenazine) and the acceptor is Rh(phi)2phen3+ (phi, phenanthrenequinone diimine). These metal complexes are intercalated either one or two base steps in from the helix termini. Although the ruthenium-modified oligonucleotide hybridized to an unmodified complement luminesces intensely, the ruthenium-modified oligomer hybridized to the rhodium-modified oligomer shows no detectable luminescence. Time-resolved studies point to a lower limit of 10(9) per second for the quenching rate. No quenching was observed upon metallation of two complementary octamers by Ru(phen)3(2+) and Rh(phen)3(3+) under conditions where the phen complexes do not intercalate. The stacked aromatic heterocycles of the DNA duplex therefore serve as an efficient medium for coupling electron donors and acceptors over very long distances.
910 citations
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Space Telescope Science Institute1, Spanish National Research Council2, University of the Basque Country3, Michigan State University4, Johns Hopkins University5, Tel Aviv University6, University of California, Berkeley7, California Institute of Technology8, European Southern Observatory9, Academia Sinica10, Leiden University11, University College London12, Pontifical Catholic University of Chile13, Rutgers University14, Carnegie Institution for Science15, Ohio State University16, INAF17, University of California, San Diego18, CERN19, Max Planck Society20
TL;DR: The Cluster Lensing And Supernova Survey with Hubble (CLASH) as mentioned in this paper is a 524-orbit Multi-Cycle Treasury Program to use the gravitational lensing properties of 25 galaxy clusters to accurately constrain their mass distributions.
Abstract: 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 (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 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).
910 citations
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TL;DR: In this paper, the authors investigate the physical mechanisms that shape the luminosity function of galaxies in hierarchical clustering models and demonstrate that while feedback of form 1 is able to flatten the faint end of the galaxy luminosity, this process alone does not produce the sharp cutoff observed at large luminosities.
Abstract: We investigate the physical mechanisms that shape the luminosity function of galaxies in hierarchical clustering models. Beginning with the mass function of dark matter halos in the ΛCDM (Λ cold dark matter) cosmology, we show, in incremental steps, how gas cooling, photoionization at high redshift, feedback processes, galaxy merging, and thermal conduction affect the shape of the luminosity function. We consider three processes whereby supernovae and stellar wind energy can affect the forming galaxy: (1) the reheating of cold disk gas to the halo temperature; (2) expansion of the hot, diffuse halo gas; and (3) complete expulsion of cold disk gas from the halo. We demonstrate that while feedback of form 1 is able to flatten the faint end of the galaxy luminosity function, this process alone does not produce the sharp cutoff observed at large luminosities. Feedback of form 2 is also unable to solve the problem at the bright end of the luminosity function. The relative paucity of very bright galaxies can only be explained if cooling in massive halos is strongly suppressed. This might happen if thermal conduction near the centers of halos is very efficient, or if a substantial amount of gas is expelled from halos by process 3 above. Conduction is a promising mechanism, but an uncomfortably high efficiency is required to suppress cooling to the desired level. If, instead, superwinds are responsible for the lack of bright galaxies, then the total energy budget required to obtain a good match to the galaxy luminosity function greatly exceeds the energy available from supernova explosions. The mechanism is only viable if the formation of central supermassive black holes and the associated energy generation play a crucial role in limiting the amount of stars that form in the host galaxy. The models that best reproduce the galaxy luminosity function also give reasonable approximations to the Tully-Fisher relation and the galaxy autocorrelation function.
908 citations
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TL;DR: In this article, the spectral signatures of the Landsat TM images of the Sierra Nevada were analyzed to distinguish several classes of snow from other surface covers, and a number of TM images were used for automatic analysis of alpine snow cover.
907 citations
Authors
Showing all 58155 results
Name | H-index | Papers | Citations |
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Eric S. Lander | 301 | 826 | 525976 |
Donald P. Schneider | 242 | 1622 | 263641 |
George M. Whitesides | 240 | 1739 | 269833 |
Yi Chen | 217 | 4342 | 293080 |
David Baltimore | 203 | 876 | 162955 |
Edward Witten | 202 | 602 | 204199 |
George Efstathiou | 187 | 637 | 156228 |
Michael A. Strauss | 185 | 1688 | 208506 |
Jing Wang | 184 | 4046 | 202769 |
Ruedi Aebersold | 182 | 879 | 141881 |
Douglas Scott | 178 | 1111 | 185229 |
Hyun-Chul Kim | 176 | 4076 | 183227 |
Phillip A. Sharp | 172 | 614 | 117126 |
Timothy M. Heckman | 170 | 754 | 141237 |
Zhenan Bao | 169 | 865 | 106571 |