Astrophysics – Page 709 – Kavli Institute Pre-Print Publications

GALPROP WebRun: an internet-based service for calculating galactic cosmic ray propagation and associated photon emissions

Posted by klaurent August 21, 2010Stanford

Kavli Affiliate: Peter Michelson | Summary:GALPROP is a numerical code for calculating the galactic propagation of relativistic charged particles and the diffuse emissions produced during their propagation. The code incorporates as much realistic astrophysical input as possible together with latest theoretical developments and has become a de facto standard in astrophysics of cosmic rays. We […]

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Investigating reciprocity failure in 1.7-micron cut-off HgCdTe detectors

Posted by klaurent August 19, 2010Stanford

Kavli Affiliate: Tomasz Biesiadzinski | Summary:Flux dependent non-linearity (reciprocity failure) in HgCdTe NIR detectors with 1.7 micron cut-off was investigated. A dedicated test station was designed and built to measure reciprocity failure over the full dynamic range of near infrared detectors. For flux levels between 1 and 100,000 photons/sec a limiting sensitivity to reciprocity failure […]

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Velocity Structure of Self-Similar Spherically Collapsed Halos

Posted by klaurent August 11, 2010MIT

Kavli Affiliate: Edmund Bertschinger | Summary:Using a generalized self-similar secondary infall model, which accounts for tidal torques acting on the halo, we analyze the velocity profiles of halos in order to gain intuition for N-body simulation results. We analytically calculate the asymptotic behavior of the internal radial and tangential kinetic energy profiles in different radial […]

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Self-Similar Spherical Collapse with Tidal Torque

Posted by klaurent August 3, 2010MIT

Kavli Affiliate: Edmund Bertschinger | Summary:N-body simulations have revealed a wealth of information about dark matter halos however their results are largely empirical. Using analytic means, we attempt to shed light on simulation results by generalizing the self-similar secondary infall model to include tidal torque. In this first of two papers, we describe our halo […]

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Primordial gravity wave fossils and their use in testing inflation

Posted by klaurent June 21, 2010MIT

Kavli Affiliate: Kiyoshi Wesley Masui | Summary:A new effect is described by which primordial gravity waves leave a permanent signature in the large scale structure of the Universe. The effect occurs at second order in perturbation theory and is sensitive to the order in which perturbations on different scales are generated. We derive general forecasts […]

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Seen and unseen tidal caustics in the Andromeda galaxy

Posted by klaurent June 21, 2010MIT

Kavli Affiliate: Edmund Bertschinger | Summary:Indirect detection of high-energy particles from dark matter interactions is a promising avenue for learning more about dark matter, but is hampered by the frequent coincidence of high-energy astrophysical sources of such particles with putative high-density regions of dark matter. We calculate the boost factor and gamma-ray flux from dark […]

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On The Structure Of The Chan-Paton Factors For D-Branes In Type II Orientifolds

Posted by klaurent April 22, 2010Tokyo

Kavli Affiliate: Kentaro Hori | Summary:We determine the structure of the Chan-Paton factors of the open strings ending on space filling D-branes in Type II orientifolds. Through the analysis, we obtain a rule concerning possible distribution of O-plane types. The result is applied to classify the topology of D-branes in terms of Fredholm operators and […]

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Near term measurements with 21 cm intensity mapping: neutral hydrogen fraction and BAO at z

Posted by klaurent January 26, 2010MIT

Kavli Affiliate: Kiyoshi Wesley Masui | Summary:It is shown that 21 cm intensity mapping could be used in the near term to make cosmologically useful measurements. Large scale structure could be detected using existing radio telescopes, or using prototypes for dedicated redshift survey telescopes. This would provide a measure of the mean neutral hydrogen density, […]

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LSST Science Book, Version 2.0

Posted by klaurent December 1, 2009Stanford

Kavli Affiliate: Rafe Schindler | Summary:A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera […]

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Projected Constraints on Modified Gravity Cosmologies from 21 cm Intensity Mapping

Posted by klaurent November 18, 2009MIT

Kavli Affiliate: Kiyoshi Wesley Masui | Summary:We present projected constraints on modified gravity models from the observational technique known as 21 cm intensity mapping, where cosmic structure is detected without resolving individual galaxies. The resulting map is sensitive to both BAO and weak lensing, two of the most powerful cosmological probes. It is found that […]

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