Browsing FAS Scholarly Articles by Title
Now showing items 2812-2831 of 18292
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Constraining Dark Halo Potentials with Tidal Tails
(American Astronomical Society, 1999)We present an extensive parameter survey of the influence of halo mass profiles on the development of tidal tails in interacting disk galaxies. We model the galaxies using a fixed exponential disk with a central bulge and ... -
Constraining Light Colored Particles with Event Shapes
(American Physical Society, 2008)Using recently developed techniques for computing event shapes with Soft-Collinear Effective Theory, LEP event shape data is used to derive strong model-independent bounds on new colored particles. In the effective field ... -
Constraining parity violation in gravity with measurements of neutron-star moments of inertia
(American Physical Society, 2010) -
The Constraining Power of International Treaties: Theory and Methods
(Cambridge University Press, 2005)We acknowledge the contribution of von Stein (2005) in calling attention to the very real problem of selection bias in estimating treaty effects. Nonetheless, we dispute both von Stein's theoretical and empirical conclusions. ... -
Constraining primordial black-hole bombs through spectral distortions of the cosmic microwave background
(American Physical Society, 2013)We consider the imprint of super-radiant instabilities of nonevaporating primordial black holes (PBHs) on the spectrum of the cosmic microwave background (CMB). In the radiation-dominated era, PBHs are surrounded by a ... -
Constraining proposed combinations of ice history and Earth rheology using VLBI determined baseline length rates in North America
(American Geophysical Union, 1993)We predict the present-day rates of change of the lengths of 19 North American baselines due to the glacial isostatic adjustment process. Contrary to previously published research, we find that the three-dimensional motion ... -
Constraining Questions About the Organisation and Representation of Conceptual Knowledge
(Taylor & Francis (Routledge), 2003)In this article we assume a domain-specific organisation of conceptual knowledge and consider two questions: How does this architecture constrain further assumptions that might be made regarding (1) the organisation of ... -
Constraining reionization using 21-cm observations in combination with CMB and Lyα forest data
(Oxford University Press, 2010) -
Constraining Spinning Dust Parameters With the WMAP Five-Year Data
(IOP Publishing, 2009)We characterize spinning dust emission in the warm ionized medium (WIM) by comparing templates of Galactic dust and Hα with the five-year maps from the Wilkinson Microwave Anisotropy Probe (WMAP). The Hα-correlated microwave ... -
Constraining Sub-parsec Binary Supermassive Black Holes in Quasars with Multi-epoch Spectroscopy. I. The General Quasar Population
(American Astronomical Society, 2013)We perform a systematic search for sub-parsec binary supermassive black holes (BHs) in normal broad-line quasars at z < 0.8, using multi-epoch Sloan Digital Sky Survey (SDSS) spectroscopy of the broad H beta line. Our ... -
Constraining Sub-parsec Binary Supermassive Black Holes in Quasars with Multi-epoch Spectroscopy. Ii. The Population with Kinematically Offset Broad Balmer Emission Lines
(American Astronomical Society, 2014)A small fraction of quasars have long been known to show bulk velocity offsets (of a few hundred to thousands of km s(-1)) in the broad Balmer lines with respect to the systemic redshift of the host galaxy. Models to explain ... -
Constraining the Beaming of Gamma-Ray Bursts with Radio Surveys
(American Astronomical Society, 1998)The degree of beaming in gamma-ray bursts (GRBs) is currently unknown. The uncertainty in the gamma-ray-beaming angle, theta(b), leaves the total energy release (proportional to theta(b)(2)) and the event rate per galaxy ... -
Constraining the CMB optical depth through the dispersion measure of cosmological radio transients
(IOP Publishing, 2016)The dispersion measure of extragalactic radio transients, such as of recently discovered Fast Radio Burst FRB150418, can be used to measure the column density of free electrons in the intergalactic medium. The same electrons ... -
Constraining the Collisional Nature of the Dark Matter Through Observations of Gravitational Wakes
(American Astronomical Society, 2001)We propose to use gravitational wakes as a direct observational probe of the collisional nature of the dark matter. We calculate analytically the structure of a wake generated by the motion of a galaxy in the core of an ... -
Constraining the Milky Way mass with hypervelocity stars
(Elsevier BV, 2017)Context. Although a variety of techniques have been employed for determining the Milky Way dark matter halo mass distribution, the range of allowed masses spans both light and heavy values. Knowing the precise mass of our ... -
Constraining the Minimum Mass of High-redshift Galaxies and Their Contribution to the Ionization State of the Intergalactic Medium
(American Astronomical Society, 2011)We model the latest HST WFPC3/IR observations of greater than or similar to 100 galaxies at redshifts z = 7-8 in terms of a hierarchical galaxy formation model with starburst activity. Our model provides a distribution of ... -
Constraining the Nature of the Galactic Center X-Ray Source Population
(American Astronomical Society, 2005)We searched for infrared counterparts to the cluster of X-ray point sources discovered by Chandra in the Galactic center region (GCR). While the sources could be white dwarfs, neutron stars, or black holes accreting from ... -
Constraining the quasar population with the broad-line width distribution
(Oxford University Press, 2008-10-27)In this work, we test the assertion that the scatter in the mass of black holes which drive quasars should be luminosity dependent with less scatter in more luminous objects. To this end, we measure the width of the Mg II ... -
Constraining the Stellar Mass Function in the Galactic Center via Mass Loss from Stellar Collisions
(Hindawi, 2011)The dense concentration of stars and high-velocity dispersions in the Galactic center imply that stellar collisions frequently occur. Stellar collisions could therefore result in significantmass loss rates. We calculate ... -
Constraining the Structure of Sagittarius A*'s Accretion Flow with Millimeter Very Long Baseline Interferometry Closure Phases
(American Astronomical Society, 2011)Millimeter wave very long baseline interferometry (mm-VLBI) provides access to the emission region surrounding Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way, on sub-horizon scales. ...