Time Evolution Of The Reverse Shock In Sn 1006,
2011
Middlebury College
Time Evolution Of The Reverse Shock In Sn 1006, P. Frank Winkler, Andrew J. S. Hamilton, Knox S. Long, Robert A. Fesen
Dartmouth Scholarship
The Schweizer-Middleditch star, located behind the SN 1006 remnant and near its center in projection, provides the opportunity to study cold, expanding ejecta within the SN 1006 shell through UV absorption. Especially notable is an extremely sharp red edge to the Si II 1260 Å feature, which stems from the fastest moving ejecta on the far side of the SN 1006 shell—material that is just encountering the reverse shock. Comparing Hubble Space Telescope far-UV spectra obtained with the Cosmic Origins Spectrograph in 2010 and with the Space Telescope Imaging Spectrograph in 1999, we have measured the change in this feature …
The Polylogarithm And The Lambert W Functions In Thermoelectrics,
2011
Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam, Andhra Pradesh, India
The Polylogarithm And The Lambert W Functions In Thermoelectrics, Muralikrishna Molli, Kamisetty Venkataramaniah, Sree Ram Valluri
Physics and Astronomy Publications
In this work, we determine the conditions for the extremum of the figure of merit, theta2, in a degenerate semiconductor for thermoelectric (TE) applications. We study the variation of the function theta2 with respect to the reduced chemical potential mu* using relations involving polylogarithms of both integral and nonintegral orders. We present the relevant equations for the thermopower, thermal, and electrical conductivities that result in optimizing theta2 and obtaining the extremum equations. We discuss the different cases that arise for various values of r, which depends on the type of carrier scattering mechanism present in the …
Distance Scale Zero Points From Galactic Rr Lyrae Star Parallaxes,
2011
University of Texas at Austin
Distance Scale Zero Points From Galactic Rr Lyrae Star Parallaxes, G. Fritz Benedict, Barbara E. Mcarthur, Michael W. Feast, Thomas G. Barnes, Thomas E. Harrison, Jacob L. Bean, John W. Menzies, Brian Chaboyer
Dartmouth Scholarship
We present new absolute trigonometric parallaxes and proper motions for seven Population II variable stars—five RR Lyr variables: RZ Cep, XZ Cyg, SU Dra, RR Lyr, and UV Oct; and two type 2 Cepheids: VY Pyx and κ Pav. We obtained these results with astrometric data from Fine Guidance Sensors, white-light interferometers on Hubble Space Telescope. We find absolute parallaxes in milliseconds of arc: RZ Cep, 2.12 ± 0.16 mas; XZ Cyg, 1.67 ± 0.17 mas; SU Dra, 1.42 ± 0.16 mas; RR Lyr, 3.77 ± 0.13 mas; UV Oct, 1.71 ± 0.10 mas; VY Pyx, 6.44 ± 0.23 …
Thermodynamics Of Strongly Interacting Fermions In Two-Dimensional Optical Lattices,
2011
Georgetown University
Thermodynamics Of Strongly Interacting Fermions In Two-Dimensional Optical Lattices, Ehsan Khatami, Marcos Rigol
Faculty Publications
We study finite-temperature properties of strongly correlated fermions in two-dimensional optical lattices by means of numerical linked cluster expansions, a computational technique that allows one to obtain exact results in the thermodynamic limit. We focus our analysis on the strongly interacting regime, where the on-site repulsion is of the order of or greater than the band width. We compute the equation of state, double occupancy, entropy, uniform susceptibility, and spin correlations for temperatures that are similar to or below the ones achieved in current optical lattice experiments. We provide a quantitative analysis of adiabatic cooling of trapped fermions in two …
Infrared And Upconversion Spectroscopic Studies Of High Er3+Content Transparent Yag Ceramic,
2011
The University of Texas Rio Grande Valley
Infrared And Upconversion Spectroscopic Studies Of High Er3+Content Transparent Yag Ceramic, M. Pokhrel, G. A. Kumar, P. Samuel, K. I. Ueda, T. Yanagitani, H. Yagi, D. K. Sardar
Physics & Astronomy Faculty Publications
In this article, we report the detailed spectroscopic studies of high Er3+content (50%) transparent YAG ceramic co-doped with nominal Cr3+ content (0.1 mol %). Various radiative and non-radiative spectroscopic properties such as radiative decay time, fluorescence branching ratio, emission/absorption cross sections, internal radiative quantum yields of the infrared and the upconverted emission bands are explored using standard experimental and theoretical methods and compared with YAG single crystal. Results show that although the non-radiative losses are high for 50% Er doped ceramic; several radiative spectral properties are almost in agreement with those for the single crystal YAG. Furthermore, because of the …
Book Review: The Cambridge Atlas Of Herschel Objects,
2011
Florida Institute of Technology
Book Review: The Cambridge Atlas Of Herschel Objects, T. D. Oswalt
Publications
This document is Dr. Oswalt’s review of The Cambridge Atlas of Herschel Objects by James Mullaney and Wil Tirion Cambridge, 2011 183p, 0521138175 $35.00, 9780521138178 $35.00.
Thick Disks Of Edge-On Galaxies Seen Through The Spitzer Survey Of Stellar Structure In Galaxies (S4g) : Lair Of Missing Baryons?,
2011
University of Turku
Thick Disks Of Edge-On Galaxies Seen Through The Spitzer Survey Of Stellar Structure In Galaxies (S4g) : Lair Of Missing Baryons?, Sebastien Comeron, Bruce G. Elmegreen, Johan H. Knapen, Heikki Salo, Eija Laurikainen, Jarkko Laine, E. Athanassoula, Albert Bosma, Kartik Sheth, Michael W. Regan, Joannah L. Hinz, Armando Gil De Paz, Karin Menendez-Delmestre, Trisha Mizusawa, Juan Carlos Munoz-Mateos, Mark Seibert, Taehyun Kim, Debra M. Elmegreen, Dimitri A. Gadotti, Luis C. Ho, Benne W. Holwerda, Jani Lappalainen, Eva Schinnerer, Ramin Skibba
Faculty and Staff Scholarship
Most, if not all, disk galaxies have a thin (classical) disk and a thick disk. In most models thick disks are thought to be a necessary consequence of the disk formation and/or evolution of the galaxy. We present the results of a study of the thick disk properties in a sample of carefully selected edge-on galaxies with types ranging from T = 3 to T = 8. We fitted one-dimensional luminosity profiles with physically motivated functions—the solutions of two stellar and one gaseous isothermal coupled disks in equilibrium—which are likely to yield more accurate results than other functions used in …
Absolute Properties Of The Eclipsing Binary Star Hy Virginis,
2011
University of Arkansas, Fayetteville
Absolute Properties Of The Eclipsing Binary Star Hy Virginis, Claud H. Sandberg Lacy, Francis C. Fekel
Information Systems and Engineering Management Research Publications
HY Vir is found to be a double-lined F0m+F5 binary star with relatively shallow (0.3 mag) partial eclipses. Previous studies of the system are improved with 7509 differential photometric observations from the URSA WebScope and 8862 from the NFO WebScope, and 68 high-resolution spectroscopic observations from the Tennessee State University 2 m automatic spectroscopic telescope, and the 1 m coudé-feed spectrometer at Kitt Peak National Observatory. Very accurate (better than 0.5%) masses and radii are determined from analysis of the new light curves and radial velocity curves. Theoretical models match the absolute properties of the stars at an age of …
The Properties Of The Stellar Nuclei With The Host Galaxy Morphology In The Acsvcs,
2011
The University of Texas Rio Grande Valley
The Properties Of The Stellar Nuclei With The Host Galaxy Morphology In The Acsvcs, Hyun-Chul Lee
Physics & Astronomy Faculty Publications
We have revisited the ACS Virgo Cluster Survey (ACSVCS), a Hubble Space Telescope program to obtain ACS/WFC g and z bands imaging for a sample of 100 early-type galaxies in the Virgo Cluster. In this study, we examine 51 nucleated early-type galaxies in the ACSVCS in order to look into the relationship between the photometric and structural properties of stellar nuclei and their host galaxies. We morphologically dissect galaxies into five classes. We note that (1) the stellar nuclei of dwarf early-type galaxies (dS0, dE, and dE,N) are generally fainter and bluer with g > 18.95 and (g-z) < 1.40 compared to some brighter and redder counterparts of the ellipticals (E) and lenticular galaxies (S0), (2) the g-band half-light radii of stellar nuclei of all dwarf early-type galaxies (dS0, dE, and dE,N) are smaller than 20 pc and their average is about 4 pc, and (3) the colors of red stellar nuclei with (g - z) > 1.40 in bright …
A Study Of The Orbits Of The Logarithmic Potential For Galaxies,
2011
University of Western Ontario
A Study Of The Orbits Of The Logarithmic Potential For Galaxies, Sree Ram Valluri, Paul Wiegert, John Drozd, Matt Dasilva
Physics and Astronomy Publications
The logarithmic potential is of great interest and relevance in the study of the dynamics of galaxies. Some small corrections to the work of Contopoulos & Seimenis (1990) who used the method of Prendergast (1982) to find periodic orbits and bifurca- tions within such a potential are presented. The solution of the orbital radial equation for the purely radial logarithmic potential is then considered using the p-ellipse (pre- cessing ellipse) method pioneered by Struck (2006). This differential orbital equation is a special case of the generalized Burgers equation. The apsidal angle is also deter- mined, both numerically as well as …
Acceleration Of Anomalous Cosmic Rays At The Termination Shock,
2011
University of Alabama in Huntsville
Acceleration Of Anomalous Cosmic Rays At The Termination Shock, Udara Senanayake
Von Braun Symposium Student Posters
No abstract provided.
Analysis Of The Hinode Magnetograms,
2011
University of Alabama in Huntsville
Analysis Of The Hinode Magnetograms, Tae K. Kim, Marina Geneva, Julia Reich, Stefan Wolff
Von Braun Symposium Student Posters
No abstract provided.
High-Resolution Gamma-Ray Spectroscopy With Silicon Photomultipliers,
2011
University of Alabama in Huntsville
High-Resolution Gamma-Ray Spectroscopy With Silicon Photomultipliers, Emily Layden
Von Braun Symposium Student Posters
No abstract provided.
Analysis Of Solar Lyman-Alpha Backscatter Radiation In The Heliosphere,
2011
University of Alabama in Huntsville
Analysis Of Solar Lyman-Alpha Backscatter Radiation In The Heliosphere, Brian Fayock
Von Braun Symposium Student Posters
No abstract provided.
Lunar Occultation Observer: A Nuclear Astrophysics All-Sky Survey Mission Concept,
2011
University of Alabama in Huntsville
Lunar Occultation Observer: A Nuclear Astrophysics All-Sky Survey Mission Concept, Riley Freelove
Von Braun Symposium Student Posters
No abstract provided.
The Radioactive Moon,
2011
University of Alabama in Huntsville
The Radioactive Moon, Gaurish Nerurkar
Von Braun Symposium Student Posters
No abstract provided.
Fabrication And Application Of Vertically Aligned Carbon Nanotube Templated Silicon Nanomaterials,
2011
Brigham Young University - Provo
Fabrication And Application Of Vertically Aligned Carbon Nanotube Templated Silicon Nanomaterials, Jun Song
Theses and Dissertations
A process, called carbon nanotube templated microfabrication (CNT-M) makes high aspect ratio microstructures out of a wide variety of materials by growing patterned vertically aligned carbon nanotubes (VACNTs) as a framework and then infiltrating various materials into the frameworks by chemical vapor deposition (CVD). By using the CNT-M procedure, a partial Si infiltration of carbon nanotube frameworks results in porous three dimensional microscale shapes consisting of silicon-carbon nanotube composites. The addition of thin silicon shells to the vertically aligned CNTs (VACNTs) enables the fabrication of robust silicon nanostructures with edibility to design a wide range of geometries. Nanoscale dimensions are …
Hubble Space Telescope Imaging Of Post-Starburst Quasars,
2011
University of Wyoming
Hubble Space Telescope Imaging Of Post-Starburst Quasars, S. Cales, M. Brotherton, Zhaohui Shang, Vardha Bennert, Gabriela Canalizo, R. Stoll, R. Ganguly, D. Berk, Cassandra Paul, A. Diamond-Stanic
Faculty Publications
We present images of 29 post-starburst quasars (PSQs) from a Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) Wide Field Channel Snapshot program. These broadlined active galactic nuclei (AGNs) possess the spectral signatures of massive (Mburst ∼ 1010 M⊙), moderate-aged stellar populations (hundreds of Myr). Thus, their composite nature provides insight into the AGN–starburst connection. We measure quasar-to-host galaxy light contributions via semi-automated two-dimensional light profile fits of point-spread-function-subtracted images. We examine the host morphologies and model the separate bulge and disk components. The HST/ACS-F606W images reveal an equal number of spiral (13/29) and early-type (13/29) hosts, with the …
From The Big Bang To The Swaner Ecocenter: The Cosmic Biography Of Atoms,
2011
Utah State University
From The Big Bang To The Swaner Ecocenter: The Cosmic Biography Of Atoms, Shane L. Larson
Public Talks
No abstract provided.
Tidal Perturbations To The Gravitational Inspiral Of J0651+2844,
2011
The University of Texas Rio Grande Valley
Tidal Perturbations To The Gravitational Inspiral Of J0651+2844, Matthew J. Benacquista, Kelly Holley-Bockelmann
Physics & Astronomy Faculty Publications
The recently discovered J0651+2844 is a detached, eclipsing white dwarf binary with an orbital period of 765 s. We investigate the prospects for the detection of gravitational radiation from this system and estimate the effect of the tidal deformation of the low-mass component on the period evolution of the system. Because of the high inclination of the system, the amplitude of the gravitational waves at Earth will be as much as a factor of two lower than that from an optimally oriented system. The dominant contribution of tidal corrections to the period evolution comes from the increase in rotational energy …
