Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Cosmology, Relativity, and Gravity (5)
- Physics (5)
- Stars, Interstellar Medium and the Galaxy (4)
- Optics (3)
- Physical Processes (2)
-
- Aerospace Engineering (1)
- Applied Statistics (1)
- Atmospheric Sciences (1)
- Atomic, Molecular and Optical Physics (1)
- Business (1)
- Condensed Matter Physics (1)
- Earth Sciences (1)
- Engineering (1)
- Engineering Physics (1)
- Environmental Indicators and Impact Assessment (1)
- Environmental Monitoring (1)
- Environmental Sciences (1)
- Medical Specialties (1)
- Medicine and Health Sciences (1)
- Oceanography and Atmospheric Sciences and Meteorology (1)
- Oncology (1)
- Other Earth Sciences (1)
- Other Environmental Sciences (1)
- Quantum Physics (1)
- Statistics and Probability (1)
- Systems Engineering and Multidisciplinary Design Optimization (1)
- Technology and Innovation (1)
- Institution
- Keyword
-
- Photometry (3)
- Astronomy (2)
- Star clusters (2)
- Atomic physics (1)
- BASE-9 (1)
-
- Bayesian software (1)
- Bose-Einstein Condensate (1)
- Camera (1)
- Conference Posters (1)
- DSLR (1)
- Digital (1)
- Dosimetry (1)
- Environmental testing (1)
- Eye plaque brachytherapy (1)
- FAPARchl (1)
- Field programmable gate arrays (1)
- GPP (1)
- Gravitational waves (1)
- Gravitational waves--Mathematical models--Case studies (1)
- I-125 (1)
- Interfereometry (1)
- Interferometer Michelson-Morley (1)
- LISA (1)
- Laser cooling (1)
- Low frequency all sky monitor (1)
- Low frequency all sky monitor correlator (1)
- MOD15A2 FPAR (1)
- MODIS (1)
- Mass ratios (1)
- Monte Carlo cluster simulator (1)
- Publication
- Publication Type
Articles 1 - 15 of 15
Full-Text Articles in Instrumentation
Should We Love Or Hate Big Data? The Good, The Bad, And The Ugly, Dennis Crossen M.Sc., Mba, Karti Puranam Phd, Madjid Tavana Phd
Should We Love Or Hate Big Data? The Good, The Bad, And The Ugly, Dennis Crossen M.Sc., Mba, Karti Puranam Phd, Madjid Tavana Phd
Explorer Café
No abstract provided.
The Power Of Principled Bayesian Methods In The Study Of Stellar Evolution, Ted Von Hippel, David Van Dyk, David Stenning, Elliot Robinson, Elizabeth Jeffery, Nathan Stein, William Jefferys, Erin M. O'Malley
The Power Of Principled Bayesian Methods In The Study Of Stellar Evolution, Ted Von Hippel, David Van Dyk, David Stenning, Elliot Robinson, Elizabeth Jeffery, Nathan Stein, William Jefferys, Erin M. O'Malley
Publications
It takes years of effort employing the best telescopes and in- struments to obtain high-quality stellar photometry, astrometry, and spectroscopy. Stellar evolution models contain the experience of life- times of theoretical calculations and testing. Yet most astronomers fit these valuable models to these precious datasets by eye. We show that a principled Bayesian approach to fitting models to stellar data yields substantially more information over a range of stellar astrophysics. We highlight advances in determining the ages of star clusters, mass ratios of binary stars, limitations in the accuracy of stellar models, post-main-sequence mass loss, and the ages of individual …
Bayesian Analysis For Stellar Evolution With Nine Parameters (Base-9): User's Manual, Ted Von Hippel, Elliot Robinson, Elizabeth Jeffery, Rachel Wagner-Kaiser, Steven Degennaro, Nathan Stein, David Stenning, William H. Jefferys, David Van Dyk
Bayesian Analysis For Stellar Evolution With Nine Parameters (Base-9): User's Manual, Ted Von Hippel, Elliot Robinson, Elizabeth Jeffery, Rachel Wagner-Kaiser, Steven Degennaro, Nathan Stein, David Stenning, William H. Jefferys, David Van Dyk
Publications
BASE-9 is a Bayesian software suite that recovers star cluster and stellar parameters from photometry. BASE-9 is useful for analyzing single-age, single-metallicity star clusters, binaries, or single stars, and for simulating such systems. BASE-9 uses Markov chain Monte Carlo and brute-force numerical integration techniques to estimate the posterior probability distributions for the age, metallicity, helium abundance, distance modulus, and line-of-sight absorption for a cluster, and the mass, binary mass ratio, and cluster membership probability for every stellar object. BASE-9 is provided as open source code on a version-controlled web server. The executables are also available as Amazon Elastic Compute Cloud …
The Optical Luminosity Function Of Gamma-Ray Bursts Deduced From Rotse-Iii Observations, X. H. Cui, X. F. Wu, J. J. Wei, F. Yuan, W. K. Zheng, E. W. Liang, C. W. Akerlof, M. C. B. Ashley, H A. Flewelling, E. Göǧüş, T. Güver, Ü. Kızıloǧlu, T. A. Mckay, S. B. Pandey, E. S. Rykoff, W. Rujopakarn, B. E. Schaefer, J. C. Wheeler, Sarah A. Yost
The Optical Luminosity Function Of Gamma-Ray Bursts Deduced From Rotse-Iii Observations, X. H. Cui, X. F. Wu, J. J. Wei, F. Yuan, W. K. Zheng, E. W. Liang, C. W. Akerlof, M. C. B. Ashley, H A. Flewelling, E. Göǧüş, T. Güver, Ü. Kızıloǧlu, T. A. Mckay, S. B. Pandey, E. S. Rykoff, W. Rujopakarn, B. E. Schaefer, J. C. Wheeler, Sarah A. Yost
Physics Faculty Publications
We present the optical luminosity function (LF) of gamma-ray bursts (GRBs) estimated from a uniform sample of 58 GRBs from observations with the Robotic Optical Transient Search Experiment III (ROTSE-III). Our GRB sample is divided into two sub-samples: detected afterglows (18 GRBs) and those with upper limits (40 GRBs). We derive R-band fluxes for these two sub-samples 100 s after the onset of the burst. The optical LFs at 100 s are fitted by assuming that the co-moving GRB rate traces the star formation rate. While fitting the optical LFs using Monte Carlo simulations, we take into account the …
Can We Use The Nasa Gamma-Ray Burst Satellites, Fermi And Swift, To Aid The Search For The First Gravitational Wave Detection?, E Burns
Von Braun Symposium Student Posters
No abstract provided.
Digital Optical Correlator X-Ray Telescope Alignment Tracking System, Tomasz Marek Lis
Digital Optical Correlator X-Ray Telescope Alignment Tracking System, Tomasz Marek Lis
Von Braun Symposium Student Posters
No abstract provided.
Laser Frequency Stabilization For Lisa, Andrew B. Parker, Andrew J. Sutton, Glenn De Vine
Laser Frequency Stabilization For Lisa, Andrew B. Parker, Andrew J. Sutton, Glenn De Vine
STAR Program Research Presentations
This research focuses on laser ranging developments for LISA (Laser Interferometer Space Antenna), a planned NASA-ESA gravitational wave detector in space. LISA will utilize precision laser interferometry to track the changes in separation between three satellites orbiting 5 million kilometers apart. Specifically, our goal is to investigate options for laser frequency stabilization. Previous research has shown that an optical cavity system can meet LISA's stability requirements, but these units are large and heavy, adding cost to the implementation. A heterodyne Mach-Zehnder interferometer could be integrated onto LISA’s existing optical bench, greatly reducing the weight, provided the interferometer meets the stability …
Environmental Testing Of Lasers For Jpl's Cold Atom Laboratory, Carey L. Baxter
Environmental Testing Of Lasers For Jpl's Cold Atom Laboratory, Carey L. Baxter
STAR Program Research Presentations
NASA’s Cold Atom Lab (CAL) is a multi-user facility designed to study ultra-cold quantum gases in the microgravity environment of the International Space Station (ISS). One of the main goals of CAL is to explore the unknown territory of extremely low temperatures—possibly as low as the picokelvin range!—where new and fascinating quantum phenomena can be observed. At such temperatures matter stops behaving as particles and instead becomes macroscopic matter waves. CAL will be remotely controlled to perform a multitude of experiments and is scheduled to launch in 2016. In order to anticipate problems that might occur during and post-launch, including …
Maximizing Precision Of Variable Star Photometry With Digital Cameras In Suburban Environments, David Hergesheimer
Maximizing Precision Of Variable Star Photometry With Digital Cameras In Suburban Environments, David Hergesheimer
STAR Program Research Presentations
Photometry is the measure of the brightness of an object. When making such measurements on stars, it is done is units of magnitude, which is on a logarithmic scale with a base of ~2.512. Variable star photometry using a commercially available digital camera is not going to be as accurate and precise as equipment used by astronomers, and because of the logarithmic scale of magnitude used, determining how much of an effect different error reduction strategies have is not straightforward, and is best done experimentally.
My research is conducting photometry on variable stars (changing brightness) with a digital camera, and …
Globular Cluster Simulations By Mocca Code, Dongming Jin
Globular Cluster Simulations By Mocca Code, Dongming Jin
Theses and Dissertations - UTB/UTPA
The MOCCA code is one of the most advanced codes that has the capacity to simulate a realistic sized star cluster with a full dynamical history including stellar evolution using Monte Carlo methods for the cluster evolution and the Fewbody code for scattering. The dynamical evolution of a cluster can result in the formation of many binary systems. Some of these binaries may be very close. Close double white dwarf binaries (double WDBs) may be promising gravitational wave sources. Our work uses MOCCA to simulate 90 globular clusters with different numbers of stars, binary fractions, metallicities and power-law indices of …
A Digital Backend For The Low Frequency All Sky Monitor, Louis Percy Dartez
A Digital Backend For The Low Frequency All Sky Monitor, Louis Percy Dartez
Theses and Dissertations - UTB/UTPA
The Low Frequency All Sky Monitor (LoFASM) is a distributed array of dipole antennas that are sensitive to radio frequencies from 10 to 88 MHz. The primary science goals of LoFASM are the detection and study of low-frequency radio transients, a high priority science goal as deemed by the National Research Council's decadal survey. LoFASM consists of antennas and front-end electronics that were originally developed for the Long Wavelength Array (LWA) by the U.S. Naval Research Lab, the University of New Mexico, Virginia Tech, and the Jet Propulsion Laboratory. LoFASM, funded by the U.S. Department of Defense, will initially consist …
Estimation Of Crop Gross Primary Production (Gpp): FaparChl Versus Mod15a2 Fpar, Qingyuan Zhang, Yen-Ben Cheng, A. I. Lyapustin, Yujie Wang, Feng Gao, Andrew E. Suyker, Shashi B. Verma, Elizabeth M. Middleton
Estimation Of Crop Gross Primary Production (Gpp): FaparChl Versus Mod15a2 Fpar, Qingyuan Zhang, Yen-Ben Cheng, A. I. Lyapustin, Yujie Wang, Feng Gao, Andrew E. Suyker, Shashi B. Verma, Elizabeth M. Middleton
School of Natural Resources: Faculty Publications
Photosynthesis (PSN) is a pigment level process in which antenna pigments (predominately chlorophylls) in chloroplasts absorb photosynthetically active radiation (PAR) for the photochemical process. PAR absorbed by foliar non-photosynthetic components is not used for PSN. The fraction of PAR absorbed (fAPAR) by a canopy/vegetation (i.e., fAPARcanopy) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) images, referred to as MOD15A2 FPAR, has been used to compute absorbed PAR (APAR) for PSN (APARPSN) which is utilized to produce the standard MODIS gross primary production (GPP) product, referred to as MOD17A2 GPP. In this study, the fraction of PAR …
Quantitative Characteristics Of A Rotating Interferometer Michelson-Morley Experiment, Vildyan Yanbikov
Quantitative Characteristics Of A Rotating Interferometer Michelson-Morley Experiment, Vildyan Yanbikov
Vildyan Yanbikov
Calculation of quantitative characteristics of rotating interferometer Michelson-Morley experiment. The objective of the experiment. Confirmation alternate the Lorentz contraction of the interferometer arms as it rotates.
Characterizing And Quanifying Time Dependent Night Sky Brightness In And Around Tucson, Arizona, Rachel K. Nydegger
Characterizing And Quanifying Time Dependent Night Sky Brightness In And Around Tucson, Arizona, Rachel K. Nydegger
Rachel Nydegger Rozum
No abstract provided.
Reevaluation Of The Aapm Tg-43 Brachytherapy Dosimetry Parameters For An 125I Seed, And The Influence Of Eye Plaque Design On Dose Distributions And Dose-Volume Histograms, Prakash Aryal
Theses and Dissertations--Physics and Astronomy
The TG-43 dosimetry parameters of the AdvantageTM 125I model IAI-125A brachytherapy seed were studied. An investigation using modern MCNP radiation transport code with updated cross-section libraries was performed. Twelve different simulation conditions were studied for a single seed by varying the coating thickness, mass density, photon energy spectrum and cross-section library. The dose rate was found to be 6.3% lower at 1 cm in comparison to published results. New TG-43 dosimetry parameters are proposed.
The dose distribution for a brachytherapy eye plaque, model EP917, was investigated, including the effects of collimation from high-Z slots. Dose distributions for …