Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Physics (3)
- Atomic, Molecular and Optical Physics (2)
- Electrical and Computer Engineering (2)
- Engineering (2)
- Stars, Interstellar Medium and the Galaxy (2)
-
- Applied Statistics (1)
- Computer Engineering (1)
- Cosmochemistry (1)
- Earth Sciences (1)
- Electronic Devices and Semiconductor Manufacturing (1)
- External Galaxies (1)
- Geochemistry (1)
- Geology (1)
- Mineral Physics (1)
- Multivariate Analysis (1)
- Optics (1)
- Other Engineering (1)
- Statistical Methodology (1)
- Statistics and Probability (1)
- Systems and Communications (1)
- Institution
- Keyword
-
- Photometry (2)
- Star clusters (2)
- Aliasing (1)
- Amplifier (1)
- Astronomical Instrumentation (1)
-
- Atom (1)
- Atomic data (1)
- Atomic processes (1)
- BASE-9 (1)
- Bayesian software (1)
- Black hole (1)
- Bragg's Law (1)
- Conference Posters (1)
- Diffract (1)
- Doppler effect (1)
- EBIT (1)
- Electromagnetic spectrum (1)
- Electron (1)
- Electron beam ion trap (1)
- GaAs pHEMT MMIC (1)
- Gamma rays (1)
- HMXB (1)
- High mass X-ray binary (1)
- High resolution (1)
- ISM: abundances (1)
- Infrared imaging (1)
- Interference (1)
- Interferometer Michelson-Morley (1)
- Light (1)
- Low noise amplifier (1)
Articles 1 - 12 of 12
Full-Text Articles in Instrumentation
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
Ted von Hippel
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
Ted von Hippel
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 …
Phase Retrieval Using A Genetic Algorithm On The Systematic Image-Based Optical Alignment Test Bed, Jaime R. Taylor
Phase Retrieval Using A Genetic Algorithm On The Systematic Image-Based Optical Alignment Test Bed, Jaime R. Taylor
Dr. Jaime R. Taylor
NASA’s Marshall Space Flight Center’s Systematic Image-Based Optical Alignment (SIBOA) Testbed was developed to test phase retrieval algorithms and hardware techniques. Individuals working with the facility developed the idea of implementing phase retrieval by breaking the determination of the tip/tilt of each mirror apart from the piston motion (or translation) of each mirror. Presented in this report is an algorithm that determines the optimal phase correction associated only with the piston motion of the mirrors.
Multivariate Spectral Analysis Of Crism Data To Characterize The Composition Of Mawrth Vallis, Melissa Luna
Multivariate Spectral Analysis Of Crism Data To Characterize The Composition Of Mawrth Vallis, Melissa Luna
Melissa Luna
No abstract provided.
Aliasing Reduction In Staring Infrared Imagers Utilizing Subpixel Techniques, Joseph C. Gillette, Thomas M. Stadtmiller, Russell C. Hardie
Aliasing Reduction In Staring Infrared Imagers Utilizing Subpixel Techniques, Joseph C. Gillette, Thomas M. Stadtmiller, Russell C. Hardie
Russell C. Hardie
We introduce and analyze techniques for the reduction of aliased signal energy in a staring infrared imaging system. A standard staring system uses a fixed two-dimensional detector array that corresponds to a fixed spatial sampling frequency determined by the detector pitch or spacing. Aliasing will occur when sampling a scene containing spatial frequencies exceeding half the sampling frequency. This aliasing can significantly degrade the image quality. The aliasing reduction schemes presented here, referred to as microscanning, exploit subpixel shifts between time frames of an image sequence. These multiple images are used to reconstruct a single frame with reduced aliasing. If …
The Shielding Of Gravity On Earth, Vildyan Yanbikov
The Shielding Of Gravity On Earth, Vildyan Yanbikov
Vildyan Yanbikov
The shielding of gravity on Earth
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.
High Precision K-Shell Photoabsorption Cross Sections For Atomic Oxygen: Experiment And Theory, Brendan M. Mclaughlin, C P. Ballance, K P. Bowen, D J. Gardenghi, Wayne C. Stolte
High Precision K-Shell Photoabsorption Cross Sections For Atomic Oxygen: Experiment And Theory, Brendan M. Mclaughlin, C P. Ballance, K P. Bowen, D J. Gardenghi, Wayne C. Stolte
Wayne C. Stolte
Photoabsorption of atomic oxygen in the energy region below the 1s −1 threshold in X-ray spectroscopy from Chandra and XMM-Newton is observed in a variety of X-ray binary spectra. Photoabsorption cross sections determined from an R-matrix method with pseudo-states and new, high precision measurements from the Advanced Light Source (ALS) are presented. High-resolution spectroscopy with E/ΔE ≈ 4250 ± 400 was obtained for photon energies from 520 eV to 555 eV at an energy resolution of 124 ± 12 meV FWHM. K-shell photoabsorption cross section measurements were made with a re-analysis of previous experimental data on atomic oxygen at the …
Unmasking The Mysteries Of High-Mass X-Ray Binaries (Hmxbs): The Role Of The Electron Beam Ion Trap (Ebit), Carey L. Baxter, Greg Brown, Natalie Hell
Unmasking The Mysteries Of High-Mass X-Ray Binaries (Hmxbs): The Role Of The Electron Beam Ion Trap (Ebit), Carey L. Baxter, Greg Brown, Natalie Hell
Carey L Baxter
The Electron Beam Ion Trap (EBIT) uses a very narrow electron beam (~60μm) to excite and trap ions. X-ray emissions of the excited ions are then diffracted and analyzed. I studied specific spectral emission lines of ionized silicon. This data can be used as a point of reference for similar spectra measured by the satellite Chandra so that the Doppler shift due to wind around the accretion disks of High Mass X-ray Binaries (HMXBs) can be calculated. HMXBs are pairs of stars that are luminous in X-rays. They are composed of a donor star that gives up mass to an …
Lna Based On A Low Cost (~Usd1.30) Commercial Gaas Phemt Mmic Offers Wideband (0.4~1.4 Ghz) And Room-Temperature Low Noise (~0.3 Db) Performances That Satisfy The Ska Low Cost And No-Cooling Requirement, Chin-Leong Lim
Chin-Leong Lim
Introduction: New generations of radio telescopes such as the Square Kilometre Array consist of millions of receivers scattered over a continent. The array’s quantity and geographic considerations ruled out the traditional radio astronomy LNA implementation; i.e. costly InP devices cooled by high-maintenance closed-cycle helium (He) refrigerators. Several LNA designs have been proposed to address the cost and room-temperature operation constraints but none appear a clear winner. Peltier and package-scale cooling have also been proposed as a lower cost/maintenance alternative to He cooling but when multiplied by the quantity required can still carve a significant chunk of the budget. Additionally, cooling …
The Large Millimeter Telescope: Neighbors Explore The Cosmos, William M. Irvine, E Carrasco, I Aretxaga
The Large Millimeter Telescope: Neighbors Explore The Cosmos, William M. Irvine, E Carrasco, I Aretxaga
William M. Irvine
No abstract provided.