Development, Evaluation, And Validation Of A High-Resolution Directivity Measurement System For Played Musical Instruments,
2016
Brigham Young University - Provo
Development, Evaluation, And Validation Of A High-Resolution Directivity Measurement System For Played Musical Instruments, K Joshua Bodon
Theses and Dissertations
A high-resolution directivity measurement system at Brigham Young University has been renovated and upgraded. Acoustical treatments have been installed on the microphone array, professional-grade audio hardware and cabling have been utilized, and user-friendly MATLAB processing and plotting codes have been developed. The directivities of 16 played musical instruments and several loudspeakers have been measured by the system, processed, and plotted. Using loudspeakers as simulated musicians, a comprehensive analysis was completed to validate the system and understand its error bounds. A comparison and evaluation of repeated-capture to single-capture spherical systems was made to demonstrate the high level of detail provided by …
Improvements To The Two-Point In Situ Method For Measurement Of The Room Constant And Sound Power In Semi-Reverberant Rooms,
2016
Brigham Young University - Provo
Improvements To The Two-Point In Situ Method For Measurement Of The Room Constant And Sound Power In Semi-Reverberant Rooms, Zachary R. Jensen
Theses and Dissertations
The two-point in situ method is a technique for measuring the room constant of a semi-reverberant room and the sound power of a source in that room simultaneously using two measurement positions. Using a reference directivity source, where the directivity factor along any given axis of the source has been measured, one is able to use the Hopkins-Stryker equation to measure both the room constant and the sound power level of another source rather simply. Using both numerical and experimental data, it was found that by using generalized energy density (GED) as a measurement quantity, the results were more accurate …
The Search For Dark Matter Annihilation In Galaxy Clusters At Veritas,
2016
Purdue University
The Search For Dark Matter Annihilation In Galaxy Clusters At Veritas, James V. Tucci
Open Access Dissertations
Recent data and cosmological models point to a significant fraction of the Universe being comprised of Cold Dark Matter (DM), though little is known about it directly as it does not interact electromagnetically. The most likely explanation for DM is a Weakly Interacting Massive Particle (WIMP) having a mass as low as ∼10 GeV to as high as ∼10 TeV. WIMPs are believed to be their own antiparticles and self-annihilate into a variety of lighter particles including γ-rays. Many direct detection, indirect detection, and direct production schemes have been proposed to search for the elusive WIMP. Galaxy clusters, consisting of …
First Low Frequency All-Sky Search For Continuous Gravitational Wave Signals,
2016
The University of Texas Rio Grande Valley
First Low Frequency All-Sky Search For Continuous Gravitational Wave Signals, J. Aasi, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano
Physics & Astronomy Faculty Publications
In this paper we present the results of the first low frequency all-sky search of continuous gravitational wave signals conducted on Virgo VSR2 and VSR4 data. The search covered the full sky, a frequency range between 20 and 128 Hz with a range of spin-down between -1.0×10-10 and +1.5×10-11 Hz/s, and was based on a hierarchical approach. The starting point was a set of short fast Fourier transforms, of length 8192 s, built from the calibrated strain data. Aggressive data cleaning, in both the time and frequency domains, has been done in order to remove, as much as possible, the …
Hubble's Law Implies Benford's Law For Distances To Galaxies,
2016
Georgia Institute of Technology - Main Campus
Hubble's Law Implies Benford's Law For Distances To Galaxies, Theodore P. Hill, Ronald F. Fox
Research Scholars in Residence
A recent article by Alexopoulos and Leontsinis presented empirical evidence that the first digits of the distances from the Earth to galaxies are a reasonably good fit to the probabilities predicted by Benford’s law, the well known logarithmic statistical distribution of significant digits. The purpose of the present article is to give a theoretical explanation, based on Hubble’s law and mathematical properties of Benford’s law, why galaxy distances might be expected to follow Benford’s law. The new galaxy-distance law derived here, which is robust with respect to change of scale and base, to additive and multiplicative computational or observational errors, …
Mid-Infrared Luminous Quasars In The Goods–Herschel Fields: A Large Population Of Heavily Obscured, Compton-Thick Quasars At Z ≈ 2,
2016
Durham University, UK
Mid-Infrared Luminous Quasars In The Goods–Herschel Fields: A Large Population Of Heavily Obscured, Compton-Thick Quasars At Z ≈ 2, A. Del Moro, D. M. Alexander, F. E. Bauer, E. Daddi, Dale D. Kocevski, Daniel H. Mcintosh, F. Stanley, W. N. Brandt, D. Elbaz, C. M. Harrison, B. Luo, J. R. Mullaney, Y. Q. Xue
Physics and Astronomy Faculty Publications
We present the infrared (IR) and X-ray properties of a sample of 33 mid-IR luminous quasars (νL6 μm ≥ 6 × 1044 erg s−1) at redshift z ≈ 1–3, identified through detailed spectral energy distribution analyses of distant star-forming galaxies, using the deepest IR data from Spitzer and Herschel in the GOODS–Herschel fields. The aim is to constrain the fraction of obscured, and Compton-thick (CT, NH > 1.5 × 1024 cm−2) quasars at the peak era of nuclear and star formation activities. Despite being very bright in the mid-IR band, ≈30 …
An Hst Proper-Motion Study Of The Large Scale Jet Of 3c273,
2016
University of Maryland - Baltimore County
An Hst Proper-Motion Study Of The Large Scale Jet Of 3c273, Eileen T. Meyer, William B. Sparks, Markos Georganopoulos, Jay Anderson, Roeland Van Der Marel, John Biretta, Sangmo Tony Sohn, Marco Chiaberge, Eric S. Perlman, Colin Norman
Aerospace, Physics, and Space Science Faculty Publications
The radio galaxy 3C 273 hosts one of the nearest and best-studied powerful quasar jets. Having been imaged repeatedly by the Hubble Space Telescope (HST) over the past twenty years, it was chosen for an HST program to measure proper motions in the kiloparsec-scale resolved jets of nearby radio-loud active galaxies. The jet in 3C 273 is highly relativistic on sub-parsec scales, with apparent proper motions up to 15c observed by very long baseline interferometry. In contrast, we find that the kiloparsec-scale knots are compatible with being stationary, with a mean speed of -0.2 ±0.5c over the whole jet. Assuming …
Astrophysical Implications Of The Binary Black Hole Merger Gw150914,
2016
The University of Texas Rio Grande Valley
Astrophysical Implications Of The Binary Black Hole Merger Gw150914, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano
Physics & Astronomy Faculty Publications
The discovery of the gravitational-wave (GW) source GW150914 with the Advanced LIGO detectors provides the first observational evidence for the existence of binary black hole (BH) systems that inspiral and merge within the age of the universe. Such BH mergers have been predicted in two main types of formation models, involving isolated binaries in galactic fields or dynamical interactions in young and old dense stellar environments. The measured masses robustly demonstrate that relatively \"heavy\" BHs (≳25 M⊙) can form in nature. This discovery implies relatively weak massive-star winds and thus the formation of GW150914 in an environment with a metallicity …
A Search For Brief Optical Flashes Associated With The Seti Target Kic 8462852,
2016
Department of Physical Sciences, Cork Institute of Technology, Bishopstown, Cork, Ireland
A Search For Brief Optical Flashes Associated With The Seti Target Kic 8462852, P. T. Reynolds, Et Al
Physical Sciences Publications
The F-type star KIC 8462852 has recently been identified as an exceptional target for search for extraterrestrial intelligence (SETI) observations. We describe an analysis methodology for optical SETI, which we have used to analyze nine hours of serendipitous archival observations of KIC 8462852 made with the VERITAS gamma-ray observatory between 2009 and 2015. No evidence of pulsed optical beacons, above a pulse intensity at the Earth of approximately , is found. We also discuss the potential use of imaging atmospheric Cherenkov telescope arrays in searching for extremely short duration optical transients in general.
Search Of The Orion Spur For Continuous Gravitational Waves Using A Loosely Coherent Algorithm On Data From Ligo Interferometers,
2016
The University of Texas Rio Grande Valley
Search Of The Orion Spur For Continuous Gravitational Waves Using A Loosely Coherent Algorithm On Data From Ligo Interferometers, J. Aasi, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov
Physics & Astronomy Faculty Publications
We report results of a wideband search for periodic gravitational waves from isolated neutron stars within the Orion spur towards both the inner and outer regions of our Galaxy. As gravitational waves interact very weakly with matter, the search is unimpeded by dust and concentrations of stars. One search disk (A) is 6.87° in diameter and centered on 20h10m54.71s+33°33′25.29′′, and the other (B) is 7.45° in diameter and centered on 8h35m20.61s-46°49′25.151′′. We explored the frequency range of 50-1500 Hz and frequency derivative from 0 to -5×10-9 Hz/s. A multistage, loosely coherent search program allowed probing more deeply than before in …
Observation Of Gravitational Waves From A Binary Black Hole Merger,
2016
California Institute of Technology
Observation Of Gravitational Waves From A Binary Black Hole Merger, B. P. Abbott, K. Gill, B. Hughey, M, J. Szczepańczyk, M. Zanolin, Et Al.
Publications
On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10−21. It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater …
All-Sky Search For Long Duration Gravitational Wave Transients With Initial Ligo,
2016
Andrews University
All-Sky Search For Long Duration Gravitational Wave Transients With Initial Ligo, Tiffany Summerscales, Ligo Scientific Collaboration, Virgo Collaboration
Faculty Publications
We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10–500 s in a frequency band of 40–1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% …
All-Sky Search For Long-Duration Gravitational Wave Transients With Initial Ligo,
2016
The University of Texas Rio Grande Valley
All-Sky Search For Long-Duration Gravitational Wave Transients With Initial Ligo, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, Hernan P. Daveloza, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano
Physics & Astronomy Faculty Publications
We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% …
The Mimes Survey Of Magnetism In Massive Stars: Introduction And Overview,
2016
Swarthmore College
The Mimes Survey Of Magnetism In Massive Stars: Introduction And Overview, G. A. Wade, C. Neiner, E. Alecian, J. H. Grunhut, V. Petit, B. De Batz, D. A. Bohlender, David H. Cohen, H. F. Heinrichs, O. Kochukhov, J. D. Landstreet, N. Manset, F. Martins, S. Mathis, M. E. Oksala, S. P. Owocki, T. Rivinius, M. E. Shultz, J. O. Sundqvist, R. H. D. Townsend, A. Ud-Doula, J.-C. Bouret, J. Braithwaite, M. Briquet, A. C. Carciofi, A. David-Uraz, C. P. Folsom, A. W. Fullerton, B. Leroy, W. L. F. Marcolino, A. F. J. Moffat, Y. Nazé, N. St Louis, M. Aurière, S. Bagnulo, J. D. Bailey, R. H. Barbá, A. Blazère, T. Böhm, C. Catala, J.-F. Donati, L. Ferrario, D. Harrington, I. D. Howarth, R. Ignace, L. Kaper, T. Lüftinger, R. Prinja, J. S. Vink, W. W. Weiss, I. Yakunin
Physics & Astronomy Faculty Works
The MiMeS (Magnetism in Massive Stars) project is a large-scale, high-resolution, sensitive spectropolarimetric investigation of the magnetic properties of O- and early B-type stars. Initiated in 2008 and completed in 2013, the project was supported by three Large Program allocations, as well as various programmes initiated by independent principal investigators, and archival resources. Ultimately, over 4800 circularly polarized spectra of 560 O and B stars were collected with the instruments ESPaDOnS (Echelle SpectroPolarimetric Device for the Observation of Stars) at the Canada–France–Hawaii Telescope, Narval at the Télescope Bernard Lyot and HARPSpol at the European Southern Observatory La Silla 3.6 m …
Andrews Professor Helps Find Gravitational Waves: Ligo Research Team Makes International News,
2016
Andrews University
Andrews Professor Helps Find Gravitational Waves: Ligo Research Team Makes International News, Becky St. Clair
Andrews Agenda: Campus News
No abstract provided.
Observation Of Gravitational Waves From A Binary Black Hole Merger,
2016
The University of Texas Rio Grande Valley
Observation Of Gravitational Waves From A Binary Black Hole Merger, B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Joseph D. Romano
Physics & Astronomy Faculty Publications
On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10-21. It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater …
On R - W1 As A Diagnostic To Discover Obscured Active Galactic Nuclei In Wide-Area X-Ray Surveys,
2016
Yale University
On R - W1 As A Diagnostic To Discover Obscured Active Galactic Nuclei In Wide-Area X-Ray Surveys, Stephanie M. Lamassa, Francesca Civano, Marcella Brusa, Daniel Stern, Eilat Glikman, Sarah Gallagher, C. Meg Urry, Sabrina Cales, Nico Cappelluti, Carolin Cardamone, Andrea Comastri, Duncan Farrah, Jenny E. Greene, S. Komossa, Andrea Merloni, Tony Mroczkowski, Priyamvada Natarajan, Gordon Richards, Mara Salvato, Kevin Schawinski, Ezequiel Treister
Physics and Astronomy Publications
Capitalizing on the all-sky coverage of WISE and the 35% and 50% sky coverage from Sloan Digital Sky Survey and Pan-STARRS, respectively, we explore the efficacy of mR (optical) - (mid-infrared), hereafter , as a color diagnostic to identify obscured supermassive black hole accretion in wide-area X-ray surveys. We use the ∼16.5 deg2 Stripe 82 X-ray survey data as a test bed to compare with R - K, an oft-used obscured active galactic nucleus (AGN) selection criterion, and examine where different classes of objects lie in this parameter space. Most stars follow a well-defined path in R - K versus …
Kelt-4ab: An Inflated Hot Jupiter Transiting The Bright (V~10) Component Of A Hierarchical Triple,
2016
Swarthmore College
Kelt-4ab: An Inflated Hot Jupiter Transiting The Bright (V~10) Component Of A Hierarchical Triple, J. D. Eastman, T. G. Beatty, R. J. Siverd, J. M. O. Antognini, M. T. Penny, E. J. Gonzales, J. R. Crepp, A. W. Howard, R. L. Avril, A. Bieryla, K. Collins, B. J. Fulton, J. Ge, J. Gregorio, B. Ma, S. N. Mellon, T. E. Oberst, J. Wang, B. S. Gaudi, J. Pepper, K. G. Stassun, L. A. Buchhave, Eric L. N. Jensen, D. W. Latham, P. Berlind, M. L. Calkins, P. A. Cargile, K. D. Colón, S. Dhital, G. A. Esquerdo, J. A. Johnson, J. F. Kielkopf, M. Manner, Q. Mao, K. K. Mcleod, K. Penev, R. P. Stefanik, R. Street, R. Zambelli, D. L. Depoy, A. Gould, J. L. Marshall, R. W. Pogge, M. Trueblood, P. Trueblood
Physics & Astronomy Faculty Works
We report the discovery of KELT-4Ab, an inflated, transiting Hot Jupiter orbiting the brightest component of a hierarchical triple stellar system. The host star is an F star with ${T}_{{\rm{eff}}}$ = $6206\pm 75$ K, $\mathrm{log}g$ = $4.108\pm 0.014$, $[{\rm{Fe}}/{\rm{H}}]$ = $-{0.116}_{-0.069}^{+0.065}$, ${M}_{*}$ = ${1.201}_{-0.061}^{+0.067}$ $\;{M}_{\odot }$, and ${R}_{*}$ = ${1.603}_{-0.038}^{+0.039}$ $\;{R}_{\odot }$. The best-fit linear ephemeris is ${\mathrm{BJD}}_{\mathrm{TDB}}$ $\;=\;2456193.29157\pm 0.00021$ $\quad +\quad E(2.9895936\pm 0.0000048)$. With a magnitude of V ~ 10, a planetary radius of ${1.699}_{-0.045}^{+0.046}$ $\;{R}_{{\rm{J}}}$, and a mass of ${0.902}_{-0.059}^{+0.060}$ $\;{M}_{{\rm{J}}}$, it is the brightest host among the population of inflated Hot Jupiters (RP > 1.5RJ), making it a …
Optically Detected Magnetic Resonance Of Silicon Vacancies In Sic: Predicting Resonance Of Cylindrical Cavities,
2016
Brigham Young University
Optically Detected Magnetic Resonance Of Silicon Vacancies In Sic: Predicting Resonance Of Cylindrical Cavities, Kyle Miller, John Colton
Journal of Undergraduate Research
Optically Detected Magnetic Resonance is one method of performing Electron Spin Resonance (ESR) on a material. ESR is used to determine the electron spin lifetime of a material, an important parameter for use in quantum computing. Resonant cavities are conducting containers that are frequently used in ESR to create a strong magnetic field near the sample. As such it is valuable to design a resonant cavity and predict its resonant frequency. Cylindrical cavities modified with dielectric resonators (DRs) are viable for such experiments.
Exploring The Weak Mach Reflection Regime,
2016
Brigham Young University
Exploring The Weak Mach Reflection Regime, Kevin Leete, Dr. Kent Gee
Journal of Undergraduate Research
When a shock wave reflects off a rigid surface with certain combinations of incident shock strength and angle, a Mach reflection can occur. This is when portions of the incident and reflected waves merge to create a stronger shock called a Mach stem that travels parallel to the reflecting surface. This phenomenon has been studied extensively for two extreme cases: large outdoor explosions and small, laboratory experiments of weak shocks. The purpose of this project was to design and execute an outdoor experiment where this phenomenon could be observed by microphones as well as high speed video imaging to detect …
