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Articles 1 - 30 of 74
Full-Text Articles in Physics
An Introduction To The Veritas Observatory, Alexander Biddle, Ian Kuhl, Jingze (Justin) Zhou, Avery Archer
An Introduction To The Veritas Observatory, Alexander Biddle, Ian Kuhl, Jingze (Justin) Zhou, Avery Archer
Annual Student Research Poster Session
Located at the base of Mount Hopkins, Arizona, at an elevation of approximately 4200 feet, the Very Energetic Radiation Imaging Telescope Array System (VERITAS) is a ground-based gamma ray observatory containing four Cherenkov telescopes designed to detect very high energy gamma rays with energies ranging from 100GeV to 10TeV using the Imaging Atmospheric Cherenkov Technique. In April 2007, VERITAS began successful operations with all four telescopes. As of today, over 15 years of data has been taken by the VERITAS array, stored in an archive of data, and used for a wide variety of research, publications, PhD theses, and conventions …
Analysis Of The Crab Nebula And Pulsar, Alexander Biddle, Ian Kuhl, Jingze (Justin) Zhou, Avery Archer
Analysis Of The Crab Nebula And Pulsar, Alexander Biddle, Ian Kuhl, Jingze (Justin) Zhou, Avery Archer
Annual Student Research Poster Session
Although the Crab Nebula is well understood, the Very Energetic Radiation Imaging Telescope Array System (VERITAS) still regularly observes the Crab's highest energy emissions. These emissions are used to calibrate the telescopes, further, document the system, and investigate the validity of physical models. Our research this summer is geared to analyze data from 2018-2022 to add to an ongoing research project investigating the long term variability of the Crab Nebula’s emission.
Sub-Chandrasekhar Type Ia Supernovae Scenarios With Increased Pathways For Neutronization, Fernando Hernan Rivas
Sub-Chandrasekhar Type Ia Supernovae Scenarios With Increased Pathways For Neutronization, Fernando Hernan Rivas
Doctoral Dissertations
Type Ia supernovae are thermonuclear explosions of white dwarfs (WD), electron-degenerate cores of old intermediate mass stars(under 8$M_{\odot}$). Reaching energies of $10^{51}$\si{\erg}, they outshine whole galaxies as they synthesize and distribute most of the iron group elements (IGE; V, Cr, Mn, Fe, Co, Ni) into the interstellar medium, thus being one of the main agents in cosmic chemical evolution. Also, given their notably homogeneous lightcurves, they form the last step in the cosmic distance ladder outdistancing Cepheid variables by orders of magnitude. Though calibration of said lightcurves is dependent on a high number of confirmed events, the limits of statistical …
The Search For Heavily Obscured Active Galactic Nuclei In The Local Universe, Ross Silver
The Search For Heavily Obscured Active Galactic Nuclei In The Local Universe, Ross Silver
All Dissertations
Active galactic nuclei (AGN) are supermassive black holes (SMBHs) in the center of galaxies that accrete surrounding gas and emit across the entire electromagnetic spectrum. They are the most energetic persistent emitters in the Universe, capable of outshining their host galaxies despite their emission originating from a region smaller than our Solar System. AGN were some of the first sources discovered that helped teach us that there were galaxies outside of our own, and they proved the existence of black holes. Moreover, AGN can give us valuable insights into other branches of astrophysics. For example, they can be used to …
Exploring The Dependence Of Bulges In Spiral Galaxies On Their Environment, William Jackson Clark
Exploring The Dependence Of Bulges In Spiral Galaxies On Their Environment, William Jackson Clark
Physics Theses & Dissertations
Recent research has shown a relationship between spiral galaxy satellite populations and the size of spiral bulges. The modern cosmological model of our universe (ΛCDM), does not predict this. Instead, ΛCMD predicts that only the total dynamical mass of a host galaxy should be correlated with satellite populations. We investigate this relationship in regimes other than satellites. In this study we compare the bulge to total mass ratios of spiral galaxies to the number of nearby galaxies within “n” Mpc. We use four papers from literature that calculate bulge to total mass ratios of 189 spiral galaxies using …
Cross Sections Of The 83rb (P,Γ)84sr And 84kr(P,Γ)85rb Reactions At Energies Characteristic Of The Astrophysical Γ Process, M. Williams, B. Davids, G. Lotay, N. Nishimura, T. Rauscher, S. A. Gillespie, M. Alcorta, Alan M. Amthor, G. C. Ball, S. S. Bhattacharjee, V. Bildstein, W. N. Catford, D. T. Doherty, N. E. Esker, A. B. Garnsworthy, G. Hackman, K. Hudson, A. Lennarz, C. Natzke, B. Olaizola, A. Psaltis, C. E. Svensson, J. Williams, D. Walter, D. Yates
Cross Sections Of The 83rb (P,Γ)84sr And 84kr(P,Γ)85rb Reactions At Energies Characteristic Of The Astrophysical Γ Process, M. Williams, B. Davids, G. Lotay, N. Nishimura, T. Rauscher, S. A. Gillespie, M. Alcorta, Alan M. Amthor, G. C. Ball, S. S. Bhattacharjee, V. Bildstein, W. N. Catford, D. T. Doherty, N. E. Esker, A. B. Garnsworthy, G. Hackman, K. Hudson, A. Lennarz, C. Natzke, B. Olaizola, A. Psaltis, C. E. Svensson, J. Williams, D. Walter, D. Yates
Faculty Journal Articles
We have measured the cross section of the 83 Rb ( p , γ ) 84 Sr radiative capture reaction in inverse kinematics using a radioactive beam of 83 Rb at incident energies of 2.4 and 2.7 A MeV. Prior to the radioactive beam measurement, the 84 Kr ( p , γ ) 85 Rb radiative capture reaction was measured in inverse kinematics using a stable beam of 84 Kr at an incident energy of 2.7 A MeV. The effective relative kinetic energies of these measurements lie within the relevant energy window for the γ process in supernovae. The central …
Measurement Of Near-Threshold Proton Branching Ratios In 31s Important For Novae, Sudarsan Balakrishnan
Measurement Of Near-Threshold Proton Branching Ratios In 31s Important For Novae, Sudarsan Balakrishnan
LSU Doctoral Dissertations
Classical novae are stellar explosions that contribute to the nucleosynthesis of isotopes on the proton-rich side of the valley of stability up to 40Ca. In ONe novae, the incompletely understood reaction rate of 30P(p,γ)31S is known to strongly influence the production rate of several stable isotopes such as 30Si, 31P, and 32,33,34S. A precise measurement of this reaction rate has several potential implications towards matching astrophysical observables to the physical composition of the nova site -- the observed elemental abundance ratios of O/S and S/Al have been suggested as useful `thermometers' to gauge …
Electromagnetic Radiation From A Spherical Static Current Source Coupled To Harmonic Axion Field, Railing Chang, Huai-Yi Xie, P. T. Leung
Electromagnetic Radiation From A Spherical Static Current Source Coupled To Harmonic Axion Field, Railing Chang, Huai-Yi Xie, P. T. Leung
Physics Faculty Publications and Presentations
The electromagnetic fields generated from a static current source on a spherical surface are calculated in the framework of axion electrodynamics to first order in the coupling parameter. Comparisons of the results are made with reference to various results obtained in conventional Maxwell electrodynamics, as well as previous results obtained for point magnetic dipole source coupled to harmonic axion fields. Distinct features from the results so obtained are highlighted for possible experimental probing of the axions via electromagnetic interactions. In particular, electromagnetic radiation from sources with strong magnetic field is studied which may enable the detection of a cosmic …
Dirac Dark Matter, Neutrino Masses, And Dark Baryogenesis, Diego Restrepo, Andrès Rivera, Walter Tangarife
Dirac Dark Matter, Neutrino Masses, And Dark Baryogenesis, Diego Restrepo, Andrès Rivera, Walter Tangarife
Physics: Faculty Publications and Other Works
We present a gauged baryon number model as an example of models where all new fermions required to cancel out the anomalies help to solve phenomenological problems of the standard model (SM). Dark fermion doublets, along with the isosinglet charged fermions, in conjunction with a set of SM-singlet fermions, participate in the generation of small neutrino masses through the Dirac-dark Zee mechanism. The other SM-singlets explain the dark matter in the Universe, while their coupling to an inert singlet scalar is the source of the CP violation. In the presence of a strong first-order electroweak phase transition, this “dark” CP …
Deep Space And The Quantum Mechanical Case: A Study Of Stars To The First Bsu Direct Measurement Of A Singular Photon, Darius Desnoes
Deep Space And The Quantum Mechanical Case: A Study Of Stars To The First Bsu Direct Measurement Of A Singular Photon, Darius Desnoes
Honors Program Theses and Projects
While it is known that physics can be split into several different fields, it may be foreign to see how different fields of physics operate hand in hand with one another to solve complex problems. For instance, Maxwell’s equations involving E&M for the propagation of electro-magnetic waves can be used to understand light-based interferometry for astrophysics, which directly led to the creation of intensity-based interferometry. Eventually, the measurements and equations made by intensity-based interferometry would produce groundbreaking strides in quantum mechanics through the direct measurement of singular particles. An in-depth analysis of each of these connections and how they involved …
Signal Yields And Detector Modeling In Xenon Time Projection Chambers, And Results Of An Effective Field Theory Dark Matter Search Using Lux Data, Gregory Ransford Carl Rischbieter
Signal Yields And Detector Modeling In Xenon Time Projection Chambers, And Results Of An Effective Field Theory Dark Matter Search Using Lux Data, Gregory Ransford Carl Rischbieter
Legacy Theses & Dissertations (2009 - 2024)
The nature of dark matter continues to be one of the biggest remaining mysteries in physics. Astrophysical measurements indicate that dark matter makes up more than a quarter of the Universe's total energy density, and it is well-motivated that dark matter is comprised of Weakly Interacting Massive Particles (WIMPs). Direct detection techniques utilizing liquid and gaseous noble elements have become the primary method of probing the potential non-gravitational interactions between WIMPs and Standard Model matter, with the leading technology being the dual-phase Time Projection Chamber (TPC). The Large Underground Xenon (LUX) and its second-generation successor, LUX-ZEPLIN (LZ), are two xenon …
Physical Properties Of Brackett Emitters In The Apogee Dr17 Catalog, Elliott Khilfeh, Hunter Campbell, Kevin R. Covey, Marina Kounkel, Richard Ballentyne
Physical Properties Of Brackett Emitters In The Apogee Dr17 Catalog, Elliott Khilfeh, Hunter Campbell, Kevin R. Covey, Marina Kounkel, Richard Ballentyne
WWU Honors College Senior Projects
In the process of accumulating mass (accretion), young stars channel ionized gas from the protoplanetary disk to the stellar surface along magnetic field lines. Upon impacting the photosphere, the gas cools down, recombining and emitting hydrogen spectral lines. Measuring these emission lines allows us to determine the temperature and density of the gas in those accretion streams. This then enables us to test whether those parameters depend on the accretion rate. We present measurements of equivalent widths and line ratios for Brackett (Br) 11 – 20 lines for 3366 observations of 940 pre-main sequence stars observed with APOGEE as of …
Characterizing Agn Influence On The Calculated Metallicities Of Adjacent Star-Forming Spaxels, Aidan Khelil
Characterizing Agn Influence On The Calculated Metallicities Of Adjacent Star-Forming Spaxels, Aidan Khelil
Honors Papers
In this thesis, I introduce a method to identify and characterize the effects of active galactic nuclei (AGN) on the spectra of nearby star-forming regions. I analyze spatially-resolved areas of galaxies called “spaxels” within Data Release 15 of the Sloan Digital Sky Survey (SDSS) with the goal of locating those which are physically close to AGN. I find those spaxels with calculated metallicities which lie adjacent to AGN-flagged spaxels and characterize their metallicity values relative to the spaxels which are not adjacent to AGN-flagged spaxels, using a total of 11 separate metallicity calibrations. I find that the current methods to …
Nnetfix: An Artificial Neural Network-Based Denoising Engine For Gravitational-Wave Signals, Kentaro Mogushi, Ryan Quitzow-James, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Nnetfix: An Artificial Neural Network-Based Denoising Engine For Gravitational-Wave Signals, Kentaro Mogushi, Ryan Quitzow-James, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
Instrumental and environmental transient noise bursts in gravitational-wave (GW) detectors, or glitches, may impair astrophysical observations by adversely affecting the sky localization and the parameter estimation of GW signals. Denoising of detector data is especially relevant during low-latency operations because electromagnetic follow-up of candidate detections requires accurate, rapid sky localization and inference of astrophysical sources. NNETFIX is a machine learning, artificial neural network-based algorithm designed to estimate the data containing a transient GW signal with an overlapping glitch as though the glitch was absent. The sky localization calculated from the denoised data may be significantly more accurate than the sky …
Accretion And Debris Disc Dynamics Around Single And Higher-Order Star Systems, Jeremy L. Smallwood
Accretion And Debris Disc Dynamics Around Single And Higher-Order Star Systems, Jeremy L. Smallwood
UNLV Theses, Dissertations, Professional Papers, and Capstones
My research deals with highly topical areas of astrophysics, such as planet habitability, stellar evolution, the origin of fast radio bursts, the evolution of debris discs, and the dynamics of accretion discs in binary and higher-order star systems. Accretion discs around binary star systems are ubiquitous in the galaxy and planet formation is thought to occur within these discs. Circumbinary discs are commonly observed to be misaligned with respect to the binary orbital plane. A misaligned circumbinary disc eventually evolve to a stable orientation, either coplanar or polar with the binary orbital plane. The process of disc alignment has important …
All-Sky Search In Early O3 Ligo Data For Continuous Gravitational-Wave Signals From Unknown Neutron Stars In Binary Systems, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, K. E. Ramirez, W. H. Wang
All-Sky Search In Early O3 Ligo Data For Continuous Gravitational-Wave Signals From Unknown Neutron Stars In Binary Systems, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, K. E. Ramirez, W. H. Wang
Physics and Astronomy Faculty Publications and Presentations
Rapidly spinning neutron stars are promising sources of continuous gravitational waves. Detecting such a signal would allow probing of the physical properties of matter under extreme conditions. A significant fraction of the known pulsar population belongs to binary systems. Searching for unknown neutron stars in binary systems requires specialized algorithms to address unknown orbital frequency modulations. We present a search for continuous gravitational waves emitted by neutron stars in binary systems in early data from the third observing run of the Advanced LIGO and Advanced Virgo detectors using the semicoherent, GPU-accelerated, BinarySkyHough pipeline. The search analyzes the most sensitive frequency …
The Primary Volatile Composition Of Comet C/2015 Er61 (Panstarrs), Aaron Butler
The Primary Volatile Composition Of Comet C/2015 Er61 (Panstarrs), Aaron Butler
Theses
In the outer edges of the solar system exist two regions: the Kuiper belt and Oort cloud. These two regions have a high amount of icy bodies (comets) orbiting the Sun. Comets located within the Oort cloud and Kuiper belt contain an ancient codex to the solar systems contents, before the formation of our solar system. Presented are near-infrared, high-resolution (λ/Δλ ~40000) data obtained from the immersion-grating echelle spectrograph iSHELL at the 3m NASA Infrared Telescope Facility (IRTF) in Maunakea, Hawaii of the Oort cloud comet C/2015 ER61 (PANSTARRS). Observations took place on April 15 and 17 in 2017 while …
Discovering New Strong Gravitational Lenses In The Desi Legacy Imaging Surveys, Xiaosheng Huang, Christopher Storfer, A. Gu, V. Ravi, A. Pilon, W. Sheu, R. Venguswamy, S. Bankda, A. Dey, M. Landriau, D. Lang, A. Meisner, J. Moustakas, A. D. Myers, R. Sajith, E. F. Schlafly, D. J. Schlegel
Discovering New Strong Gravitational Lenses In The Desi Legacy Imaging Surveys, Xiaosheng Huang, Christopher Storfer, A. Gu, V. Ravi, A. Pilon, W. Sheu, R. Venguswamy, S. Bankda, A. Dey, M. Landriau, D. Lang, A. Meisner, J. Moustakas, A. D. Myers, R. Sajith, E. F. Schlafly, D. J. Schlegel
Physics and Astronomy
We have conducted a search for new strong gravitational lensing systems in the Dark Energy Spectroscopic Instrument Legacy Imaging Surveys’ Data Release 8. We use deep residual neural networks, building on previous work presented in Huang et al. (2020). These surveys together cover approximately one third of the sky visible from the northern hemisphere, reaching a z-band AB magnitude of ∼ 22.5. We compile a training sample that consists of known lensing systems as well as non-lenses in the Legacy Surveys and the Dark Energy Survey. After applying our trained neural networks to the survey data, we visually inspect and …
Stability Of A Regular Black Holes Thin-Shell Wormhole In Reissner-Nordstrom - De Sitter Space-Time, A. Eid
Stability Of A Regular Black Holes Thin-Shell Wormhole In Reissner-Nordstrom - De Sitter Space-Time, A. Eid
Applications and Applied Mathematics: An International Journal (AAM)
The dynamics regular black holes thin shell wormhole with a phantom energy equation of state in Reissner-Nordstrom - De sitter space-time is studied using the Darmois-Israel formalism. A mechanical stability analysis is carried out by using the standard perturbation method. The stable and unstable static solution depends on the suitable value of parameters.
Mountaintop Neutrino Detection: A Nu(Tau) Concept, Caroline E. Paciaroni
Mountaintop Neutrino Detection: A Nu(Tau) Concept, Caroline E. Paciaroni
Physics
High-energy neutrinos traveling from the distant universe produce detectable signals at radio frequencies after interacting with the earth or its atmosphere. This is the principle behind a new experiment, the BEamforming Elevated Array for COsmogenic Neutrinos, or BEACON. BEACON will be a high altitude array of antennas that is sensitive to up-going tau neutrinos ($\nu_{\tau}$). These elementary particles serve as sources of information about the extraordinarily high energy events in the universe that create them, and also the laws of particle physics that govern their behavior. This report details the construction of a transient detector used to characterize site locations …
Gamma-Ray Burst Classification: New Insights From Mining Pulse Data, Stanley Mcafee, Jon Hakkila
Gamma-Ray Burst Classification: New Insights From Mining Pulse Data, Stanley Mcafee, Jon Hakkila
Journal of the South Carolina Academy of Science
Despite being the most energetic electromagnetic explosions in the universe, gamma-ray bursts (GRBs) are still poorly understood. The literature recognizes two potentially different types of GRB progenitors, although statistical data suggest the existence of three GRB classes. Reliable inference of GRB physics depends on the identification of appropriate classification attributes, as well as on the statistical classification techniques used. It has recently been shown that pulses are the basic unit of GRB emission. We use new data describing GRB pulse characteristics, in conjunction with data mining tools, to provide a more reliable gamma-ray burst classification system and place additional constraints …
Using An Astrophysical Model To Characterize Nuclear Dust, Anita N. Dunsmore
Using An Astrophysical Model To Characterize Nuclear Dust, Anita N. Dunsmore
Theses and Dissertations
Dust clouds resulting from nuclear explosions are complex phenomena, and knowledge on how they form is lacking. Noting the similarities between supernovae and nuclear explosions led to the concept of modeling a nuclear dust cloud using a supernova simulation. MOCASSIN uses a Monte Carlo approach to model photons traveling through a dust cloud, allowing the cloud's characteristics to be discovered by comparing an observed spectrum to a calculated one and then changing input values to make the spectra match. Data files describing two nuclear fireballs of varying yields were created and analyzed using MOCASSIN, but yielded zero energy spectra. After …
Gw170817: Implications For The Stochastic Gravitational-Wave Background From Compact Binary Coalescences, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Gw170817: Implications For The Stochastic Gravitational-Wave Background From Compact Binary Coalescences, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
The LIGO Scientific and Virgo Collaborations have announced the event GW170817, the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star component will add to the contribution from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude ΩGW( …
Studying The Reaction 34ar(Alpha,P)37k And Its Impact On Xrb Nucleosynthesis And Observables, Amber C. Lauer
Studying The Reaction 34ar(Alpha,P)37k And Its Impact On Xrb Nucleosynthesis And Observables, Amber C. Lauer
LSU Doctoral Dissertations
Type I X-Ray bursts (XRB’s) are a site of nucleosynthesis for some proton-rich elements up to A=100. These stellar explosions occur on the surface of a neutron star in a Low- Mass X-ray Binary accreting H- and He-rich material. During accretion nuclear burning occurs through stable processes such as the hot CNO (HCNO) cycles, but at some critical accretion condition the the HCNO cycles are bypassed through a breakout reaction. This triggers the thermonuclear runaway of the XRB. During the burst, nucleosynthesis on certain proton-rich nuclei, called (α, p) waiting points, can stall which could stall the energy generation and …
Gw170817: Observation Of Gravitational Waves From A Binary Neutron Star Inspiral, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Gw170817: Observation Of Gravitational Waves From A Binary Neutron Star Inspiral, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
On August 17, 2017 at 12-41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0 x 104 years. We infer the component masses of the binary to be between 0.86 and 2.26 M⊙, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17-1.60 M …
Fractal Holography: A Geometric Re-Interpretation Of Cosmological Large Scale Structure, Jonas R. Mureika
Fractal Holography: A Geometric Re-Interpretation Of Cosmological Large Scale Structure, Jonas R. Mureika
Jonas Mureika
The fractal dimension of large-scale galaxy clustering has been demonstrated to be roughly DF∼2 from a wide range of redshift surveys. If correct, this statistic is of interest for two main reasons: fractal scaling is an implicit representation of information content, and also the value itself is a geometric signature of area. It is proposed that the fractal distribution of galaxies may thus be interpreted as a signature of holography (``fractal holography''), providing more support for current theories of holographic cosmologies. Implications for entropy bounds are addressed. In particular, because of spatial scale invariance in the matter distribution, …
Primordial Black Hole Evaporation And Spontaneous Dimensional Reduction, Jonas R. Mureika
Primordial Black Hole Evaporation And Spontaneous Dimensional Reduction, Jonas R. Mureika
Jonas Mureika
Several different approaches to quantum gravity suggest the effective dimension of spacetime reduces from four to two near the Planck scale. In light of such evidence, this Letter re-examines the thermodynamics of primordial black holes (PBHs) in specific lower-dimensional gravitational models. Unlike in four dimensions, (1 + 1)-D black holes radiate with power P ∼ M2BH, while it is known no (2+1)-D (BTZ) black holes can exist in a non-anti-de Sitter universe. This has important relevance to the PBH population size and distribution, and consequently on cosmological evolution scenarios. The number of PBHs that have evaporated to …
Upper Limits On The Stochastic Gravitational-Wave Background From Advanced Ligo's First Observing Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Upper Limits On The Stochastic Gravitational-Wave Background From Advanced Ligo's First Observing Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
A wide variety of astrophysical and cosmological sources are expected to contribute to a stochastic gravitational-wave background. Following the observations of GW150914 and GW151226, the rate and mass of coalescing binary black holes appear to be greater than many previous expectations. As a result, the stochastic background from unresolved compact binary coalescences is expected to be particularly loud. We perform a search for the isotropic stochastic gravitational-wave background using data from Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. The data display no evidence of a stochastic gravitational-wave signal. We constrain the dimensionless energy density of gravitational waves …
Gamma/Hadron Separation For The Hawc Observatory, Michael J. Gerhardt
Gamma/Hadron Separation For The Hawc Observatory, Michael J. Gerhardt
Dissertations, Master's Theses and Master's Reports
The High-Altitude Water Cherenkov (HAWC) Observatory is a gamma-ray observatory sensitive to gamma rays from 100 GeV to 100 TeV with an instantaneous field of view of ~2 sr. It is located on the Sierra Negra plateau in Mexico at an elevation of 4,100 m and began full operation in March 2015. The purpose of the detector is to study relativistic particles that are produced by interstellar and intergalactic objects such as: pulsars, supernova remnants, molecular clouds, black holes and more. To achieve optimal angular resolution, energy reconstruction and cosmic ray background suppression for the extensive air showers detected by …
Spectroscopic And Spectro-Astrometric Analysis Of T Tauri Stars, Logan Ryan Brown
Spectroscopic And Spectro-Astrometric Analysis Of T Tauri Stars, Logan Ryan Brown
Dissertations
To understand our own solar origins, we must investigate the composition of the protoplanetary disk from which the solar system formed. To infer this, we study analogs to the early solar system called T Tauri stars. These objects are low-mass, pre-main sequence stars surrounded by circumstellar disks of material from which planets are believed to form. We present high-resolution, near-infrared spectroscopic data for the T Tauri stars DR Tau and AA Tau using NIRSPEC at the Keck II telescope. For DR Tau, a spectro-astrometric analysis was performed, obtaining sub-seeing spatial information on water emission. Alongside a disk model, we constrained …