The Heliosphere As Seen In Tev Cosmic Rays,
2016
Florida Institute of Technology
The Heliosphere As Seen In Tev Cosmic Rays, Ming Zhang, Nikolai Pogorelov
Aerospace, Physics, and Space Science Faculty Publications
Measurements from several cosmic-ray air shower experiments reveal that the anisotropy of TeV cosmic-ray flux does not agree with a dipole pattern commonly expected from the Compton–Getting effect or from the diffusion of cosmic rays in Galactic magnetic fields. TeV cosmic-ray anisotropy maps often show fine features, some of which are slightly time-dependent. Because the size of the heliosphere is larger than the gyroradius of TeV cosmic rays in the interstellar magnetic field, the electric and magnetic fields of the heliosphere may distort the pattern of cosmic-ray anisotropy that one would see in the local interstellar medium without the presence …
Measurement Of Higher Cumulants Of Net-Charge Multiplicity Distributions In Au + Au Collisions At √Snn =7.7-200 Gev,
2016
University of Colorado, Boulder
Measurement Of Higher Cumulants Of Net-Charge Multiplicity Distributions In Au + Au Collisions At √Snn =7.7-200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, Phenix Collaboration
Aerospace, Physics, and Space Science Faculty Publications
We report the measurement of cumulants (Cn,n=1,...,4) of the net-charge distributions measured within pseudorapidity (|η|<0.35) in Au+Au collisions at √sNN=7.7-200GeV with the PHENIX experiment at the Relativistic Heavy Ion Collider. The ratios of cumulants (e.g., C₁/C₂, C₃/C₁) of the net-charge distributions, which can be related to volume independent susceptibility ratios, are studied as a function of centrality and energy. These quantities are important to understand the quantum-chromodynamics phase diagram and possible existence of a critical end point. The measured values are very well described by expectation from negative binomial distributions. We do not observe any nonmonotonic behavior in the ratios of the cumulants as a function of collision energy. The measured values of C₁/C₂ and C₃/C₁ can be directly compared to lattice quantum-chromodynamics calculations and thus allow extraction of both the chemical freeze-out temperature and the baryon chemical potential at each center-of-mass energy. The extracted baryon chemical potentials are in excellent agreement with a thermal-statistical analysis model.
The Puzzling Properties Of The Magnetic O Star Tr16-22,
2016
Université de Liège
The Puzzling Properties Of The Magnetic O Star Tr16-22, Yaël Nazé, Rodolfo Barbá, Stefano Bagnulo, Nidia Morrell, Roberto Gamen, Véronique Petit, Coralie Neiner
Aerospace, Physics, and Space Science Faculty Publications
Context. The detection of bright, hard, and variable X-ray emission in Tr16-22 prompted spectropolarimetric observations of this star, which in turn led to the discovery of a surface magnetic field. Aims. We want to further constrain the properties of this star, in particular to verify whether X-ray variations are correlated to changes in optical emission lines and magnetic field strength, as expected from the oblique rotator model that is widely accepted for magnetic O stars. Methods. We have obtained new low-resolution spectropolarimetric and long-term high-resolution spectroscopic monitoring of Tr16-22, and we also analyse new, serendipitous X-ray data. Results. The new …
Evidence Of Magnetic Field Decay In Massive Main-Sequence Stars,
2016
Austrian Academy of Sciences
Evidence Of Magnetic Field Decay In Massive Main-Sequence Stars, Luca Fossati, Fabian R.N. Schneider, Norberto Castro, Norbert Langer, Sergio Simón-Díaz, André Luís Müller, Alex De Koter, Thierry Morel, Véronique Petit, Hugues Sana, Gregg A. Wade
Aerospace, Physics, and Space Science Faculty Publications
A significant fraction of massive main-sequence stars show strong, large-scale magnetic fields. The origin of these fields, their lifetimes, and their role in shaping the characteristics and evolution of massive stars are currently not well understood. We compile a catalogue of 389 massive main-sequence stars, 61 of which are magnetic, and derive their fundamental parameters and ages. The two samples contain stars brighter than magnitude 9 in the V-band and range in mass between 5 and 100 M⊙. We find that the fractional main-sequence age distribution of all considered stars follows what is expected for a magnitude limited sample, while …
A Search For Brief Optical Flashes Associated With The Seti Target Kic 8462852,
2016
University of Utah
A Search For Brief Optical Flashes Associated With The Seti Target Kic 8462852, A U. Abeysekara, Jamie A. Holder
Aerospace, Physics, and Space Science Faculty 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 1 photon m-2, is found. We also discuss the potential use of imaging atmospheric Cherenkov telescope arrays in searching for extremely short duration optical transients in general.
Scaling Properties Of Fractional Momentum Loss Of High- Pt Hadrons In Nucleus-Nucleus Collisions At √Snn From 62.4 Gev To 2.76 Tev,
2016
University of Colorado, Boulder
Scaling Properties Of Fractional Momentum Loss Of High- Pt Hadrons In Nucleus-Nucleus Collisions At √Snn From 62.4 Gev To 2.76 Tev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, S. Rembeczki, Phenix Collaboration
Aerospace, Physics, and Space Science Faculty Publications
Measurements of the fractional momentum loss (Sloss ≡ δpT/pT) of high-transverse-momentum-identified hadrons in heavy-ion collisions are presented. Using π⁰ in Au+Au and Cu+Cu collisions at √sNN=62.4 and 200 GeV measured by the PHENIX experiment at the Relativistic Heavy Ion Collider and and charged hadrons in Pb+Pb collisions measured by the ALICE experiment at the Large Hadron Collider, we studied the scaling properties of Sloss as a function of a number of variables: the number of participants, Npart, the number of quark participants, Nqp, the charged-particle density, dNch/dη, and the Bjorken energy density times the equilibration time, ᵋᵦjτ₀. We find that …
Transverse Energy Production And Charged-Particle Multiplicity At Midrapidity In Various Systems From √Snn =7.7 To 200 Gev,
2016
University of Colorado, Boulder
Transverse Energy Production And Charged-Particle Multiplicity At Midrapidity In Various Systems From √Snn =7.7 To 200 Gev, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Klaus Dehmelt, Marcus Hohlmann, S. Rembeczki
Aerospace, Physics, and Space Science Faculty Publications
Measurements of midrapidity charged-particle multiplicity distributions, dNch/dη, and midrapidity transverse-energy distributions, dET/dη, are presented for a variety of collision systems and energies. Included are distributions for Au+Au collisions at sNN=200, 130, 62.4, 39, 27, 19.6, 14.5, and 7.7 GeV, Cu+Cu collisions at √sNN=200 and 62.4 GeV, Cu+Au collisions at √sNN=200 GeV, U+U collisions at √sNN=193 GeV, d+Au collisions at √sNN=200 GeV, ³He+Au collisions at √sNN=200 GeV, and p+p collisions at √sNN=200 GeV. Centrality-dependent distributions at midrapidity are presented in terms of the number of nucleon participants, Npart, and the number of constituent quark participants, Nqp. For all A+A collisions down …
Transit Timing Observations From Kepler. Ix. Catalog Of The Full Long-Cadence Data Set,
2016
Tel Aviv University
Transit Timing Observations From Kepler. Ix. Catalog Of The Full Long-Cadence Data Set, Tomer Holczer, Tsevi Mazeh, Gil Nachmani, Daniel Jontof-Hutter, Eric B. Ford, Daniel Fabrycky, Darin Ragozzine, Mackenzie Kane, Jason H. Steffen
Aerospace, Physics, and Space Science Faculty Publications
We present a new transit timing catalog of 2599 Kepler Objects of Interest (KOIs), using the PDC-MAP long-cadence light curves that include the full 17 quarters of the mission (ftp://wise-ftp.tau.ac.il/pub/tauttv/TTV/ver-112). The goal is to produce an easy-to-use catalog that can stimulate further analyses of interesting systems. For 779 KOIs with high enough S/N, we derived the timing, duration, and depth of 69,914 transits. For 1820 KOIs with lower SNR, we derived only the timing of 225,273 transits. After removal of outlier timings, we derived various statistics for each KOI that were used to indicate significant variations. Including systems found by …
Powerful Activity In The Bright Ages. I. A Visible/Ir Survey Of High Redshift 3c Radio Galaxies And Quasars,
2016
Space Telescope Science Institute
Powerful Activity In The Bright Ages. I. A Visible/Ir Survey Of High Redshift 3c Radio Galaxies And Quasars, Bryan Hilbert, Eric S. Perlman
Aerospace, Physics, and Space Science Faculty Publications
We present new rest-frame UV and visible observations of 22 high-z (1 < z < 2.5) 3C radio galaxies and QSOs obtained with the Hubble Space Telescope's Wide Field Camera 3 instrument. Using a custom data reduction strategy in order to assure the removal of cosmic rays, persistence signal, and other data artifacts, we have produced high-quality science-ready images of the targets and their local environments. We observe targets with regions of UV emission suggestive of active star formation. In addition, several targets exhibit highly distorted host galaxy morphologies in the rest frame visible images. Photometric analyses reveal that brighter QSOs generally tend to be redder than their dimmer counterparts. Using emission line fluxes from the literature, we estimate that emission line contamination is relatively small in the rest frame UV images for the QSOs. Using archival VLA data, we have also created radio map overlays for each of our targets, allowing for analysis of the optical and radio axes alignment.
The Detection And Characterization Of Extrasolar Planets,
2016
University at Albany, State University of New York
The Detection And Characterization Of Extrasolar Planets, Zachary Richards
Legacy Theses & Dissertations (2009 - 2024)
The study of extra-solar planets (exoplanets) is a rapidly expanding field, which aims to detect, characterize, and understand how other planetary systems form and behave. Observing an exoplanet transit its host star allows us to detect the exoplanet in the light curve. As an exoplanet transits, there will be a dip in the total flux (light per unit area) of the host star visible in the light curve. While observing an exoplanet transit, several photometric effects may influence the light curve. We consider the following photometric effects: reflected light, Doppler boosting (beaming), thermal emission, and ellipsoidal variation. This study relies …
Bayesian Model Testing Of Models For Ellipsoidal Variation On Stars Due To Hot Jupiters,
2016
University at Albany, State University of New York
Bayesian Model Testing Of Models For Ellipsoidal Variation On Stars Due To Hot Jupiters, Anthony Gai
Legacy Theses & Dissertations (2009 - 2024)
A massive planet closely orbiting its host star creates tidal forces that distort the typically spherical stellar surface. These distortions, known as ellipsoidal variations, result in variations in the photometric flux emitted by the star, which can be detected by the Kepler Space Telescope. Currently, there exist several models describing such variations and their effect on the photometric fux [1] [2] [3] [4]. By using Bayesian model testing in conjunction with the Bayesian-based exoplanet characterization software package EXONEST [4] [5] [6], the most probable representation for ellipsoidal variations was determined for synthetic data and two systems with confirmed hot Jupiter …
Mystery Of The Moon's Origin,
2016
University of North Florida
Mystery Of The Moon's Origin, Abubakr Hassan
UNF Undergraduate Capstone Projects and Honors Theses
The dominant theory of the moon’s origin is the Giant Impact Hypothesis, which states that the moon formed when a Mars-sized object - named Theia - impacted the proto-Earth early in the solar system’s formation, with the resulting material contributing to the formation of the Moon. Using models of planetary development and the solar system’s formation, we attempt to answer where the impactor - Theia - might have originated from. We conclude that the Asteroid belt is a likely location for Theia’s formation, and we find that the parameters associated with this point of origin may help advance other models …
Characterizing Crop Photomultiplier Tube Behavior At 1000 Volts,
2016
University of Nebraska-Lincoln
Characterizing Crop Photomultiplier Tube Behavior At 1000 Volts, Zachary T. Smith
UCARE: Research Products
In an effort to prolong the lifetime of their Photomultiplier tubes (PMTs), the Cosmic Ray Observatory Project (CROP) made the decision to begin operating the PMTs at an operating voltage of 1000 Volts. The aim of this project was to characterize the fundamental behavior of the PMTs at this operating voltage using several tests. These tests include determining the optimal threshold level of the PMTs, the PMT efficiency, and the time stability of the PMT's output.
Data From: How Uncertainty In The Neutral Wind Limits The Accuracy Of Ionospheric Modeling And Forecasting,
2016
Utah State University
Data From: How Uncertainty In The Neutral Wind Limits The Accuracy Of Ionospheric Modeling And Forecasting, Michael David, Jan Sojka, Robert W. Schunk
Browse all Datasets
Output files from runs of the TDIM ionospheric model used for the figures and calculations in the article in JGR Space Physics.
Construction Of An Optical Fiber Strian Gauge,
2016
Eastern Michigan University
Construction Of An Optical Fiber Strian Gauge, Najwa Sulaiman
Master's Theses and Doctoral Dissertations
This project is focused on the construction of an optical fiber strain gauge that is based on a strain gauge described by Butter and Hocker. Our gauge is designed to generate an interference pattern from the signals carried on two bare single-mode fibers that are fastened to an aluminum cantilever. When the cantilever experiences flexural stress, the interference pattern should change. By observing this change, it is possible to determine the strain experienced by the cantilever. I describe the design and construction of our optical fiber strain gauge as well as the characterization of different parts of the apparatus.
Saturn's Rings: Measuring Particle Size Distributions Using Cassini Uvis Occultation Data,
2016
University of Central Florida
Saturn's Rings: Measuring Particle Size Distributions Using Cassini Uvis Occultation Data, Tracy Becker
Electronic Theses and Dissertations
Since its arrival to Saturn in 2004, the Cassini spacecraft has utilized its suite of sophisticated instruments to further our understanding of the Saturnian ring system. We analyze occultation data from Cassini's Ultraviolet Imaging Spectrograph (UVIS) in order to measure the particle size distribution and place limits on the minimum particle sizes in Saturn's rings. Throughout the ring system, particle accretion is countered by collisional and tidal disruption and Keplerian shear. Therefore, the particle size distribution of the rings is continually evolving. The presence of sub-centimeter particles, which have short lifetimes due to these processes, is indicative of ongoing dynamics …
The Encyclopedia Of Neutrosophic Researchers - Vol. 1,
2016
University of New Mexico
The Encyclopedia Of Neutrosophic Researchers - Vol. 1, Florentin Smarandache
Branch Mathematics and Statistics Faculty and Staff Publications
This is the first volume of the Encyclopedia of Neutrosophic Researchers, edited from materials offered by the authors who responded to the editor’s invitation. The authors are listed alphabetically. The introduction contains a short history of neutrosophics, together with links to the main papers and books. Neutrosophic set, neutrosophic logic, neutrosophic probability, neutrosophic statistics, neutrosophic measure, neutrosophic precalculus, neutrosophic calculus and so on are gaining significant attention in solving many real life problems that involve uncertainty, impreciseness, vagueness, incompleteness, inconsistent, and indeterminacy. In the past years the fields of neutrosophics have been extended and applied in various fields, such as: …
Investigation Of Lunar Subsurface Cavities Using Thermal Inertia And Temperature Maximum To Minimum Ratios,
2016
University of Texas at El Paso
Investigation Of Lunar Subsurface Cavities Using Thermal Inertia And Temperature Maximum To Minimum Ratios, Rachel Ann Slank
Open Access Theses & Dissertations
Previous studies have revealed a small number of subsurface cavities, including lava tubes, as well as skylights, lava flow pits, and impact melt pits on the Moon. The interiors of subsurface cavities would have been protected from micrometeorite bombardment, solar radiation, space weathering, and extreme diurnal temperature swings over long periods of geologic time. As a result, subsurface cavities can provide access to pristine crustal samples and stratigraphy. These cavities may also harbor important volatiles, such as water ice, that would enable future exploration missions by relieving many operational constraints, including the supply of propellants and life support. In addition, …
Equation Of State Of A Dense And Magnetized Neutron System,
2016
University of Texas at El Paso
Equation Of State Of A Dense And Magnetized Neutron System, Md Masud
Open Access Theses & Dissertations
Neutron stars (NSs) are the windows to check the validation of physical laws at extreme conditions, for example, at very high densities and strong magnetic fields and thus to reach the equations of state (EoS) for a better understanding of the structure as well as the composition of the NSs. In our investigations, it is found that the system's (NSs) pressure becomes anisotropic due to the breaking of rotational symmetry in the presence of strong magnetic fields, which even can be significantly sufficient to lead into the deformation of NSs or to destroy itself.
Rapid Orbit Refinement Of Potential Near-Earth Objects And Recovery Of Nearly Lost Asteroids,
2016
Columbus State University
Rapid Orbit Refinement Of Potential Near-Earth Objects And Recovery Of Nearly Lost Asteroids, Austin Lantz Caughey
Theses and Dissertations
The Minor Planet Center alerts researchers about potential discoveries of new Near-Earth Objects (NEOs) on their NEO Confirmation Page (NEOCP). Most of these are indeed previously unstudied objects, which must be studied very promptly while initial predictions of their motions are still accurate. My thesis project has focused on the observation of these bodies, and the submission of their measured positions to the MPC within a few hours of observation. Data has been obtained using the Skynet Robotic Telescope Network, including the R-COP telescope in Perth, Australia; the PROMPT 3 telescope in La Serena, Chile; and Yerkes Observatory in Williams …
