Physical Processes Commons^™

Dark Matter Detection Materials, James E. Harrison Iv

PANDION: The Osprey Journal of Research and Ideas

The purpose of this paper is to review the different methods and materials used in the detection of dark matter. Special attention is given to materials in the solid state, but other materials are briefly mentioned for the sake of completeness. After a review, we discuss the viability of each material as a detector, and determine what advantages each material has, and what method of detection works best for each material. We conclude by discussing the potential outcomes of a null detection.

Transmission Telescope Optical Dynamic Alignment, Viviana Vladutescu, Aaron J. Swank, Dzu K. Le, Calvin R. Robinson, O. Scott Sands

Publications and Research

The Integrated Radio Optical Communication System (iROC) is designed to transmit data between Mars and Earth by means of radio waves at 32.67 GHz (Ka band) and laser beam (LB) at 1550 nm, both transmitted via a combined telescope/antenna called a teletenna. The iROC terminal will provide “beaconless” operations to allow full function from the outer planets. In order to point without the aid of an uplink beacon, the proof of concept presented here is addressing the need for an accurate determination and control of the relative position of the LB with respect to a reference star.

The experiment presented …

A Mechanical Model For Magnetized Relativistic Blastwaves, Shunke Ai, Bing Zhang

Physics & Astronomy Faculty Research

The evolution of a relativistic blastwave is usually delineated under the assumption of pressure balance between forward- and reverse-shocked regions. However, such a treatment usually violates the energy conservation law, and is inconsistent with existing magnetohydrodynamic numerical simulation results. A mechanical model of non-magnetized blastwaves was proposed in previous work to solve the problem. In this paper, we generalize the mechanical model to the case of a blastwave driven by an ejecta with an arbitrary magnetization parameter $\sigma_{\rm ej}$. We test our modified mechanical model by considering a long-lasting magnetized ejecta and found that it is much better than the …

Systematical Uncertainties In The Measurement Of A Gamma-Ray Burst’S Isotropic Equivalent Energy, Kimberly Zoldak

Graduate Theses and Dissertations

Gamma-ray Bursts (GRBs) are the most energetic and luminous explosions in the Universe since the Big Bang, enabling them to be observed out to extremely large redshifts (z~9). Consequently, this makes them a promising cosmological standard candle candidate. Unfortunately, however, they have proven to be quite challenging to standardize. The GRB community has worked tirelessly at this task, and to date, has put forth several luminosity-distance relations, some more propitious than others. The most prevailing problem with these relations is in their sizable amount of scatter, likely due to measurement inconsistencies and errors in the variables they employ. This arises …

Image Analysis Of Charged Bimodal Colloidal Systems In Microgravity., Adam J. Cecil

Electronic Theses and Dissertations

Colloids are suspensions of two or more phases and have been topics of research for advanced, tunable materials for decades. Stabilization of colloids is typically attributed to thermodynamic mechanisms; however, recent studies have identified transport or entropic mechanisms that can potentially stabilize a thermodynamically unstable colloidal system. In this study, suspensions of silsesquioxane microparticles and zirconia nanoparticles were dispersed in a nitric acid solution and allowed to aggregate for 8-12 days in microgravity aboard the International Space Station. The suspensions were subsequently imaged periodically at 2.5x magnification. Due to the inadequacy of existing image analysis programs, the python package “Colloidspy” …

Testing Spiral Density-Wave Theory In Disk Galaxies Using Multi-Wavelength Image Data, Star Formation History Maps And Spatially Resolved Stellar Clusters, Mohamed Shameer Abdeen

Graduate Theses and Dissertations

Studying galaxy structures using different wavebands enables us to observe a varietyof intrinsic galactic features and to test the validity of underlying theories in detail. Density wave theory, originally proposed by C.C. Lin and F. Shu (Lin & Shu 1964), explains the nature of the spiral arm patterns in disk galaxies as density waves that propagate through the galactic disk. From spiral galaxies to the rings of Saturn, density wave theory has had success in providing qualitative explanations of disk dynamics. However, it is now widely believed that galactic disks are dissipative systems which raises the question of whether they …

Experimental Constraint On Axionlike Particles Over Seven Orders Of Magnitude In Mass, Tanya S. Roussy, Daniel A. Palken, William B. Cairncross, Benjamin M. Brubaker, Daniel N. Gresh, Matt Grau, Kevin C. Cossel, Kia Boon Ng, Yuval Shagam, Yan Zhou, Victor V. Flambaum, Konrad W. Lehnert, Jun Ye, Eric A. Cornell

Physics & Astronomy Faculty Research

We use our recent electric dipole moment (EDM) measurement data to constrain the possibility that the HfF+ EDM oscillates in time due to interactions with candidate dark matter axionlike particles (ALPs). We employ a Bayesian analysis method which accounts for both the look-elsewhere effect and the uncertainties associated with stochastic density fluctuations in the ALP field. We find no evidence of an oscillating EDM over a range spanning from 27 nHz to 400 mHz, and we use this result to constrain the ALP-gluon coupling over the mass range 10-22-10-15 eV. This is the first laboratory constraint on the ALP-gluon coupling …

The James Webb Space Telescope And Scientific Progress, Robert Astle

Quest

Independent Research Paper

Research in progress for PHYS 2425: University Physics I

Faculty Mentor: Raji Kannampuzha, Ph.D.

The following paper represents research work done by students in University Physics 2425, the first half of a two-semester introductory course in physics. It is a calculus- based physics course, intended primarily for physics, chemistry, math, and engineering majors. Students are introduced to the concept of academic research by learning to ask research-focused questions and then use the library resources to pursue outside research to find answers. For this assignment, students are asked to investigate a physical science, biological science, or technology problem …

A Multi-Wavelength Study Of The Disk Winds And Their Role In The Agn Studies, Maryam Dehghanian

Theses and Dissertations--Physics and Astronomy

Active galactic nuclei (AGNs) are located at the centers of massive galaxies and are the most luminous objects in the universe. Each AGN embeds a super-massive black hole which produces outflows of gas, or winds. These winds are important because they provide a reasonable physical basis for the connections between the black hole and the properties of their host galaxy. While AGNs have been extensively studied, several fundamental questions about them are yet to be answered. These include the structure and dynamics of the central source and their winds, and questions regarding the evolution of these galaxies.

NGC 5548 is …

Exclusion Statistics For Particles With A Discrete Spectrum, Stéphane Ouvry, Alexios P. Polychronakos

Publications and Research

We formulate and study the microscopic statistical mechanics of systems of particles with exclusion statistics in a discrete one-body spectrum. The statistical mechanics of these systems can be expressed in terms of effective single-level grand partition functions obeying a generalization of the standard thermodynamic exclusion statistics equation of state. We derive explicit expressions for the thermodynamic potential in terms of microscopic cluster coefficients and show that the mean occupation numbers of levels satisfy a nesting relation involving a number of adjacent levels determined by the exclusion parameter. We apply the formalism to the harmonic Calogero model and point out a …

Evidence For Electron Energization Accompanying Spontaneous Formation Of Ion Acceleration Regions In Expanding Plasmas, Evan M. Aguirre, Rikard Bodin, Neng Yin, Timothy N. Good, Earl E. Scime

Physics and Astronomy Faculty Publications

We report experiments conducted in an expanding argon plasma generated in the inductive mode of a helicon source in the Hot hELIcon eXperiment–Large Experiment on Instabilities and Anisotropies facility. As the neutral gas pressure increases, the supersonic ion acceleration weakens. Increasing neutral pressure also alters the radial profile of electron temperature, density, and plasma potential upstream of the plasma expansion region. Langmuir probe measurements of the electron energy probability function (EEPF) show that heating of electrons at the plasma edge by RF fields diminishes with increasing gas pressure, yielding a plasma with a centrally peaked electron temperature, and flat potential …

Tidal Locking And The Gravitational Fold Catastrophe, Andrea Ferroglia, Miguel C. N. Fiolhais

Publications and Research

The purpose of this work is to study the phenomenon of tidal locking in a pedagogical framework by analyzing the effective gravitational potential of a two-body system with two spinning objects. It is shown that the effective potential of such a system is an example of a fold catastrophe. In fact, the existence of a local minimum and saddle point, corresponding to tidally locked circular orbits, is regulated by a single dimensionless control parameter that depends on the properties of the two bodies and on the total angular momentum of the system. The method described in this work results in …

Gas Dynamics In Galaxy Clusters And Galaxies, Danial Ahmad Ariffin Lee

Student Works (2020-2029)

This thesis presents the results from a search for Neutral Hydrogen (HI) for the central region of the galaxy clusters A426 and A1367 using a 7m radio telescope. The resulting beam is substantially larger than previous studies, covering the central 2.5–3 Mpc diameter of these clusters. The detection of HI allows the mass of atomic gas associated with the cluster core to be estimated. The HI is not associated with any particular cluster member but present due to ram pressure and tidal stripping or recombination of intracluster gas. Overall results have revealed the presence of a significant mass of atomic …

Solar Radio Burst Type Ii And Iii With Half Wave Dipole Antenna, Mohd Pauzi Farah Aqilah

Student Works (2020-2029)

An investigation into the physics of solar radio burst type II was done to understand the frequency gap between its fundamental and harmonic emissions that happen as aftershocks of Coronal Mass Ejection (CME). Up until now, the evolution of type II and its associated coronal wave still remain a mystery. Hazardous CME study upholds its fore coming danger to human and technology. This work also addresses the issue of the lack of spatial resolution of previous solar radio burst type II studies. An instrument produced by ETH Zürich namely the Compound Astronomical Low-cost Low-frequency Instrument for Spectroscopy and Transportable Spectrometers …

A Fast Radio Burst Discovered In Fast Drift Scan Survey, Weiwei Zhu, Di Li, Rui Luo, Chenchen Miao, Bing Zhang, Laura Spitler, Duncan Lorimer, Michael Kramer, David Champion, Youling Yue, Andrew Cameron, Marilyn Cruces, Ran Duan, Yi Feng, Jun Han, George Hobbs, Chenhui Niu, Jiarui Niu, Zhichen Pan, Lei Qian, Dai Shi, Ningyu Tang, Pei Wang, Hongfeng Wang, Mao Yuan, Lei Zhang, Xinxin Zhang, Shuyun Cao, Li Feng, Hengqian Gan, Long Gao

Physics & Astronomy Faculty Research

We report the discovery of a highly dispersed fast radio burst (FRB), FRB 181123, from an analysis of ~1500 hr of drift scan survey data taken using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The pulse has three distinct emission components, which vary with frequency across our 1.0–1.5 GHz observing band. We measure the peak flux density to be... (See full abstract in article).

Dust Condensation In Evolving Discs And The Composition Of Planetary Building Blocks, Min Li, Shichun Huang, Michail I. Petaev, Zhaohuan Zhu, Jason H. Steffen

Physics & Astronomy Faculty Research

Partial condensation of dust from the Solar nebula is likely responsible for the diverse chemical compositions of chondrites and rocky planets/planetesimals in the inner Solar system. We present a forward physical–chemical model of a protoplanetary disc to predict the chemical compositions of planetary building blocks that may form from such a disc. Our model includes the physical evolution of the disc and the condensation, partial advection, and decoupling of the dust within it. The chemical composition of the condensate changes with time and radius. We compare the results of two dust condensation models: one where an element condenses when the …

Towards Gross-Pitaevskiian Description Of Solar System & Galaxies, Florentin Smarandache, Victor Christianto, Yunita Umniyati

Branch Mathematics and Statistics Faculty and Staff Publications

In this paper, we argue that Gross-Pitaevskii model can be a more complete description of both solar system and spiral galaxies, especially taking into account the nature of chirality and vortices in galaxies. We also hope to bring out some correspondence among existing models, e.g., the topological vortex approach, Burgers equation in the light of KAM theory, and the Cantorian Navier-Stokes approach. We hope further investigation can be done around this line of approach.

Automated Spectroscopic Detection And Mapping Using Alma And Machine Learningtechniques, Steven Cocke, Andrew Wilkins, Josephine Mcdaniel, John Santerre, Conor Nixon

SMU Data Science Review

In this paper we present a methodology for automating theclassification of spectrally resolved observations of multiple emissionlines with the Atacama Large Millimeter/submillimeter Array (ALMA).Molecules in planetary atmospheres emit or absorb different wavelengthsof light thereby providing a unique signature for each species. ALMAdata were taken from interferometric observations of Titan made be-tween UT 2012 July 03 23:22:14 and 2012 July 04 01:06:18 as part ofALMA project 2011.0.00319.S. We first employed a greedy set cover algorithm to identify the most probable molecules that would reproducethe set of frequencies with respective flux greater than 3σaway from themean. We then selected a subset of …

Extended Gamma Analysis Of Snr G330.2 + 1.0, Abagael Barba, John W. Hewitt

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Analyzing gamma rays is an important aspect of modern astronomy and astrophysics, for they are the most powerful bands of energy on the electromagnetic spectrum. Comprehending gamma rays allows for deeper understanding of countless phenomena within our universe, such as cosmic rays. Cosmic rays are high energy particles thought to be formed via extremely violent explosions within our universe. These accelerated particles mirror conditions present in a supernova. A supernova is what occurs when a star at least 8 times as massive as our sun reaches the end of its lifespan and bursts. These explosions are the most powerful events …

Global 3d Radiation Magnetohydrodynamic Simulations For Fu Ori's Accretion Disc And Observational Signatures Of Magnetic Fields, Zhaohuan Zhu, Yan-Fei Jiang, James M. Stone

Physics & Astronomy Faculty Research

FU Ori is the prototype of FU Orionis systems that are outbursting protoplanetary discs. Magnetic fields in FU Ori’s accretion discs have previously been detected using spectropolarimetry observations for Zeeman effects. We carry out global radiation ideal MHD simulations to study FU Ori’s inner accretion disc. We find that (1) when the disc is threaded by vertical magnetic fields, most accretion occurs in the magnetically dominated atmosphere at z ∼ R, similar to the ‘surface accretion’ mechanism in previous locally isothermal MHD simulations. (2) A moderate disc wind is launched in the vertical field simulations with a terminal speed of …