Physics Commons^™

Single Particle Tracking: Analysis Techniques For Live Cell Nanoscopy., Peter K. Relich

Physics & Astronomy ETDs

Single molecule experiments are a set of experiments designed specifically to study the properties of individual molecules. It has only been in the last three decades where single molecule experiments have been applied to the life sciences; where they have been successfully implemented in systems biology for probing the behaviors of sub-cellular mechanisms. The advent and growth of super-resolution techniques in single molecule experiments has made the fundamental behaviors of light and the associated nano-probes a necessary concern among life scientists wishing to advance the state of human knowledge in biology. This dissertation disseminates some of the practices learned in …

How Shape Of Simulated Graphene Sheets Affects Debye Scattering Patterns, Lindsay Lesh

Honors Projects

This research is about understanding the structure of a subset of graphitic stardust found in primitive meteorites (e.g. the Murchison meteorite). The carbon grains of interest exhibit a core-rim structure, where the core – with a density less than that of the graphitic rim – comprises the majority of the grain. Previous studies have shown that the cores are comprised primarily of unlayered graphene, and it has been hypothesized that the cores are the result of the rapid freezing (quenching) of a liquid carbon droplet. Electron diffraction is sensitive to small differences in crystal structure and simulated electron diffraction powder …

Sdss-Iv Manga – The Spatially Resolved Transition From Star Formation To Quiescence, Francesco Belfiore, Roberto Maiolino, Claudia Maraston, Eric Emsellem, Matthew A. Bershady, Karen L. Masters, Dmitry Bizyaev, Médéric Boquien, Joel R. Brownstein, Kevin Bundy, Aleksandar M. Diamond-Stanic, Niv Drory, Timothy M. Heckman, David R. Law, Olena Malanushenko, Audrey Oravetz, Kaike Pan, Alexandre Roman-Lopes, Daniel Thomas, Anne-Marie Weijmans, Kyle B. Westfall, Renbin Yan

Physics and Astronomy Faculty Publications

Using spatially resolved spectroscopy from SDSS-IV MaNGA we have demonstrated that low ionization emission-line regions (LIERs) in local galaxies result from photoionization by hot evolved stars, not active galactic nuclei, hence tracing galactic region hosting old stellar population where, despite the presence of ionized gas, star formation is no longer occurring. LIERs are ubiquitous in both quiescent galaxies and in the central regions of galaxies where star formation takes place at larger radii. We refer to these two classes of galaxies as extended LIER (eLIER) and central LIER (cLIER) galaxies, respectively. cLIERs are late-type galaxies primarily spread across the green …

Exotic Statistics For Strings In 4d Bf Theory, John C. Baez, Derek K. Wise, Alissa S. Crans

Alissa Crans

After a review of exotic statistics for point particles in 3d BF theory, and especially 3d quantum gravity, we show that string-like defects in 4d BF theory obey exotic statistics governed by the 'loop braid group'. This group has a set of generators that switch two strings just as one would normally switch point particles, but also a set of generators that switch two strings by passing one through the other. The first set generates a copy of the symmetric group, while the second generates a copy of the braid group. Thanks to recent work of Xiao-Song Lin, we can …

Memory Effects In Brownian Motion, Random Walks Under Confining Potentials, And Relaxation Of Quantum Systems, Matthew Chase

Physics & Astronomy ETDs

This dissertation is a report on a number of distinct topics in the field of non-equilibrium statistical mechanics including the evolution of classical as well as quantum systems.

The evolution of an object that is described by the Ornstein-Uhlenbeck process generalized through a time-nonlocal attraction is considered. The time-nonlocality is taken to be represented in the Langevin description through the presence of memory. Analysis of the Langevin equation is performed for algebraic and delay-type memories. An equivalent \emph{bona-fide} Fokker-Planck equation is constructed.

A random walker subjected to a non-standard confining potential, taken to be a piece-wise linear function, is analyzed. …

Structural Reinforcement Through Liquid Encapsulation, Alin Cristian Chipara, Peter Samora Owuor, Sanjit Bhowmick, Gustavo Brunetto, S. A. Syed Asif, Mircea Chipara, Robert Vajtai, Jun Lou, Douglas S. Galvao, Chandra Sekhar Tiwary

Physics and Astronomy Faculty Publications and Presentations

The liquid inside a solid material is one of the most common composite materials in nature. The interface between solid–liquid plays an important role in unique deformation. Here, model systems of two polymers (polydimethylsiloxane–polyvinylidenefluoride) are used to make sphere of solid with liquid inside it.

Elasticity Of Cylindrical Black Holes, Conrad Pearson

Physics

Black holes are regions of strong gravity, and are often regarded as behaving like drops of fluid. When this line of thought is applied to cylindrical black holes (black cylinders), a mapping can be made between known instabilities for black cylinders and ordinary fluid cylinders. However, this known correlation is increasingly less accurate for lower spatial dimensions, and I seek to correct this discrepancy in this thesis. By considering soft solids instead of pure fluids, elastic energy can be included, which brings us closer to a direct comparison. In improving this mapping, it becomes possible to better understand the behavior …

Tests Of Lorentz Symmetry In The Gravitational Sector, Aurélien Hees, Quentin G. Bailey, Adrien Bourgoin, Hélène Pihan-Le Bars, Christine Guerlin, Christophe Le Poncin-Lafitte

Publications

Lorentz symmetry is one of the pillars of both General Relativity and the Standard Model of particle physics. Motivated by ideas about quantum gravity, unification theories and violations of CPT symmetry, a significant effort has been put the last decades into testing Lorentz symmetry. This review focuses on Lorentz symmetry tests performed in the gravitational sector. We briefly review the basics of the pure gravitational sector of the Standard-Model Extension (SME) framework, a formalism developed in order to systematically parametrize hypothetical violations of the Lorentz invariance. Furthermore, we discuss the latest constraints obtained within this formalism including analyses of the …

Extending The Reach Of Directional Dark Matter Experiments Through Novel Detector Technologies, Nguyen S. Phan

Physics & Astronomy ETDs

Dark matter is believed to comprise over 80% of the matter in the Universe. Its composition could be in the form of weakly interacting massive particles (WIMPs), which are predicted by extensions of the Standard Model, namely supersymmetric theories. Even though hints of its existence were detected in astronomical observations over eighty years ago, its detection through means other than the gravitational influence on observable luminous matter still eludes us.

Currently, there are many ongoing direct detection experiments, that aim to measure the signals left by the elastic scattering of WIMPs with nuclei in the detector target material. The detection …

Sdss-Iv Manga: A Serendipitous Observation Of A Potential Gas Accretion Event, Edmond Cheung, David V. Stark, Song Huang, Kate H. R. Rubin, Lihwai Lin, Christy Tremonti, Kai Zhang, Renbin Yan, Dmitry Bizyaev, Médéric Boquien

Physics and Astronomy Faculty Publications

The nature of warm, ionized gas outside of galaxies may illuminate several key galaxy evolutionary processes. A serendipitous observation by the MaNGA survey has revealed a large, asymmetric Hα complex with no optical counterpart that extends ≈8'' (≈6.3 kpc) beyond the effective radius of a dusty, starbursting galaxy. This Hα extension is approximately three times the effective radius of the host galaxy and displays a tail-like morphology. We analyze its gas-phase metallicities, gaseous kinematics, and emission-line ratios and discuss whether this Hα extension could be diffuse ionized gas, a gas accretion event, or something else. We find …

Sdss-Iv Manga Ifs Galaxy Survey—Survey Design, Execution, And Initial Data Quality, Renbin Yan, Kevin Bundy, David R. Law, Matthew A. Bershady, Brett Andrews, Brian Cherinka, Aleksandar M. Diamond-Stanic, Niv Drory, Nicholas Macdonald, José R. Sánchez-Gallego, Daniel Thomas, David A. Wake, Anne-Marie Weijmans, Kyle B. Westfall, Kai Zhang, Alfonso Aragón-Salamanca, Francesco Belfiore, Dmitry Bizyaev, Guillermo A. Blanc, Michael R. Blanton, Joel Brownstein, Michele Cappellari, Richard D'Souza, Eric Emsellem, Hai Fu, Patrick Gaulme, Mark T. Graham, Daniel Goddard, James E. Gunn, Paul Harding

Physics and Astronomy Faculty Publications

The MaNGA Survey (Mapping Nearby Galaxies at Apache Point Observatory) is one of three core programs in the Sloan Digital Sky Survey IV. It is obtaining integral field spectroscopy for 10,000 nearby galaxies at a spectral resolution of R ~ 2000 from 3622 to 10354 Å. The design of the survey is driven by a set of science requirements on the precision of estimates of the following properties: star formation rate surface density, gas metallicity, stellar population age, metallicity, and abundance ratio, and their gradients; stellar and gas kinematics; and enclosed gravitational mass as a function of radius. We describe …

The Quenching Timescale And Quenching Rate Of Galaxies, Jianhui Lian, Renbin Yan, Kai Zhang, Xu Kong

Physics and Astronomy Faculty Publications

The average star formation rate (SFR) in galaxies has been declining since the redshift of 2. A fraction of galaxies quench and become quiescent. We constrain two key properties of the quenching process: the quenching timescale and the quenching rate among galaxies. We achieve this by analyzing the galaxy number density profile in NUV−u color space and the distribution in NUV−u versus u − i color–color diagram with a simple toy-model framework. We focus on galaxies in three mass bins between 10¹⁰ and 10^10.6 M _⊙. In the NUV−u versus u − i color–color …

Probing Dark Matter-Neutrino Connection Via Indirect Detection Experiments, Bradley Knockel

Physics & Astronomy ETDs

Various evidence reveals that dark matter is a primary component of this universe. The amount of dark matter is known, but its identity is a mystery. To determine its properties, efforts to detect and produce dark matter are underway. Dark matter annihilations throughout the galaxy may produce photons, neutrinos, and cosmic rays. Neutrino and photon detectors may then indirectly detect dark matter by detecting these annihilation products. The annihilation rate, dark matter mass, and dark matter scattering rate off of matter affect the signals received at Earth. These signals can therefore probe the identity of dark matter, especially if dark …

Holographic Renormalization Of Einstein-Maxwell-Dilaton Theories, Bom Soo Kim

Physics and Astronomy Faculty Publications

We generalize the boundary value problem with a mixed boundary condition that involves the gauge and scalar fields in the context of Einstein-Maxwell-Dilaton theories. In particular, the expectation value of the dual scalar operator can be a function of the expectation value of the current operator. The properties are prevalent in a fixed charge ensemble because the conserved charge is shared by both fields through the dilaton coupling, which is also responsible for non-Fermi liquid properties. We study the on-shell action and the stress energy tensor to note practical importances of the boundary value problem. In the presence of the …

The Mid-Infrared Luminosity Evolution And Luminosity Function Of Quasars With Wise And Sdss, Jack Singal

Physics Faculty Publications

We determine the 22 μm luminosity evolution and luminosity function for quasars from a data set of over 20,000 objects obtained by combining flux-limited Sloan Digital Sky Survey optical and Wide field Infrared Survey Explorer mid-infrared data. We apply methods developed in previous works to access the intrinsic population distributions non-parametrically, taking into account the truncations and correlations inherent in the data. We find that the population of quasars exhibits positive luminosity evolution with redshift in the mid-infrared, but with considerably less mid-infrared evolution than in the optical or radio bands. With the luminosity evolutions accounted for, we determine …

The Braking Index Of A Radio-Quiet Gamma-Ray Pulsar, C. J. Clark, H. J. Pletsch, J. Wu, L. Guillemot, F. Camilo, T. J. Johnson, M. Kerr, B. Allen, C. Aulbert, C. Beer, O. Bock, A. Cuellar, H. B. Eggenstein, H. Fehrmann, M. Kramer, B. Machenschalk, L. Nieder

Physics and Astronomy Faculty Publications and Presentations

We report the discovery and timing measurements of PSR J1208−6238, a young and highly magnetized gamma-ray pulsar, with a spin period of 440 ms. The pulsar was discovered in gamma-ray photon data from the Fermi Large Area Telescope (LAT) during a blind-search survey of unidentified LAT sources, running on the distributed volunteer computing system Einstein@Home. No radio pulsations were detected in dedicated follow-up searches with the Parkes radio telescope, with a flux density upper limit at 1369 MHz of 30 μJy. By timing this pulsar's gamma-ray pulsations, we measure its braking index over five years of LAT observations …

Siuc Dark Site Observatory, Teresa M. Meyer Ms.

ASA Multidisciplinary Research Symposium

A joint venture between the SIUC Physics department, which houses the astronomy curriculum, and the Architecture department has begun the planning for the two upcoming total solar eclipses in 2017 and 2024.

The Intermediate-Line Region In Active Galactic Nuclei, T. P. Adhikari, A. Różańska, B. Czerny, K. Hryniewicz, Gary J. Ferland

Physics and Astronomy Faculty Publications

We show that the recently observed suppression of the gap between the broad-line region (BLR) and the narrow-line region (NLR) in some active galactic nuclei (AGNs) can be fully explained by an increase of the gas density in the emitting region. Our model predicts the formation of the intermediate-line region (ILR) that is observed in some Seyfert galaxies by the detection of emission lines with intermediate-velocity FWHM ~ 700–1200 km s⁻¹. These lines are believed to be originating from an ILR located somewhere between the BLR and NLR. As was previously proved, the apparent gap is assumed to …

Improving The Efficiency Of Gravitational Wave Detection, Jessica Page, Tyson Littenberg

Von Braun Symposium Student Posters

No abstract provided.

Enhancing The Science Return Of Lunar Surface Studies: Analysis Of Rediscovered Data From Apollo 17'S Lunar Seismic Profiling Experiment, Deanna Phillips, Richard Miller

Von Braun Symposium Student Posters

No abstract provided.

The Growth Of The Central Region By Acquisition Of Counterrotating Gas In Star-Forming Galaxies, Yan-Mei Chen, Yong Shi, Christy A. Tremonti, Matt Bershady, Michael Merrifield, Eric Emsellem, Yi-Fei Jin, Song Huang, Hai Fu, David A. Wake, Kevin Bundy, David Stark, Lihwai Lin, Maria Argudo-Fernandez, Thaisa Storchi Bergmann, Dmitry Bizyaev, Joel Brownstein, Martin Bureau, John Chisholm, Niv Drory, Qi Guo, Lei Hao, Jian Hu, Cheng Li, Ran Li, Alexandre Roman Lopes, Kai-Ke Pan, Rogemar A Riffel, Daniel Thomas, Lan Wang, Renbin Yan

Physics and Astronomy Faculty Publications

Galaxies grow through both internal and external processes. In about 10% of nearby red galaxies with little star formation, gas and stars are counter-rotating, demonstrating the importance of external gas acquisition in these galaxies. However, systematic studies of such phenomena in blue, star-forming galaxies are rare, leaving uncertain the role of external gas acquisition in driving evolution of blue galaxies. Here, based on new measurements with integral field spectroscopy of a large representative galaxy sample, we find an appreciable fraction of counter-rotators among blue galaxies (9 out of 489 galaxies). The central regions of blue counter-rotators show younger stellar populations …

Fluctuations In A Cosmology With A Spacelike Singularity And Their Gauge Theory Dual Description, Robert H. Brandenberger, Elisa G. M. Ferreira, Ian A. Morrison, Yi-Fu Cai, Sumit R. Das, Yi Wang

Physics and Astronomy Faculty Publications

We consider a time-dependent deformation of anti–de Sitter (AdS) space-time which contains a spacelike “singularity”—a spacelike region of high curvature. Making use of the AdS/CFT correspondence we can map the bulk dynamics onto the boundary. The boundary theory has a time dependent coupling constant which becomes small at times when the bulk space-time is highly curved. We investigate the propagation of small fluctuations of a test scalar field from early times before the bulk singularity to late times after the singularity. Under the assumption that the AdS/CFT correspondence extends to deformed AdS space-times, we can map the bulk evolution of …

Large Linear Magnetoresistance In Heavily-Doped Nb:Srtio3 Epitaxial Thin Films, Hyunwoo Jin, Keundong Lee, Seung-Hyub Baek, Jin-Sang Kim, Byung-Ki Cheong, Bae Ho Park, Sungwon Yoon, B. J. Suh, Changyoung Kim, Sung S. Ambrose Seo, Suyoun Lee

Physics and Astronomy Faculty Publications

Interaction between electrons has long been a focused topic in condensed-matter physics since it has led to the discoveries of astonishing phenomena, for example, high-T_c superconductivity and colossal magnetoresistance (CMR) in strongly-correlated materials. In the study of strongly-correlated perovskite oxides, Nb-doped SrTiO₃ (Nb:SrTiO₃) has been a workhorse not only as a conducting substrate, but also as a host possessing high carrier mobility. In this work, we report the observations of large linear magnetoresistance (LMR) and the metal-to-insulator transition (MIT) induced by magnetic field in heavily-doped Nb:STO (SrNb_0.2Ti_0.8O₃) epitaxial thin …

Optimizing The Telescope Assembly Alignment Simulator For Sofia, Zoe E. Sharp, Alex Quyenvo, Jennifer Briggs, Brian Eney

STAR Program Research Presentations

The Stratospheric Observatory for Infrared Astronomy (SOFIA) conducts research on a modified Boeing 747sp aircraft. By using a variety of infrared science instruments mounted on a 2.7 meter telescope, researchers can make discoveries about the galactic center, star formation, and various topics associated with a deeper understanding of our universe. To efficiently collect data through the SOFIA instruments, the instruments must be tested and prepared prior to being placed on the aircraft. Therefore, with the use of the Telescope Assembly Alignment Simulator (TAAS), researchers can design and construct improvements needed for these instruments to efficiently perform while in flight. The …

The Abundance Discrepancy Factor And T2 In Nebulae: Are Non-Thermal Electrons The Culprits?, Gary J. Ferland, W. J. Henney, C. R. O'Dell, M. Peimbert

Physics and Astronomy Faculty Publications

We discuss recent claims that the free electrons in ionized nebulae may not have a significantly Maxwellian velocity distribution. Supra-thermal electrons, electrons with much more energy than is encountered at electron temperatures found in nebulae, may solve the t²/ADF puzzle, the observations that abundances obtained from recombination and collisionally excited lines do not agree, and that different temperature indicators give different results. These non-Maxwellian electrons can be designated by the kappa formalism. We show that the distance over which heating rates change are much longer than the distance supra-thermal electrons can travel, and that the timescale to thermalize …

Measurement And Modeling Of Cosmic Ray Exposure For Supercdms Dark Matter Detectors., Kameron Mccall, John Orrell, Jared Yamaoka

STAR Program Research Presentations

Dark matter is an unknown type of matter that composes roughly 27% of the observable universe and, as cosmological structure models suggest, the earth should be passing through a “dark halo” of this unknown matter present in the Milky Way galaxy. As we pass through this halo, the Super Cryogenic Dark Matter Search (SuperCDMS) experiment aims to directly detect dark -matter particles. Though many dark matter particle candidates exist, SuperCDMS focuses on the detection of particles called WIMPS (weakly interacting massive particles) as predicted by super-symmetric theories beyond the standard model. Due to the high-sensitivity of the germanium detectors employed, …

Physical Science Day: Design, Implementation, And Assessment, Liang Zeng, Mark A. Cunningham, Steven C. Tidrow, K. Christopher Smith, Jerry Contreras

Physics and Astronomy Faculty Publications and Presentations

Physical Science Day at The University of Texas–Pan American (UTPA), in collaboration with the Edinburg Consolidated Independent School District, has been designed, developed and implemented to address an identified fundamental shortcoming in our educational process within this primarily (90+%) Hispanic serving border region. Physical Science Day overcomes the lack of knowledge about what physics is by raising youth awareness of physics as the foundation of science, engineering and technology disciplines, through activities including hands-on laboratory experiments, career orientation, and higher educational student and graduated student testimonials. Thus, Physical Science Day encourages, attracts, and enables more Hispanic youth towards science, technology …

"Blinded By The Lines: Mid-Ir Spectra Of Mira Variables Taken With Spitzer", Dana Baylis-Aguirre, Michelle J. Creech-Eakman, Donald G. Luttermoser, Tina Gueth

ETSU Faculty Works

We present preliminary analysis of mid-infrared spectra of M-type and C-type Mira variables. Due to the brightness of this sample, it is straightforward to monitor changes with phase in the infrared spectral features of these regular pulsators. We have spectra of 25 Mira variables, taken with phase, using the Spitzer Infrared Spectrograph (IRS) high-resolution module. Each star has multiple spectra obtained over a one-year period from 2008-09. This is a rich, unique data set due to multiple observations of each star and the high signal-to-noise ratio from quick exposure times to prevent saturation of the IRS instrument. This paper focuses …

The Baryon Cycle At High Redshifts: Effects Of Galactic Winds On Galaxy Evolution In Overdense And Average Regions, Raphael Sadoun, Isaac Shlosman, Jun-Hwan Choi, Emilio Romano-Díaz

Physics and Astronomy Faculty Publications

We employ high-resolution cosmological zoom-in simulations focusing on a high-sigma peak and an average cosmological field at z ~ 6–12 in order to investigate the influence of environment and baryonic feedback on galaxy evolution in the reionization epoch. Strong feedback, e.g., galactic winds, caused by elevated star formation rates (SFRs) is expected to play an important role in this evolution. We compare different outflow prescriptions: (i) constant wind velocity (CW), (ii) variable wind scaling with galaxy properties (VW), and (iii) no outflows (NW). The overdensity leads to accelerated evolution of dark matter and baryonic structures, absent from the "normal" region, …

High-Velocity Bipolar Molecular Emission From An Agn Torus, Jack F. Gallimore, Moshe Elitzur, Robert Maiolino, Alessandro Marconi, Christopher P. O'Dea, Dieter Lutz, Stefi A. Baum, Robert Nikutta, C. M. V. Impellizzeri, Richard Davies, Amy E. Kimball, Eleonora Sani

Physics and Astronomy Faculty Publications

We have detected in ALMA observations CO J = 6 → 5 emission from the nucleus of the Seyfert galaxy NGC 1068. The low-velocity (up to ±70 km s⁻¹ relative to systemic) CO emission resolves into a 12 × 7 pc structure, roughly aligned with the nuclear radio source. Higher-velocity emission (up to ±400 km s⁻¹) is consistent with a bipolar outflow in a direction nearly perpendicular (≃80°) to the nuclear disk. The position–velocity diagram shows that in addition to the outflow, the velocity field may also contain rotation about the disk axis. These observations provide compelling …