Session F2: Astronomy, Astrophysics and Space Sciences and Condensed Matter

Electromagnetic Properties of Extremely Hot and Dense Media of Superdense Systems

We study the properties of particles in extremely hot and dense media of superdense systems. Using the properties of vacuum polarization tensors in a medium, we study the properties of superdense systems. We use simple QED type calculations to start comparison of different approaches to choose the best out of them to be able to learn more about these systems. We show that the electromagnetic properties of the medium such as electric permittivity, magnetic permeability and the refractive index of the medium become function of statistical parameters such as temperature and density of the medium. However, we can rule out certain combination of temperature and density regions for physical systems.   

Primordial Gravitational Wave Calculations: Nonlinear vs Linear Codes

This work is a follow-up to the paper, ``Numerical Relativity as a Tool for Studying the Early Universe.'' Here, I present the first results of direct numerical simulations of primordial plasma turbulence as it applies to the generation of gravitational waves. I calculate the normalized energy density, strain and degree of polarization of gravitational waves produced by a simulated turbulent plasma similar to what was believed to have existed at the electroweak scale, 246 GeV. This calculation is completed using two numerical codes, one which utilizes full General Relativity calculations based on modified BSSN equations while the other utilizes a linearized approximation of General Relativity. The results show that there is a significant difference between the spectrum of gravitational waves calculated using a nonlinear code as opposed to that calculated with a linear approximation. This implies that simulations that do not take into account nonlinear effects may not give accurate results.   

Observations and Analysis of the New Dwarf Nova ASASSN-14cv

On June 21, 2014 a new bright cataclysmic variable star, ASASSN-14cv, was detected in the constellation Draco by the All-Sky Automated Survey for Supernovae, ASAS-SN. The 13$^{\mathrm{th}}$ magnitude CV matches to a blue 19$^{\mathrm{th}}$ magnitude SDSS star, but no previous outburst data is to be found in CRTS data. During follow-up observations performed using the University of North Texas' Monroe Robotic Observatory, the CV was observed over the course of ten nights for a total of 495 images from its early plateau stage until quiescence. Ensemble photometry performed on the raw images was used to produce light curves for the CV which were then analyzed in order to determine an early superhump period of 0.0592 d. During quiescence the orbital period was measured to be 0.0609 d. Early outburst data is rare and few observers go on to perform careful analysis of such data, making these results of particular interest in studying CVs.   

Discovery and Follow-up Observations of the Exoplanet Candidate GSC02087-01126

Wide angle survey measurements by the University of Dallas Small Telescope Extrasolar Transit Survey (STExTS) in the summer of 2012 found that the star GSC02087-01126 exhibits characteristics of a possible transit. According to the UCAC4 catalogue, the star has a (B-V)$_{\mathrm{o}}$ magnitude of 0.265, corresponding to a temperature of 7402 K, which is a reasonable for a star in possession of a planet. Using the box least squares (BLS) function, we determined a likely period for the orbit of 0.79380 days. Calculation of the ephemeris led to taking follow up data targeted toward the specific dates of the transit in the summer of 2014 with additional follow-up measurements in the spring of 2015 using the University of North Texas' Monroe Robotic Observatory. The observational data and calculated quantities will be presented.   

Molecular Coupling of Formaldehyde on Rutile TiO$_2$(110)

Molecular coupling of formaldehyde is imaged by variable temperature scanning tunneling microscope (VT-STM) on Rutile TiO$_{2}$(110) surfaces in our study. Two different molecular coupling reactions are identified via time-elapsed sequences of STM images. A formaldehyde bounded at a bridging oxygen vacancy site (V$_{\mathrm{O}}$-bound CH$_{2}$O) couples with Ti-bound CH$_{2}$O to form a static and stable diolate at room temperature and low temperatures. Also, two V$_{\mathrm{O}}$-bound CH$_{2}$O molecules couple with each other to form a Ti-bound species and desorb above 215 K. This coupling reaction heals both the V$_{\mathrm{O}}$ sites indicating formation and desorption of ethylene. In addition, we directly observe the diffusion of methylene groups to nearby empty V$_{\mathrm{O}}$ sites formed upon dissociation of the C-O bond in V$_{\mathrm{O}}$-bound formaldehyde, which suggests that the ethylene formation is via coupling of the methylene groups. These results will be discussed with previously reported chemistry of formaldehyde on TiO$_{2}$ surface.   

F Center Formation in Sapphire Under Low Dose Low Energy Ar Irradiation

Optical spectroscopy and Rutherford Backscattering Spectrometry Channeling (RBS-C) have been used to study F center dynamics in 170 keV Ar$^+$ irradiated single crystals of sapphire ($\alpha$-Al$_2$O$_3$) at room temperature for implantation doses between $10^{13}$ Ar$^+$ cm$^{-2}$ to $5\times 10^{14}$ Ar$^+$ cm$^{-2}$ . F center density (N$_{\mathrm{F}}$) has been found to display an initial rapid linear increase with Ar$^+$ dose and then saturate to a maximum value of $4.02 \times 10^{14}$ cm$^{-3}$. Fitting experimental results with a Poisson relation suggest an estimated electron capture range of $4.24\times 10^{-10}$ m around an Oxygen vacancy. A possible explanation to this behaviour is presented.   

Exploring optimization strategies for the SuperCDMS experiment

The Cryogenic Dark Matter Search (SuperCDMS) experiment uses a number of low temperature detectors deep underground to search for dark matter. Since there are many ways to analyze the data, we have studied the potential impact of several optimization techniques with the hopes of improving the overall sensitivity. Each emphasizes the differing background expectations and signal acceptances among the detectors considered, as well optimizing for the experiment as a whole. We present preliminary results on our studies.