Physics and Astronomy REU 2017

May 30 - July 29

 

 

 

Projects

 

“ Radiative Transport in Type 1a Supernovae ”

Christopher Cain - Azusa Pacific University
Mentor: Dr. Eddie Baron


Supernovae (plural of supernova) form when stars, most commonly either White Dwarfs or Red Giants, explode. These events can take months to fully transpire, and during that time information about the explosion can be gained from the observed optical electromagnetic power spectra of the supernova. Spectral lines form for various elements with characteristics that depend on certain physical parameters, such as the optical depth (thickness) of the elements, and their velocity. Specically, the distribution of velocities of elements in the ejecta of a supernova (termed "abundance stratication") is of particular interest to theorists. We will be using the supernova simulation code SYNOW (SYnthetic NOW) to match simulated spectra with known specified parameters to observed spectra of the supernova classified SN2012fr. After obtaining rough fits, we will move to more advanced software for more accurate estimates. Our goal will be to understand how the velocity and distribution of various elements in the ejecta of SN2012fr, particularly Silicon, change with time.

5 minute talk


15 minute talk

“Simulated IR Spectrum of Alkanethiol SAM on Au(111) ”

Antonius Ghanim - Whitworth University

Mentor: Dr. Lloyd Bumm


The results from the STM produced images showed that the alkanethiol SAMs have a 4-molecule basis structure. This motivated the group to build a model that could explain the results. A model was built using molecular dynamics which gave insight to what might be happening under the surface of the layer and so far, it agrees with what we observe on the surface. Another experimental result is the IR spectrum of the monolayer which we are using to compare our simulated IR spectrum from the model with.

5 minute talk


15 minute talk

“ Lagurerre-Gaussian Beam Mode Purity ”

Nia Burrell - Lafayette College
Mentor: Dr. Eric Abraham

I am working with Dr. Eric Abraham on experimental atomic, molecular, and optical physics. I will be using electromagnetic radiation and diffractive optics to generate different modes of Laguerre-Gaussian beams. The data that I collect is obtained from images of these beams at different propagation distances. I utilize Python to calculate power of the beams as a function of propagation distance. I will be able to analyze these values to produce the best profiles of the beams and maximize their purity, where intensity is proportional to the Laguerre polynomial.

5 minute talk


15 minute talk

“ HALT/HASS Testing of ATLAS Pixel Detector Modules ”

Jessica Johnson - Hastings College
Mentor: Dr. John Stupak

The ATLAS detector is one of two main particle detectors in the Large Hadron Collider (LHC). The detector's inner most detection area, the pixel detector, is about to be upgraded. The pixel detector modules that are to be used in the upgrade need to be tested before being put in the detector. Using HALT/ HASS testing the modules will undergo thermal and vibration stresses that will simulate the stresses they will encounter in their lifetime in the detector. The purpose of this is to design a testing station to determine if there are any defects in the modules before they are put into the detector. This project will specifically look at the design and testing of the cooling platform of the testing station.

5 minute talk


15 minute talk

“ Stabilizing Laser and Microwave Fields for Coherent Control of Spin-Exchange Collisions in Ultracold Sodium Gases ”

Jeremy Norris- University of Southern Mississippi
Mentor: Dr. Arne Schwettmann

Spin-exchange collisions in ultracold sodium gases create quantum entanglement between atoms with spin up and spin down. This opens the door for experiments on matter-wave quantum optics in spin space, similar to what has been done with entangled beams of light. One example is quantum enhanced interferometry. To implement such experiments, cooling of the gas and precise control over the collisions are necessary. In sodium, this can be done with near-resonance laser fields at ~589 nm and microwaves at 1.8 GHz. In my project, I will implement methods to stabilize and control the amplitude and frequency of those fields using active feedback loops and computer controlled direct digital synthesis.

5 minute talk


15 minute talk

“ Title: Rotating Periods of Asteroids ”

Jordan Van Nest- Trevecca Nazarene University
Mentor: Dr. Mukremin Kilic

This presentation is on detecting the rotation periods of asteroids. Eight nights of observation were analyzed with image subtraction in order to locate asteroids in the night sky. By tracking the positions of these asteroids, the software that is responsible for the image subtraction can also give a measurement of the asteroids optical magnitude. The light curve of an asteroid is obtained by plotting the magnitudes of the asteroid throughout the night. Since the asteroid is an assumably non-spherical object rotating periodically, the light curve should have some periodic properties. A Fourier analysis of the light curve should define a clear rotation period for an asteroid.

5 minute talk


15 minute talk

“ Population of the Oort Cloud ”

Katherine Shepard- Sarah Lawrence College
Mentor: Dr. Nate Kaib

The Oort Cloud is a theoretical sphere of icy cometary bodies that surrounds our solar system. It was formed during the early years of the solar system as a result of the formation and gravitational influences of the four giant planets. Simulations however, do not yield the expected population. Standard models of the Oort Cloud formation suggest that the population should be approximately 10 - 100 times greater than what the simulations are showing. A possible solution to this discrepancy is the incorporation of an Ultra-Wide binary star system during the early years of the solar system. The presence of the binary star would aid in the capture and scattering of cometary bodies before the system was destroyed. We are currently simulating the control system, which omits the binary star. Future simulations will include the binary star and will hopefully result in an increase in Oort Cloud population that will match the models.

5 minute talk


15 minute talk

“ Properties of Void Galaxies ”

Sean Bruton- University of Oklahoma
Mentor: Dr. Xinyu Dai

Void galaxies are galaxies which occupy under-dense regions of the universe, called voids. This allows them to evolve with few neighboring gravitational interactions, giving us a glimpse at galaxy formation through the collapse of gas clouds. They have different properties from galaxies in clusters, most of which are derived from their higher stellar formation rate. However, they also have some properties which are similar to cluster galaxies, such as their percentage of active galactic nuclei (AGN). This can constrain models regarding how AGN become triggered. Thus, further study of void galaxies may reveal information about galaxy formation, AGN, and cosmological parameters. To this end, we are constructing a catalog of void galaxies from the Sloan Digital Sky Survey and WiggleZ Dark Energy Survey spectroscopic data for analysis.

5 minute talk


15 minute talk

“ Vector-like leptons ”

Miranda Brugman- University of Oklahoma
Mentor: Dr. Brad Abbott

The Large Hadron Collider collects an immense amount of data on sub-atomic collisions of protons. The standard model for particle physics describes the behaviors of known particles. The group I am working with is searching for theoretical particles in data from the LHC that are not described by the standard model. I am helping to build code that searches for signature decays of such particles in hopes of verifying or finding modifications for the standard model.

5 minute talk


15 minute talk

“ Influence of Stellar Companions on Fomalhaut's Ring ”

Ethan White- University of Oklahoma
Mentor: Dr. Nate Kaib

About 50% of all stars are thought to exist in binary star systems. For this reason it is important to understand how binary stars effect one another and their solar systems. Our project seeks to determine the cause of Fomalhaut's ring's eccentricity. We propose that the orbit of Fomalhaut's binary companion passed close enough to Fomalhaut's ring to cause the observed eccentricity without completely destroying it. To do this, we have run several simulations with varying conditions and are now in the process of analyzing these results to determine if our hypothesis is plausible.

5 minute talk


15 minute talk

“ Dilute Nitride (GaInNAs) Solar cells ”

Hannah Harrell- University of Oklahoma
Mentor: Dr. Ian Sellers

While multi-junction solar cells collect a wider range of wavelengths making them more efficient, the introduction of new materials often leads to alloy fluctuations, impurities, and other defects within the sample decreasing overall efficiency. Hydrogen and rapid thermal annealing (RTA) have been known to help pacify these defects. We have been using various methods to analyze the effects of passivation throughout the samples including temperature and power dependent photoluminescence (PL). We will continue to analyze these samples with electroluminescence (EL) which will allow us to compare radiative and no radiative procedures happening within the sample and external quantum efficiency (EQE) measurements which will allow us to determine where defects are forming within the sample.

5 minute talk


15 minute talk

“ Laser Spectroscopy of C02 ”

Christopher Leonard- University of Oklahoma
Mentor: Dr. Jim Shaffer

For this experiment, laser spectroscopy of a carbon dioxide gas sample is used to characterize the behavior of a quantum cascade laser in the range of 4320-4350 nm wavelengths. Frequency of the laser will be measured by varying input conditions and observing their relationship to the absorption spectrum of carbon dioxide, and power will be measured by a photodetector. The goal of this setup is to calibrate the laser for use in exciting individual electrons confined to the surface of a dielectric for potential use in quantum computing.

5 minute talk


15 minute talk

“ Protostars in the Orion Molecular Cloud Complex ”

Lisa Patel- University of Oklahoma
Mentor: Dr. John Tobin

Stars from inside relatively dense and huge complexes of interstellar gas and dust called molecular clouds, which are composed mostly of molecular hydrogen and have a temperature ranging from 10-50 K. Class 0 phase, the earliest recognizable phase of star formation, is characterized by the formation of a hydrostatically supported protostar within an infalling envelope of gas and dust. Typically, the next phase, Class I protostars, will have weaker envelopes. Identifying and studying these youngest sources is crucial for making statistical inferences of properties such as lifetimes, evolutionary class and luminosity evolution as well as answering unknown questions about the origin of multiplicity and properties of stellar disks. Using the sensitivity and resolution power of ALMA, the largest and most complete survey of 331 protostars in the Orion A and B at 0.09 degree resolution was conducted to enable a statistical analysis of disk properties and multiplicity. Currently, we are in the data processing stage of the 331 sources which includes calibration of the raw data and imaging using a package software called CASA.

5 minute talk


15 minute talk

“ Quantifying Quasar Outflows ”

Collin Dabbieri- University of Oklahoma
Mentor: Dr. Karen Leighly

A quasar is a system built around a supermassive black hole consisting of, among other things,a thin, hot accretion disk with high thermal luminosity. This disk expels winds of gas and dust throughout the host galaxy, and when radiation from the accretion disk is emitted, it can be partially absorbed by these windy outflows. By analyzing quasar spectra and fitting its absorption lines one is able to gain information about the physical conditions of the quasar outflows. We use a fitting method known as Emcee to fit the absorption and continuum profile for 26 quasar spectra and deterimine physical conditions of their host quasars.

5 minute talk


15 minute talk

“ Indium Arsenide (InAs) Quantum Dots for Applications in Intermediate Band Solar Cells (IBSC) ”

Tristan Thrasher- University of Oklahoma
Mentor: Dr. Ian Sellers

Photo-luminescence is utilized to observe self assembled Indium Arsenide Quantum Dot Structures. Manipulation of the system using a Gallium Arsenide (GaAs) -Antomony (Sb) matrix reduces the effective band gap and allows for a more qualitative spectral overlap and favorable conversion of the solar spectrum. Temperature Dependent External Quantum Efficiency measurements show an improvement in the QD regions with increasing temperature.

5 minute talk


15 minute talk

“ Zinc Oxide and its Photovoltaic Properties for its use in Solar Cells ”

Jill Kozlowski- University of Oklahoma
Mentor: Dr. Ian Sellers

The purpose of this research is to study zinc oxide (ZnO) and zinc oxide with cobalt (Co) as semiconductors to be used in solar cells. Thus far, this research has collected data on annealed ZnO as a reference for ZnOCo. The ZnO samples were each put in the rapid thermal annealer at different temperatures before having temperature dependent studies performed on them. In studying the photovoltaic properties of the samples, a laser was aimed at each sample and the relationship between intensity and wavelength of the output light was measured. This relationship combined with temperature dependent measurements gives information regarding the band gap of the zinc oxide and therefore its overall photovoltaic properties and potential use in solar cells.

5 minute talk


15 minute talk

“ Identifying White Dwarf Candidates ”

Courtney Crawford- University of Oklahoma
Mentor: Dr. Mukremin Kilic

abstract:I identify white dwarf candidates by cross matching targets with significant (5 sigma) proper motion in the HSOY catalog to photometric data from SDSS, using that data to create a proper motion diagram to identify objects kinematically grouped with white dwarfs, and then fitting the optical data with white dwarf atmospheric models to estimate temperature and composition of each object. I have a specific interest in identifying ultra cool hydrogen based white dwarfs.

5 minute talk


15 minute talk

 

 

 

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