Astrophysics and Astronomy Commons^™

Ri/Mom And Ri/Smom Renormalization Of Overlap Quark Bilinears On Domain Wall Fermion Configurations, Yujiang Bi, Hao Cai, Ying Chen, Ming Gong, Keh-Fei Liu, Zhaofeng Liu, Yi-Bo Yang

Physics and Astronomy Faculty Publications

Renormalization constants (RCs) of overlap quark bilinear operators on 2+1-flavor domain wall fermion configurations are calculated by using the RI/MOM and RI/SMOM schemes. The scale independent RC for the axial vector current is computed by using a Ward identity. Then the RCs for the quark field and the vector, tensor, scalar, and pseudoscalar operators are calculated in both the RI/MOM and RI/SMOM schemes. The RCs are converted to the MS¯ scheme and we compare the numerical results from using the two intermediate schemes. The lattice size is 48³ × 96 and the inverse spacing 1/a = 1.730(4)  GeV.

A Study On The Extrasolar Transits Of Wasp-89b, Wasp-32b, And Hat-P-23b, Conner Kelley

Honors Theses

No abstract provided.

Hard Exclusive Pion Electroproduction At Backward Angles With Clas, K. Park, M. Guidal, R. W. Gothe, B. Pire, G. Charles, C. E. Hyde, S E. Kuhn, J. Poudel, Y. Prok

Physics Faculty Publications

We report on the first measurement of cross sections for exclusive deeply virtual pion electroproduction off the proton, ep → e'nπ⁺, above the resonance region at backward pion center-of-mass angles. The ϕ∗ π-dependent cross sections were measured, from which we extracted three combinations of structure functions of the proton. Our results are compatible with calculations based on nucleon-to-pion transition distribution amplitudes (TDAs). These non-perturbative objects are defined as matrix elements of threequark-light-cone-operators and characterize partonic correlations with a particular emphasis on baryon charge distribution inside a nucleon.

Comparing Three Pulsating Subdwarf B Stars Observed By Kepler In The Open Cluster Ngc 6791, Joshua William Kern

Graduate Theses/Dissertations

Using their entire Kepler data sets, I performed asteroseismic analyses and comparisons of three gravity (g-) mode pulsating subdwarf B (sdB) stars in the open cluster NGC 6791. I constructed light curves with a combination of long and short cadence data to span quarters 1 (Q01) through Q17 of KIC 2569576 (B3), KIC 2438324 (B4), and KIC 2437937 (B5). Rotationally induced g-mode frequency splittings were observed in each star allowing us to calculate rotation periods of 64.5 ± 8.2, 9.21 ± 0.18, and 91.3 ± 14.1 days for B3, B4, and B5, respectively. Using the observed ratio of the azimuthal …

Single And Multiparameter Estimation Using Multimode Interferometry And Single Photons, Margarite L. Laborde

Honors Capstones

No abstract provided.

Galaxy And Mass Assembly (Gama): Morphological Transformation Of Galaxies Across The Green Valley, M. N. Bremer, S. Phillipps, S. Kelvin, R. De Propris, Rebecca Kennedy, Amanda J. Moffett, S. Bamford, L. J.M. Davies, S. P. Driver, B. Häußler, Benne W. Holwerda, A. Hopkins, P. A. James, J. Liske, S. Percival, N. Taylor

Faculty and Staff Scholarship

We explore constraints on the joint photometric and morphological evolution of typical low redshift galaxies as they move from the blue cloud through the green valley and on to the red sequence. We select Galaxy And Mass Assembly (GAMA) survey galaxies with 10.25 < log(M*/Mo˙) < 10.75 and z < 0.2 classified according to their intrinsic u* - r* colour. From single component Śersic fits, we find that the stellar mass-sensitive K-band profiles of red and green galaxy populations are very similar while g-band profiles indicate more disc-like morphologies for the green galaxies: apparent (optical) morphological differences arise primarily from radial mass-to-light ratio variations. Two-component fits show that most green galaxies have significant bulge and disc components and that the blue to red evolution is driven by colour change in the disc. Together, these strongly suggest that galaxies evolve from blue to red through secular disc fading and that a strong bulge is present prior to any decline in star formation. The relative abundance of the green population implies a typical time-scale for traversing the green valley ~1-2 Gyr and is independent of environment, unlike that of the red and blue populations. While environment likely plays a role in triggering the passage across the green valley, it appears to have little effect on time taken. These results are consistent with a green valley population dominated by (early type) disc galaxies that are insufficiently supplied with gas to maintain previous levels of disc star formation, eventually attaining passive colours. No single event is needed to quench their star formation.

An Investigation Into The Suitability Of Sulfate-Reducing Bacteria As Models For Martian Forward Contamination, Maxwell M. W. Silver

Graduate Theses and Dissertations

The NASA Planetary Protection policy requires interplanetary space missions do not compromise the target body for a current or future scientific investigation and do not pose an unacceptable risk to Earth, including biologic materials. Robotic missions to Mars pose a risk to planetary protection in the forms of forward and reverse contamination. To reduce these risks, a firm understanding of microbial response to Mars conditions is required. Sulfate-reducing bacteria are prime candidates for potential forward contamination on Mars. Understanding the potential for forward-contamination of sulfate-reducers on Mars calls for the characterization of sulfate-reducers under Mars atmosphere, temperature, and sulfate-brines. This …

The Role Of Co2 Sublimation In Mass Wasting And Landscape Evolution Under Martian Conditions, Matthew Edwin Sylvest

Graduate Theses and Dissertations

Here we present the first set of laboratory experiments under martian atmospheric conditions which demonstrate that the sublimation of CO2 ice from within the sediment body can trigger failure of unconsolidated, regolith slopes, and can measurably alter the landscape. Previous theoretical studies required CO2 slab ice for movements, but we find that only frost is required. Hence, sediment transport by CO2 sublimation could be more widely applicable (in space and time) on Mars than previously thought. This supports recent work suggesting CO2 sublimation could be responsible for recent modification in martian gullies.

A second set of experiments were carried out …

Novel Nonlinear And Quantum Devices Based On Multimode Optical Fibers, Hamed Pourbeyram

Physics & Astronomy ETDs

In this dissertation, multimode optical fibers (MMFs) have been studied as a robust and practical platform for nonlinear optics and quantum optics applications, where by experimental investigations and theoretical calculations we present the quantum and nonlinear virtue of MMFs as a versatile tool for future applications. Our investigations can be summarized in three parts: At first, we have investigated stimulated Raman scattering (SRS) in a long MMF, where more than 20 orders of cascaded Raman peaks have been generated. Observation of beam clean-up despite the highly multimode nature of the fiber and such strong nonlinear interaction despite the large fiber …

Automated Software For The Detection Of Bolide Events, Elena Botella

Theses and Dissertations

The proper detection and analysis of bolide events ensures that we will once day be prepared for a big, catastrophic impact by a meteor. The data obtained from the analysis of these detected smaller events will provide important information about the meteor’s journey through our atmosphere and its orbit before it crossed the Earth’s path. SkySentinel is one of the All-Sky networks in charge of looking at the skies every night and detecting these objects as they fall. At the moment, SkySentinel’s detection process relies heavily on manpower to check whether their cameras picked up actual bolide events or false …

The Stellar Populations Of Two Ultra-Diffuse Galaxies From Optical And Near-Infrared Photometry, Viraj Pandya, Aaron J. Romanowsky, Seppo Laine, Jean Brodie, Benjamin Johnson, William Glaccum, Alexa Villaume, Jean-Charles Cuillandre, Stephen Gwyn, Jessica Krick, Ronald Lasker, Ignacio Martín-Navarro, David Martinez-Delgado, Pieter Van Dokkum

Faculty Publications

We present observational constraints on the stellar populations of two ultra-diffuse galaxies (UDGs) using optical through near-infrared (NIR) spectral energy distribution (SED) fitting. Our analysis is enabled by new Spitzer-IRAC 3.6 and 4.5 μm imaging, archival optical imaging, and the prospectorfully Bayesian SED fitting framework. Our sample contains one field UDG (DGSAT I), one Virgo cluster UDG (VCC 1287), and one Virgo cluster dwarf elliptical for comparison (VCC 1122). We find that the optical–NIR colors of the three galaxies are significantly different from each other. We infer that VCC 1287 has an old (7.7 Gyr) and surprisingly metal-poor …

Upper Limits On The Presence Of Central Massive Black Holes In Two Ultra-Compact Dwarf Galaxies In Centaurus A, Karina Voggel, Anil Seth, Nadine Neumayer, Steffen Mieske, Igor Chilingarian, Christopher Ahn, Holger Baumgardt, Michael Hilker, Dieu Nguyen, Aaron J. Romanowsky, Jonelle Walsh, Mark Den Brok, Jay Strader

Faculty Publications

The recent discovery of massive black holes (BHs) in the centers of high-mass ultra-compact dwarf galaxies (UCDs) suggests that at least some are the stripped nuclear star clusters of dwarf galaxies. We present the first study that investigates whether such massive BHs, and therefore stripped nuclei, also exist in low-mass (M < 107 M ⊙) UCDs. We constrain the BH masses of two UCDs located in Centaurus A (UCD 320 and UCD 330) using Jeans modeling of the resolved stellar kinematics from adaptive optics data obtained with the SINFONI integral field spectrograph at the Very Large Telescope (VLT/SINFONI). No massive BHs …

Seeing An Exoplanet, Leo Moraczewski

Celebrating Scholarship and Creativity Day (2018-)

In my experiment, I used the telescopes at the Saint John’s Observatory to measure the brightness of three stars that were expected to have exoplanets orbiting them. I was unable to take enough data on two of the stars, but was able to confirm the existence of an exoplanet around the third, HD189733.

Lunar Ice Cube: Development Of A Numerical Model For Attitude Control, Alexander Roberts, Benjamin Malphrus, Kevin Brown

Celebration of Student Scholarship Poster Sessions Archive

No abstract provided.

Msu And Citizen Cate: A High Definition Look At The Sun’S Inner Corona During The 2017 Solar Eclipse Over Hopkinsville, Kentucky., Jessie Anderson, Ethan Caudill

Celebration of Student Scholarship Poster Sessions Archive

No abstract provided.

Primordial Black Hole Atoms, David Zwick, Tyler Hanover, Brian Nepper

STEM Student Research Symposium Posters

Primordial black holes are thought to have been formed at the early stages of the universe in the presence of non-homogeneous density distributions of dark matter. We are working under the assumption that dark matter consists of elementary low mass particles, specifically, spin 1/2 fermions. We further assume that dark matter is electrically neutral, thus its main interaction is gravitational. We investigate dark matter spin 1/2 fermions in orbit around a black hole atom and consider mass ranges for which the quantum description is appropriate. Solutions to the Dirac equation are utilized to describe the radial mass distribution of primordial …

Illuminating Low Surface Brightness Galaxies With The Hyper Suprime-Cam Survey, Johnny P. Greco, Jenny E. Greene, Michael A. Strauss, Lauren A. Macarthur, Xzavier Flowers, Andy D. Goulding, Song Huang, Ji Hoon Kim, Yutaka Komiyama, Alexie Leauthaud, Lukas Leisman, Robert H. Lupton, Cristobal Sifon, Shiang-Yu Wang

Aerospace, Physics, and Space Science Faculty Publications

We present a catalog of extended low surface brightness galaxies (LSBGs) identified in the Wide layer of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). Using the first ∼200 deg2 of the survey, we have uncovered 781 LSBGs, spanning red (g − I >/0.64) and blue (g − i < 0.64) colors and a wide range of morphologies. Since we focus on extended galaxies (reff = 2 5–14″), our sample is likely dominated by low- redshift objects. We define LSBGs to have mean surface brightnesses m¯ eff (g) > 24.3 mag arcsec−2, which allows nucleated galaxies into our sample. As a result, the central surface brightness distribution spans a wide range of μ0(g) = 18–27.4 mag arcsec−2, with 50% and 95% of galaxies fainter than 24.3 and 22 mag arcsec−2, respectively. Furthermore, the surface brightness distribution is a strong function of …

The Green Bank Northern Celestial Cap Pulsar Survey. Ii. The Discovery And Timing Of 10 Pulsars, A. M. Kawash, M. A. Mclaughlin, Louis Percy Dartez, David Day, Anthony J. Ford, Jesus Hinojosa, Fredrick A. Jenet, Sean Leake, Grady Lunsford, Alberto Mata

Physics & Astronomy Faculty Publications

We present timing solutions for 10 pulsars discovered in 350 MHz searches with the Green Bank Telescope. Nine of these were discovered in the Green Bank Northern Celestial Cap survey and one was discovered by students in the Pulsar Search Collaboratory program during an analysis of drift-scan data. Following the discovery and confirmation with the Green Bank Telescope, timing has yielded phase-connected solutions with high-precision measurements of rotational and astrometric parameters. Eight of the pulsars are slow and isolated, including PSR J0930-2301, a pulsar with a nulling fraction lower limit of ∼30% and a nulling timescale of seconds to minutes. …

Does The Black Hole Shadow Probe The Event Horizon Geometry?, Pedro V. P. Cunha, Carlos A. R. Herdeiro, Maria J. Rodriguez

All Physics Faculty Publications

There is an exciting prospect of obtaining the shadow of astrophysical black holes (BHs) in the near future with the Event Horizon Telescope. As a matter of principle, this justifies asking how much one can learn about the BH horizon itself from such a measurement. Since the shadow is determined by a set of special photon orbits, rather than horizon properties, it is possible that different horizon geometries yield similar shadows. One may then ask how sensitive is the shadow to details of the horizon geometry? As a case study, we consider the double Schwarzschild BH and analyze the impact …

Infrared Properties Of Stars In The Bulge Asymmetries And Dynamical Evolution Survey, Eddie Hilburn

Physics & Astronomy ETDs

The Bulge Asymmetries and Dynamical Evolution (BAaDE) survey is an SiO maser survey of 28,062 infrared-selected evolved stars primarily in the Galactic plane. By cross-matching the BAaDE target sources with nine different infrared catalogs, we have constructed a catalog with wavelength coverage from 0.71 to 80 m. Using this catalog, we fit the data for each source to a model spectral energy distribution (SED) generated with the radiation transport program DUSTY in order to obtain characteristics such as bolometric flux, source effective temperature, and the optical depth of the circumstellar envelope.

The overall goal of the BAaDE survey is to …