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Articles 571 - 600 of 9201

Full-Text Articles in Physical Sciences and Mathematics

Nuclear Effects In The Deuteron And Global Qcd Analyses, S. I. Alekhin, S. A. Kulagin, Roberto Petti Jun 2022

Nuclear Effects In The Deuteron And Global Qcd Analyses, S. I. Alekhin, S. A. Kulagin, Roberto Petti

Faculty Publications

We report the results of a new global QCD analysis, which includes deep-inelastic 𝑒/𝜇 scattering data off proton and deuterium, as well as Drell-Yan lepton pair production in proton-proton and proton-deuterium collisions and 𝑊±/𝑍 boson production data from 𝑝⁢𝑝 and 𝑝⁢¯𝑝 collisions at the LHC and Tevatron. Nuclear effects in the deuteron are treated in terms of a nuclear convolution approach with bound off-shell nucleons within a weak binding approximation. The off-shell correction is controlled by a universal function of the Bjorken variable 𝑥, describing the modification of parton distributions in bound nucleons, which is determined in our …

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Complex Energies And The Lambert W Function, A Das, B.G. Sidharth, K. Roberts, Sree Ram Valluri Jun 2022

Complex Energies And The Lambert W Function, A Das, B.G. Sidharth, K. Roberts, Sree Ram Valluri

Physics and Astronomy Publications

We apply the Lambert W function in the context of complex energy values in statistical systems of fermions and bosons. We derive the condition for the transformation connecting fermions and bosons. We discuss the physical significance of these results and investigate the conditions under which bosonization effects take place. The fermion and boson statistical and structural distributions discussed in this work suggest the possibility of their extensions to generalized Planck distributions.

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Search For Multimessenger Signals In Nova Coincident With Ligo/Virgo Detections, M. A. Acero, P. Adamson, L. Aliaga, T. Alion, V. Alakhberdian, N. Anfimov, A. Antoshkin, L. Asquith, A. Aurisano, A. Back, C. Backhouse, M. Biard, N. Balashov, P. Baldi, B. A. Bambah, S. Bashar, K. Bays, S. Bending, R. Bernstein, V. Bhatnagar, Roberto Petti, Et. Al. Jun 2022

Search For Multimessenger Signals In Nova Coincident With Ligo/Virgo Detections, M. A. Acero, P. Adamson, L. Aliaga, T. Alion, V. Alakhberdian, N. Anfimov, A. Antoshkin, L. Asquith, A. Aurisano, A. Back, C. Backhouse, M. Biard, N. Balashov, P. Baldi, B. A. Bambah, S. Bashar, K. Bays, S. Bending, R. Bernstein, V. Bhatnagar, Roberto Petti, Et. Al.

Faculty Publications

Using the NOvA neutrino detectors, a broad search has been performed for any signal coincident with 28 gravitational wave events detected by the LIGO/Virgo Collaboration between September 2015 and July 2019. For all of these events, NOvA is sensitive to possible arrival of neutrinos and cosmic rays of GeV and higher energies. For five (seven) events in the NOvA Far (Near) Detector, timely public alerts from the LIGO/Virgo Collaboration allowed recording of MeV-scale events. No signal candidates were found.

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Narrowband Searches For Continuous And Long-Duration Transient Gravitational Waves From Known Pulsars In The Ligo-Virgo Third Observing Run, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang Jun 2022

Narrowband Searches For Continuous And Long-Duration Transient Gravitational Waves From Known Pulsars In The Ligo-Virgo Third Observing Run, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang

Physics and Astronomy Faculty Publications and Presentations

Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those …

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From Equal-Mass To Extreme-Mass-Ratio Binary Inspirals: Simulation Tools For Next Generation Gravitational Wave Detectors, Samuel Douglas Cupp Jun 2022

From Equal-Mass To Extreme-Mass-Ratio Binary Inspirals: Simulation Tools For Next Generation Gravitational Wave Detectors, Samuel Douglas Cupp

LSU Doctoral Dissertations

Current numerical codes can successfully evolve similar-mass binary black holes systems, and these numerical waveforms contributed to the success of the LIGO Collaboration's detection of gravitational waves. LIGO requires high resolution numerical waveforms for detection and parameter estimation of the source. Great effort was expended over several decades to produce the numerical methods used today. However, future detectors will require further improvements to numerical techniques to take full advantage of their detection capabilities. For example, the Laser Interferometer Space Antenna (LISA) will require higher resolution simulations of similar-mass-ratio systems than LIGO. LISA will also be able to detect extreme-mass-ratio inspiral …

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Introduction To Classical Field Theory, Charles G. Torre Jun 2022

Introduction To Classical Field Theory, Charles G. Torre

All Complete Monographs

This is an introduction to classical field theory. Topics treated include: Klein-Gordon field, electromagnetic field, scalar electrodynamics, Dirac field, Yang-Mills field, gravitational field, Noether theorems relating symmetries and conservation laws, spontaneous symmetry breaking, Lagrangian and Hamiltonian formalisms.

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All-Sky, All-Frequency Directional Search For Persistent Gravitational-Waves From Advanced Ligo's And Advanced Virgo's First Three Observing Runs, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, Teviet Creighton, Mario C. Diaz, F. Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang Jun 2022

All-Sky, All-Frequency Directional Search For Persistent Gravitational-Waves From Advanced Ligo's And Advanced Virgo's First Three Observing Runs, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, Teviet Creighton, Mario C. Diaz, F. Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang

Physics and Astronomy Faculty Publications and Presentations

We present the first results from an all-sky all-frequency (ASAF) search for an anisotropic stochastic gravitational-wave background using the data from the first three observing runs of the Advanced LIGO and Advanced Virgo detectors. Upper limit maps on broadband anisotropies of a persistent stochastic background were published for all observing runs of the LIGO-Virgo detectors. However, a broadband analysis is likely to miss narrowband signals as the signal-to-noise ratio of a narrowband signal can be significantly reduced when combined with detector output from other frequencies. Data folding and the computationally efficient analysis pipeline, PyStoch, enable us to perform the radiometer …

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Exploring Changes In Quasar Spectral Energy Distributions Across C Iv Parameter Space, Angelica B. Rivera, Gordon T. Richards, Sarah C. Gallagher, Trevor V. Mccaffrey, Amy L. Rankine, Paul C. Hewett, Ohad Shemmer Jun 2022

Exploring Changes In Quasar Spectral Energy Distributions Across C Iv Parameter Space, Angelica B. Rivera, Gordon T. Richards, Sarah C. Gallagher, Trevor V. Mccaffrey, Amy L. Rankine, Paul C. Hewett, Ohad Shemmer

Physics and Astronomy Publications

We examine the UV/X-ray properties of 1378 quasars in order to link empirical correlations to theoretical models of the physical mechanisms dominating quasars as a function of mass and accretion rate. The clarity of these correlations is improved when (1) using C iv broad emission line equivalent width (EQW) and blueshift (relative to systemic) values calculated from high signal-to-noise ratio reconstructions of optical/UV spectra and (2) removing quasars expected to be absorbed based on their UV/X-ray spectral slopes. In addition to using the traditional C iv parameter space measures of C iv EQW and blueshift, we define a “C iv …

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Images Of Embedded Jovian Planet Formation At A Wide Separation Around Ab Aurigae, Thayne Currie, Kellen Lawson, Glenn Schneider, Wladimir Lyra, John Wisniewski, Carol Grady, Olivier Guyon, Motohide Tamura, Takayuki Kotani, Hajime Kawahara, Timothy Brandt, Taichi Uyama, Takayuki Muto, Ruobing Dong, Tomoyuki Kudo, Jun Hashimoto, Misato Fukagawa, Kevin Wagner, Julien Lozi, Jeffrey Chilcote, Taylor Tobin, Tyler Groff, Kimberly Ward-Duong, William Januszewski, Barnaby Norris, Peter Tuthill, Nienke Van Der Marel, Michael Sitko, Vincent Deo, Sebastien Vievard, Nemanja Jovanovic, Frantz Martinache Jun 2022

Images Of Embedded Jovian Planet Formation At A Wide Separation Around Ab Aurigae, Thayne Currie, Kellen Lawson, Glenn Schneider, Wladimir Lyra, John Wisniewski, Carol Grady, Olivier Guyon, Motohide Tamura, Takayuki Kotani, Hajime Kawahara, Timothy Brandt, Taichi Uyama, Takayuki Muto, Ruobing Dong, Tomoyuki Kudo, Jun Hashimoto, Misato Fukagawa, Kevin Wagner, Julien Lozi, Jeffrey Chilcote, Taylor Tobin, Tyler Groff, Kimberly Ward-Duong, William Januszewski, Barnaby Norris, Peter Tuthill, Nienke Van Der Marel, Michael Sitko, Vincent Deo, Sebastien Vievard, Nemanja Jovanovic, Frantz Martinache

Astronomy: Faculty Publications

Direct images of protoplanets embedded in disks around infant stars provide the key to understanding the formation of gas giant planets such as Jupiter. Using the Subaru Telescope and the Hubble Space Telescope, we find evidence for a Jovian protoplanet around AB Aurigae orbiting at a wide projected separation (~93 au), probably responsible for multiple planet-induced features in the disk. Its emission is reproducible as reprocessed radiation from an embedded protoplanet. We also identify two structures located at 430–580 au that are candidate sites of planet formation. These data reveal planet formation in the embedded phase and a protoplanet discovery …

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Investigating The Thermodynamics And Seismic Profile Of The Europan Hydrosphere Through Pure-Water Modeling And Saltwater Experiments, Samantha Rosenfeld Jun 2022

Investigating The Thermodynamics And Seismic Profile Of The Europan Hydrosphere Through Pure-Water Modeling And Saltwater Experiments, Samantha Rosenfeld

Honors Theses

We explore the properties of the hydrosphere on Europa involving both a modeling technique and experimental methods. We perform a computational analysis of the thermodynamic properties for an ideal, pure-water Europan ice shell using a Python programming framework called SeaFreeze. We create four models assuming surface temperatures of either 50 K or 140 K and ice shell thicknesses of either 3 km or 30 km. We observe mostly linear trends for the density and seismic wave velocities with respect to depth and find that surface temperature has the greatest effect on the models. Simultaneously, we experimentally investigate the phase diagram …

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Helium-Like X-Ray Line Complexes Show That The Hottest Plasma On The O Supergiant Ζ Puppis Is In Its Wind, David H. Cohen, Ariel M. Overdorff, M. A. Leutenegger, M. Gagné, V. Petit, A. David-Uraz Jun 2022

Helium-Like X-Ray Line Complexes Show That The Hottest Plasma On The O Supergiant Ζ Puppis Is In Its Wind, David H. Cohen, Ariel M. Overdorff, M. A. Leutenegger, M. Gagné, V. Petit, A. David-Uraz

Physics & Astronomy Faculty Works

We present an analysis of Chandra grating spectra of key helium-like line complexes to put constraints on the location with respect to the photosphere of the hottest (T ≳ 6 × 10⁶ K) plasma in the wind of the O supergiant ζ Pup and to explore changes in the 18 yr between two sets of observations of this star. We fit two models—one empirical and one wind-shock-based—to the S XV, Si XIII, and Mg XI line complexes and show that an origin in the wind flow, above r ≈ 1.5 R∗, is strongly favoured over an origin less than 0.3 …

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Statistical Effects Of Synthetic Template Mismatch With Model Deimos Observations, Christos Kakogiannis Jun 2022

Statistical Effects Of Synthetic Template Mismatch With Model Deimos Observations, Christos Kakogiannis

Honors Theses

High-precision kinematics of individual stars in Milky Way satellite galaxies and globular clusters is crucial for studies of galaxy formation, cosmology, alternative gravity models, and dark matter. We tested a rigorous method that matches model DEIMOS observations of such targets with synthetic template spectra that deduces radial velocities and [Fe/H] abundances. We added noise to create a model spectrum with SNR = 30, fitted templates with different parameters to it, and calculated the
best-match velocity and the goodness of the fit. The best fits occur for templates that are close in parameter space to the model spectrum, and the fits …

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Toi-1696: A Nearby M4 Dwarf With A 3 R⊕ Planet In The Neptunian Desert, M. Mori, J. H. Livingston, J. De Leon, N. Narita, T. Hirano, A. Fukui, K. A. Collins, N. Fujita, Y. Hori, H. T. Ishikawa, K. Kawauchi, K. G. Stassun, N. Watanabe, S. Giacalone, R. Gore, A. Schroeder, C. D. Dressing, A. Bieryla, Eric L.N. Jensen, B. Massey, A. Shporer, M. Kuzuhara, D. Charbonneau, D. R. Ciardi, J. P. Doty, E. Esparza-Borges, H. Harakawa, K. Hodapp, M. Ikoma, K. Ikuta, K. Isogai, J. M. Jenkins, T. Kagetani, T. Kimura, T. Kodama, T. Kotani, V. Krishnamurthy, T. Kudo, S. Kurita, T. Kurokawa, N. Kusakabe, D. W. Latham, B. Mclean, F. Murgas, J. Nishikawa, T. Nishiumi, M. Omiya, H. P. Osborn, E. Palle, H. Parviainen, G. R. Ricker, S. Seager, T. Serizawa, H.-Y. Teng, Y. Terada, J. D. Twicken, A. Ueda, R. Vanderspek, S. Vievard, J. N. Winn, Y. Zou, M. Tamura Jun 2022

Toi-1696: A Nearby M4 Dwarf With A 3 R⊕ Planet In The Neptunian Desert, M. Mori, J. H. Livingston, J. De Leon, N. Narita, T. Hirano, A. Fukui, K. A. Collins, N. Fujita, Y. Hori, H. T. Ishikawa, K. Kawauchi, K. G. Stassun, N. Watanabe, S. Giacalone, R. Gore, A. Schroeder, C. D. Dressing, A. Bieryla, Eric L.N. Jensen, B. Massey, A. Shporer, M. Kuzuhara, D. Charbonneau, D. R. Ciardi, J. P. Doty, E. Esparza-Borges, H. Harakawa, K. Hodapp, M. Ikoma, K. Ikuta, K. Isogai, J. M. Jenkins, T. Kagetani, T. Kimura, T. Kodama, T. Kotani, V. Krishnamurthy, T. Kudo, S. Kurita, T. Kurokawa, N. Kusakabe, D. W. Latham, B. Mclean, F. Murgas, J. Nishikawa, T. Nishiumi, M. Omiya, H. P. Osborn, E. Palle, H. Parviainen, G. R. Ricker, S. Seager, T. Serizawa, H.-Y. Teng, Y. Terada, J. D. Twicken, A. Ueda, R. Vanderspek, S. Vievard, J. N. Winn, Y. Zou, M. Tamura

Physics & Astronomy Faculty Works

We present the discovery and validation of a temperate sub-Neptune around the nearby mid-M dwarf TIC 470381900 (TOI-1696), with a radius of 3.09 ± 0.11 R⊕ and an orbital period of 2.5 days, using a combination of Transiting Exoplanets Survey Satellite (TESS) and follow-up observations using ground-based telescopes. Joint analysis of multiband photometry from TESS, Multicolor Simultaneous Camera for studying Atmospheres of Transiting exoplanets (MuSCAT), MuSCAT3, Sinistro, and KeplerCam confirmed the transit signal to be achromatic as well as refined the orbital ephemeris. High-resolution imaging with Gemini/'Alopeke and high-resolution spectroscopy with the Subaru InfraRed Doppler (IRD) confirmed that there …

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Recreating Nasa Images Using Hubble Data: Two Populations Of Stars In Messier 5, Adam N. Looper Jun 2022

Recreating Nasa Images Using Hubble Data: Two Populations Of Stars In Messier 5, Adam N. Looper

Physics

This project seeks to recreate a color photo from NASA using Hubble data that shows the two distinct populations of stars in the cluster. Although the colored image displays the two types of stars, scientists often recolor astronomical pictures for two reasons: in order to clearly define objects, or to convert an image taken outside the visible spectrum into color. Thus, overlapping Hubble images colored according to filter should verify that there are two populations of stars in Messier 5, and the colored NASA photograph is valid in highlighting the unusual distribution of stars.

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A Comparison Of Exotic And Pyraf In Analyzing Exoplanet Transits, Kailei A. Gallup Jun 2022

A Comparison Of Exotic And Pyraf In Analyzing Exoplanet Transits, Kailei A. Gallup

Physics

In this paper we discuss the data analysis processes using PyRaf, a Python-based version of IRAF, which is one of the most commonly used coding softwares in the astronomy community, as well as the analysis process using EXOTIC. Additionally, we will compare the outcomes from each process to determine if either has significant benefits over the other.

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A Self-Consistent Model For Brown Dwarf Populations, R. E. Ryan Jr., P. Thorman, C. Aganze, A. J. Burgasser, S. H. Cohen, N. P. Hathi, Benne Holwerda, N. Pirzkal, R. A. Windhorst Jun 2022

A Self-Consistent Model For Brown Dwarf Populations, R. E. Ryan Jr., P. Thorman, C. Aganze, A. J. Burgasser, S. H. Cohen, N. P. Hathi, Benne Holwerda, N. Pirzkal, R. A. Windhorst

Faculty and Staff Scholarship

We present a self-consistent model of the Milky Way to reproduce the observed distributions (spectral type, absolute J-band magnitude, effective temperature) and total velocity dispersion of brown dwarfs. For our model, we adopt parametric forms for the star formation history and initial-mass function, published evolutionary models, and theoretical age–velocity relations. Using standard Markov Chain Monte Carlo methods, we derive a power-law index of the initial-mass function of α = −0.71 ± 0.11, which is an improvement over previous studies. We consider a gamma-function form for the star formation history, though we find that this complex model is only slightly …

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Waves And Oscillations In A Sunspot: Observations And Modeling Of Noaa Ar 12470, Yi Chai May 2022

Waves And Oscillations In A Sunspot: Observations And Modeling Of Noaa Ar 12470, Yi Chai

Dissertations

Waves and oscillations are important solar phenomena not only because they can propagate and dissipate energy in the chromosphere, but also because they carry information about the structure of the atmosphere in which they propagate. Among these phenomena, the one of the most interesting ones occurs in the sunspot umbra. In this area, continuously propagating magnetohydrodynamic (MHD) waves generated from below the photosphere create the famous 3-minute sunspot umbral oscillations that affect the line profile of spectral lines due to temperature, density, and velocity changes of the plasma in the region. In the past decades, numerous observations and models have …

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Correlations Between The Rotations And Magnetospheres Of The Terrestrial Planets And The Sun's Formation In Our Solar System, Fred J. Cadieu May 2022

Correlations Between The Rotations And Magnetospheres Of The Terrestrial Planets And The Sun's Formation In Our Solar System, Fred J. Cadieu

Publications and Research

Correlations between the rotations of the terrestrial planets in our solar system and the magnetic field of the Sun have been previously noted. These correlations account for the opposite rotation of Venus as a result of the magnetic field of the Sun being dragged across the conducting core of Venus. Currently the Sun’s magnetic field is not sufficiently strong to account for the proposed correlations. But recently meteorite paleomagnetism measurements have indicated that during the Sun’s formation the magnetic field of the Sun was of sufficient strength to have resulted in the observed correlations. As a part of these correlations …

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Searches For Gravitational Waves From Known Pulsars At Two Harmonics In The Second And Third Ligo-Virgo Observing Runs, R. Abbott, H. Abe, F. Acernese, Teviet Creighton, M. G. Benjamin, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang May 2022

Searches For Gravitational Waves From Known Pulsars At Two Harmonics In The Second And Third Ligo-Virgo Observing Runs, R. Abbott, H. Abe, F. Acernese, Teviet Creighton, M. G. Benjamin, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang

Physics and Astronomy Faculty Publications and Presentations

We present a targeted search for continuous gravitational waves (GWs) from 236 pulsars using data from the third observing run of LIGO and Virgo (O3) combined with data from the second observing run (O2). Searches were for emission from the l = m = 2 mass quadrupole mode with a frequency at only twice the pulsar rotation frequency (single harmonic) and the l = 2, m = 1, 2 modes with a frequency of both once and twice the rotation frequency (dual harmonic). No evidence of GWs was found, so we present 95% credible upper limits on the strain amplitudes …

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X-Ray Observation Of The Roche-Lobe-Filling White Dwarf Plus Hot Subdwarf System Ztf J213056.71+442046.5, S. Mereghetti, N. La Palombara, T. Kupfer, T. R. Marsh, C. M. Copperwheat, K. Deshmukh, P. Esposito, T. Maccarone, F. Pintore, Liliana Rivera Sandoval May 2022

X-Ray Observation Of The Roche-Lobe-Filling White Dwarf Plus Hot Subdwarf System Ztf J213056.71+442046.5, S. Mereghetti, N. La Palombara, T. Kupfer, T. R. Marsh, C. M. Copperwheat, K. Deshmukh, P. Esposito, T. Maccarone, F. Pintore, Liliana Rivera Sandoval

Physics and Astronomy Faculty Publications and Presentations

ZTF J213056.71+442046.5 is the prototype of a small class of recently discovered compact binaries composed of a white dwarf and a hot subdwarf that fills its Roche lobe. Its orbital period of only 39 minutes is the shortest known for the objects in this class. Evidence for a high orbital inclination (i = 86°) and for the presence of an accretion disk has been inferred from a detailed modeling of its optical photometric and spectroscopic data. We report the results of an XMM-Newton observation carried out on 2021 January 7. ZTF J213056.71+442046.5 was clearly detected by the Optical Monitor, …

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To The Moon And Mars And Back To The Archives: Working With Modern Space Collections At The University Of Arizona Libraries, Molly Stothert-Maurer, Lisa E. Duncan May 2022

To The Moon And Mars And Back To The Archives: Working With Modern Space Collections At The University Of Arizona Libraries, Molly Stothert-Maurer, Lisa E. Duncan

Journal of Western Archives

With a long history at the University of Arizona with excellence in the lunar and planetary sciences, the University of Arizona Libraries Special Collections has increased its collecting of the History of Science and Technology. These large, modern space collections pose unique challenges and require specific needs to be addressed in order for the collections to be stored, processed and made available for access. It is essential for archivists working with these collections to ask their donors the right questions and learn the limitations and restrictions that often come with acquiring modern space collections. Archives around the country have started …

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Du Undergraduate Showcase: Research, Scholarship, And Creative Works: Abstracts, Emma Aggeler, Elena Arroway, Daisy T. Booker, Justin Bravo, Kyle Bucholtz, Megan Burnham, Nicole Choi, Spencer Cockerell, Rosie Contino, Jackson Garske, Kaitlyn Glover, Caroline Hamilton, Haley Hartmann, Madalyne Heiken, Colin Holter, Leah Huzjak, Alyssa Jeng, Cole Jernigan, Chad Kashiwa, Adelaide Kerenick, Emily King, Abigail Langeberg, Maddie Leake, Meredith Lemons, Alec Mackay, Greer Mckinley, Ori Miller, Guy Milliman, Katherine Miromonti, Audrey Mitchell, Lauren Moak, Megan Morrell, Gelella Nebiyu, Zdenek Otruba, Toni V. Panzera, Kassidy Patarino, Sneha Patil, Alexandra Penney, Kevin Persky, Caitlin Pham, Gabriela Recinos, Mary Ringgenberg, Chase Routt, Olivia Schneider, Roman Shrestha, Arlo Simmerman, Alec Smith, Tessa Smith, Nhi-Lac Thai, Kyle Thurmann, Casey Tindall, Amelia Trembath, Maria Trubetskaya, Zachary Vangelisti, Peter Vo, Abby Walker, David Winter, Grayden Wolfe, Leah York May 2022

Du Undergraduate Showcase: Research, Scholarship, And Creative Works: Abstracts, Emma Aggeler, Elena Arroway, Daisy T. Booker, Justin Bravo, Kyle Bucholtz, Megan Burnham, Nicole Choi, Spencer Cockerell, Rosie Contino, Jackson Garske, Kaitlyn Glover, Caroline Hamilton, Haley Hartmann, Madalyne Heiken, Colin Holter, Leah Huzjak, Alyssa Jeng, Cole Jernigan, Chad Kashiwa, Adelaide Kerenick, Emily King, Abigail Langeberg, Maddie Leake, Meredith Lemons, Alec Mackay, Greer Mckinley, Ori Miller, Guy Milliman, Katherine Miromonti, Audrey Mitchell, Lauren Moak, Megan Morrell, Gelella Nebiyu, Zdenek Otruba, Toni V. Panzera, Kassidy Patarino, Sneha Patil, Alexandra Penney, Kevin Persky, Caitlin Pham, Gabriela Recinos, Mary Ringgenberg, Chase Routt, Olivia Schneider, Roman Shrestha, Arlo Simmerman, Alec Smith, Tessa Smith, Nhi-Lac Thai, Kyle Thurmann, Casey Tindall, Amelia Trembath, Maria Trubetskaya, Zachary Vangelisti, Peter Vo, Abby Walker, David Winter, Grayden Wolfe, Leah York

DU Undergraduate Research Journal Archive

Abstracts from the DU Undergraduate Showcase.

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Analysis Of Comet Rotation Through Modeling Of Features In The Coma, Ien Harris May 2022

Analysis Of Comet Rotation Through Modeling Of Features In The Coma, Ien Harris

Theses and Dissertations

An integral field unit fiber array spectrograph was used to observe the emission spectra of radical species (C2, C3, CH, CN, and NH2) in multiple comets. The resultant azimuthal and radial division maps produced from the reduced data provide a unique method of analyzing features with these radicals in the comae, as well as how they behave over time. A Monte Carlo model was developed in order to simulate the behavior of particles from the outer nucleus and coma of each comet depending on various parameters including rotational period, outflow velocity, and active area location. The results from the model …

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Twisting Lasers With The Faraday Effect, Harrison Werrell May 2022

Twisting Lasers With The Faraday Effect, Harrison Werrell

Macalester Journal of Physics and Astronomy

Our objective with this project was to create a system and procedure to quantify the magnetization of a material with polarized light by using the Faraday Effect, where the light is rotated according to the magnetization. This type of system has seen use in technologies such as magneto-optical drives and optical isolators, and is part of the study of optical materials, along with the similar MagnetoOptical Kerr Effect. Our system, specifically, is intended to be used as part of an advanced Physics Lab in the future. It uses an electromagnet to magnetize a sample, and a laser to observe the …

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Electrical Analysis Of A Pem Electrolysis Cell, Joey Wehrley, James Doyle May 2022

Electrical Analysis Of A Pem Electrolysis Cell, Joey Wehrley, James Doyle

Macalester Journal of Physics and Astronomy

Polymer Electrolyte Membrane (PEM) electrolysis is a form of electrolysis that is heavily used in commercial capacities. It functions by using a membrane and an electric charge in order to perform electrolysis water, splitting it into its component parts - Hydrogen and Oxygen. These parts can then be used in a number of different applications, including reversing the electrolysis process to regenerate some energy in the form of electricity. During this experiment, multiple currents were run through a PEM cell, and voltages across the membrane were measured. It was found that a standard R/C charging model can be fit to …

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Neutrino Oscillations In The Presence Of A Magnetic Field, Chinhsan Sieng May 2022

Neutrino Oscillations In The Presence Of A Magnetic Field, Chinhsan Sieng

Macalester Journal of Physics and Astronomy

We calculate oscillation probabilities in the presence of an external magnetic field in a one-generation neutrino framework that includes both Majorana and Dirac mass terms. First, we write down the Euler-Lagrange equations and obtain a system of eight differential equations coupling together eight different neutrino states that can be distinguished by helicity, chirality, and particle/antiparticle-ness. We then solve this system of differential equations in various special cases, exhibiting different types of oscillations. When the magnetic field is in the direction of momentum, there are only four oscillation channels as helicity flip is forbidden. We observe that chirality flips are suppressed …

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The Impact Of Initial Abundances On Modeling The Weak S-Process, Lev S. Serxner May 2022

The Impact Of Initial Abundances On Modeling The Weak S-Process, Lev S. Serxner

Macalester Journal of Physics and Astronomy

No abstract provided.

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The Survey Of Hi In Extremely Low-Mass Dwarfs: New Results From Vla Imaging, Francesco Pecere, John M. Cannon, Damen Beverlin, Jackson Codd May 2022

The Survey Of Hi In Extremely Low-Mass Dwarfs: New Results From Vla Imaging, Francesco Pecere, John M. Cannon, Damen Beverlin, Jackson Codd

Macalester Journal of Physics and Astronomy

We present new HI spectral line imaging of 19 galaxies in the “Survey of HI in Extremely Low-mass Dwarfs” (SHIELD) acquired for Large Program VLA/ 20A-330. Using the National Radio Astronomy Observatory’s Karl G. Jansky Very Large Array (VLA) in the C configuration, we produce images of the neutral interstellar medium (HI) on angular scales of 15 to 20 arcseconds (corresponding to physical resolutions of 200 to 1100 parsecs). The three-dimensional cubes probe the morphology and kinematics of the gas at a range of spatial and spectral resolutions. The cubes were collapsed to produce two-dimensional moment maps (representing HI mass …

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Hunting For Fast Radio Bursts From Messier 82: Exploring The Frb--Magnetar Connection, Susie Paine May 2022

Hunting For Fast Radio Bursts From Messier 82: Exploring The Frb--Magnetar Connection, Susie Paine

Macalester Journal of Physics and Astronomy

Fast radio bursts (FRBs) are short-duration radio pulses of cosmological origin. Among the most common sources predicted to explain this phenomenon are bright pulses from a class of extremely highly magnetized neutron stars known as magnetars. In 2020, a Galactic magnetar produced an FRB-like burst, allowing researchers to constrain the Galactic magnetar burst rate. We assume that the magnetar burst rate scales with star formation rate and test an important prediction for similar bursts in nearby galaxies. Messier 82 (M82) has a star formation rate 40 times that of the Milky Way, implying that the magnetar burst rate would be …

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Molecular Line Search In Archival Alma Imaging Of M87, Xueyi Li May 2022

Molecular Line Search In Archival Alma Imaging Of M87, Xueyi Li

Macalester Journal of Physics and Astronomy

We present a molecular line search in spectral imaging of the elliptical galaxy M87 using archival data from the Atacama Large Millimeter/sub-millimeter Array (ALMA). The primary goal of this project is to verify and characterize possible CO transition lines, which can be used for future studies to determine the dynamics of the system, or the mass of the supermassive black hole (BH) in the center of the galaxy. After performing extensive atmospheric modeling, we found that most of the absorption features have a corresponding atmospheric ozone transition, so it is unlikely that these features are either Galactic or extragalactic. We …

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