Astrophysics and Astronomy Commons^™

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.

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 …

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 …

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 …

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 & Astronomy Faculty Publications

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 …

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 & Astronomy Faculty Publications

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, …

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 …

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.

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 …

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 …

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 …

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 …

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

Macalester Journal of Physics and Astronomy

No abstract provided.

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 …

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 …

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 …

Lie Algebras And The Poincare Group, Jack Hempel Costello

Macalester Journal of Physics and Astronomy

This paper will discuss my research with
Professor Tonnis ter Veldhuis on the Poincare Group
and other similar algebraic approaches based on the
Minkowski Metric. This paper will begin with an
introduction discussing group theory and expand on its
specific applications in theoretical physics.

Simulating Interactions Between Coronal Mass Ejections, Damen S. Beverlin, Tatiana Niembro

Macalester Journal of Physics and Astronomy

Coronal mass ejections (CMEs) launch large amounts of plasma and magnetic fields into the interplanetary medium. Under the right initial conditions, this ejecta can reach Earth and cause issues with electronic devices. As such, we would like to have an accurate model that depicts how these CMEs propagate as they leave the sun. By using fluid dynamics and one-minute resolution in-situ solar wind data, we sought to simulate CME plasma propagation with analytical and numerical models. Because the interstellar medium contains other material and other events happen on the sun simultaneously, CMEs can interact with each other and other ejecta, …

Custom Calibration And Correction Of Photoemission Electron Microscope Images Using Graphene, Henry Bell

Macalester Journal of Physics and Astronomy

The Photoemission Electron Microscope (PEEM) is a full-field electron microscope that utilizes the photoelectric effect to image a surface. Due to a spatial resolution on the order of 10 nanometers and its ability to image both the morphology of a surface and its band structure, it is a useful tool for understanding the properties of materials for use in electronic devices. To correct for random sample misalignment and the experimental frame of reference in the spectroscopy mode of the PEEM, the 3D dataset must be rotated in both the momentum and energy coordinates which requires pixel calibration and energy alignment. …

All-Sky Search For Gravitational Wave Emission From Scalar Boson Clouds Around Spinning Black Holes In Ligo O3 Data, R. Abbott, H. Abe, F. Acernese, Michael G. Benjamin, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

This paper describes the first all-sky search for long-duration, quasimonochromatic gravitational-wave signals emitted by ultralight scalar boson clouds around spinning black holes using data from the third observing run of Advanced LIGO. We analyze the frequency range from 20 to 610 Hz, over a small frequency derivative range around zero, and use multiple frequency resolutions to be robust towards possible signal frequency wanderings. Outliers from this search are followed up using two different methods, one more suitable for nearly monochromatic signals, and the other more robust towards frequency fluctuations. We do not find any evidence for such signals and set …

All-Sky Search For Gravitational Wave Emission From Scalar Boson Clouds Around Spinning Black Holes In Ligo O3 Data, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

This paper describes the first all-sky search for long-duration, quasimonochromatic gravitational-wave signals emitted by ultralight scalar boson clouds around spinning black holes using data from the third observing run of Advanced LIGO. We analyze the frequency range from 20 to 610 Hz, over a small frequency derivative range around zero, and use multiple frequency resolutions to be robust towards possible signal frequency wanderings. Outliers from this search are followed up using two different methods, one more suitable for nearly monochromatic signals, and the other more robust towards frequency fluctuations. We do not find any evidence for such signals and set …

Machine Learning Techniques For Pile-Up Rejection In Cryogenic Calorimeters, G. Fantini, A. Armatol, E. Armengaud, W. Armstrong, Frank Avignone Iii, O. Azzolini, A. Barabash, G. Bari, D. Baudin, F. Bellini, G. Benato, M. Beretta, L. Bergé, M. Biassoni, J. Billard, V. Boldrini, A. Branca, C. Brofferio, C. Bucci, J. Camilleri, Carl Rosenfeld, Carl Rosenfeld, Jeffery R. Wilson, Et. Al.

Faculty Publications

CUORE Upgrade with Particle IDentification (CUPID) is a foreseen ton-scale array of Li₂MoO₄ (LMO) cryogenic calorimeters with double readout of heat and light signals. Its scientific goal is to fully explore the inverted hierarchy of neutrino masses in the search for neutrinoless double beta decay of ¹⁰⁰Mo. Pile-up of standard double beta decay of the candidate isotope is a relevant background. We generate pile-up heat events via injection of Joule heater pulses with a programmable waveform generator in a small array of LMO crystals operated underground in the Laboratori Nazionali del Gran Sasso, Italy. This allows …

Ligers Interferometric Survey Of M Dwarf Diameters, Tyler Gregory Ellis

LSU Doctoral Dissertations

In this dissertation, I present the largest single collection of M dwarf stellar radii in over a decade and contextualize these measurements with the systematic model discrepancies. The measurements of stellar angular diameters are also important in the quantification of the properties of exoplanets. In order to estimate the property of the exoplanet, it is first necessary to quantify the properties of the planet's host star. Using the survey results complemented with previous direct observations of the angular diameters of low mass stars, I develop updated updated surface brightness relationships. These relationships allow predictions of angular diameters using easy to …

Galaxy And Mass Assembly (Gama): Self-Organizing Map Application On Nearby Galaxies, Benne W. Holwerda, Dominic Smith, Lori Porter, Chris Henry, Ren Porter-Temple, Kyle Cook, Kevin A. Pimbblet, Andrew M. Hopkins, Maciej Bilicki, Sebastian Turner, Viviana Acquaviva, Lingyu Wang, Angus H. Wright, Lee S. Kelvin, Meiert W. Grootes

Faculty and Staff Scholarship

Galaxy populations show bimodality in a variety of properties: stellar mass, colour, specific star-formation rate, size, and Sérsic index. These parameters are our feature space. We use an existing sample of 7556 galaxies from the Galaxy and Mass Assembly (GAMA) survey, represented using five features and the K-means clustering technique, showed that the bimodalities are the manifestation of a more complex population structure, represented by between two and six clusters. Here we use Self-Organizing Maps (SOM), an unsupervised learning technique that can be used to visualize similarity in a higher dimensional space using a 2D representation, to map these 5D …

Topological Changes In The Magnetic Field Of Lq Hya During An Activity Minimum, Jyri J. Lehtinen, Maarit J. Käpylä, Thomas Hackman, Oleg Kochukhov, Teemu Willamo, Stephen C. Marsden, Sandra V. Jeffers, Gregory W. Henry, Lauri Jetsu

Information Systems and Engineering Management Research Publications

Aims. Previous studies have related surface temperature maps, obtained with the Doppler imaging (DI) technique, of LQ Hya with long-term photometry. Here, we compare surface magnetic field maps, obtained with the Zeeman Doppler imaging (ZDI) technique, with contemporaneous photometry, with the aim of quantifying the star’s magnetic cycle characteristics.

Methods. We inverted Stokes IV spectropolarimetry, obtained with the HARPSpol and ESPaDOnS instruments, into magnetic field and surface brightness maps using a tomographic inversion code that models high signal-to-noise ratio mean line profiles produced by the least squares deconvolution (LSD) technique. The maps were compared against long-term ground-based photometry acquired with …

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

Earth & Space Sciences Faculty Publications

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 greater than or similar to 6 x 10(6) K) plasma in the wind of the O supergiant zeta 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 approximate to 1.5 R*, …

Aloso: Spectroscopy And Structure Of A New Group Of Astrochemical Molecules, Vincent J. Esposito, Tarek Trabelsi, Joseph S. Francisco

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

No abstract provided.

Optimization Of Orbital Trajectories Using Neuroevolution Of Augmenting Topologies, Nathan Wetherell

University Scholar Projects

This project aims to determine the feasibility of using NeuroEvolution of Augmenting Topologies (NEAT), an advanced neural network evolution scheme, to optimize orbital transfer trajectories. More specifically, this project compares a genetically evolved neural network to a standard Hohmann transfer between Earth and Mars. To test these two methods, an N-body simulation environment was created to accurately determine the result of gravitational interactions on a theoretical spacecraft when combined with planned engine burns. Once created, this simulation environment was used to train the neural networks created using the NEAT Python module. A genetic algorithm was used to modify the topology …

First Test Of Lepton Flavor Universality In The Charmed Baryon Decays Ωc0 → Ω-ℓ+Νℓ Using Data Of The Belle Experiment, Y. B. Li, C. P. Shen, I. Adachi, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, P. Behera, K. Belous, J. Bennett, F. Bernlochner, M. Bessner, B. Bhuyan, T. Bilka, A. Bobrov

Faculty and Student Publications

We present the first observation of the ωc0→ω-μ+νμ decay and present measurements of the branching fraction ratios of the ωc0→ω-ℓ+νℓ decays compared to the reference mode ωc0→ω-π+, (ℓ=e or μ). This analysis is based on 89.5 fb-1, 711 fb-1, and 121.1 fb-1 data samples collected with the Belle detector at the KEKB asymmetric-energy e+e- collider at the center-of-mass energies of 10.52 GeV, 10.58 GeV, and 10.86 GeV, respectively. The ωc0 signal yields are extracted by fitting Mωℓ and Mωπ spectra. The branching fraction ratios B(ωc0→ω-e+νe)/B(ωc0→ω-π+) and B(ωc0→ω-μ+νμ)/B(ωc0→ω-π+) are measured to be 1.98±0.13(stat)±0.08(syst) and 1.94±0.18(stat)±0.10(syst), respectively. The ratio of B(ωc0→ω-e+νe)/B(ωc0→ω-μ+νμ) is …

Monitoring The M-Dwarf Host Stars Of Tess Exoplanet Candidates: Stellar Flares And Habitability, Ashley Lieber

Physics Undergraduate Honors Theses

In the search for life beyond our solar system, the study of M-dwarfs has become increasingly important due to their unique characteristics including their small size, flaring capabilities, and long lifespans. Their small size allows for exoplanet detection due to observable gravitational interactions, and the stellar flares could potentially trigger prebiotic life on exoplanets in the system. Lastly, their long lifespans may provide the conditions necessary to foster prebiotic life and the development of more complex organisms over time. Flare rate is a critical factor in determining the habitability of the exoplanet due to its potential to damage or incubate …