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Articles 1 - 30 of 83
Full-Text Articles in Astrophysics and Astronomy
Survey Of Possible Magnetic Field Sources Around The Intragroup Medium Of Ngc 2563, Edward A. Wallace, Anna Williams
Survey Of Possible Magnetic Field Sources Around The Intragroup Medium Of Ngc 2563, Edward A. Wallace, Anna Williams
Macalester Journal of Physics and Astronomy
The origin and evolution of magnetic fields in space is an ongoing mystery in astronomy. Previous work has concluded the existence of magnetic fields in galaxy clusters, and to build an evolutionary model, the motivation behind this project is to determine how these magnetic fields form. In order to answer this question, we want to search for magnetic fields in galaxy group NGC 2563. To do this, our project determines the contribution to observed rotation measures of the galaxy group that come from the Milky Way and from the sources themselves.
Modelling Of The Overcontact Eclipsing Binary V826 Aur, Kalev T. Murray-Rouse, John M. Cannon, Anna Williams, Wes Tobin
Modelling Of The Overcontact Eclipsing Binary V826 Aur, Kalev T. Murray-Rouse, John M. Cannon, Anna Williams, Wes Tobin
Macalester Journal of Physics and Astronomy
We present a model of the eclipsing binary system V826 Aur using differential photometric data from the Robert L. Mutel Telescope (RLMT) at the Winer Observatory in Sonoita, Arizona. The calculated time of superconjunction was found to be 60648.7658534 and the period was 0.361701 d. These values were used to generate a best-fit model of the eclipsing binary with the PHOEBE program. The best-fit modelled parameters were found to be: mass ratio (𝑞) is equal to 2.769, the inclination (𝑖) is equal to 80.45◦, the fillout factor (𝑓) equals 0.0961, and the temperature ratio (𝑇2∕𝑇1) is 0.9740. Although not statistically …
Finding High Mass X-Ray Binaries In Ngc 3109, Caeden Miller, John (Jay) Gallagher Iii
Finding High Mass X-Ray Binaries In Ngc 3109, Caeden Miller, John (Jay) Gallagher Iii
Macalester Journal of Physics and Astronomy
High Mass X-Ray Binary systems can be difficult to find in the Milky Way due to high metallicity contributing to mass loss due to stellar wind, so we turn our attention to the galaxy NGC 3109 in order to find these systems. Using archival data from the Hubble Space Telescope using the Wide Field Camera 3, we do photometry in both the F475W and F814W filters for the two fields of view that cover the galaxy. We then plot these magnitudes on a color-magnitude diagram and use isochrones of 5 and 10 million years to gather minimum mass estimates of …
Making And Breaking Chaos: Analog Computer Implementation Of The Lorenz Model, Reed Lefevre, James Doyle
Making And Breaking Chaos: Analog Computer Implementation Of The Lorenz Model, Reed Lefevre, James Doyle
Macalester Journal of Physics and Astronomy
Hybrid analogue-digital computers have been shown to have certain advantages over traditional digital computers when solving nonlinear partial differential equations. Motivated by this fact, we implement the Lorenz equations on an analogue electronic computer and vary the parameters to analyze the bifurcations. With the working circuit, we compared experimental results to various digital simulations to assess the effectiveness of our circuit. We find clear qualitative agreement between the physical circuit and digital simulations; however, we observe a noticeable quantitative difference in behavior. The circuit depicts a picturesque Lorenz Butterfly plot and bifurcates into fixed points and chaos; however, these bifurcations …
Non-Destructive Compositional Analysis Of Lead Halide Perovskite Films Using Thz Spectroscopy And A Three-Oscillator Dielectric Model, Isaac J.C Kisker
Non-Destructive Compositional Analysis Of Lead Halide Perovskite Films Using Thz Spectroscopy And A Three-Oscillator Dielectric Model, Isaac J.C Kisker
Macalester Journal of Physics and Astronomy
Terahertz (THz) Spectroscopy offers a novel approach to probing low-energy phonon excitation in complex crystalline materials like methylammonium lead iodide (MAPI) perovskite films. In this research, we use time-resolved Terahertz Spectroscopy in tandem with a three-oscillator model to non-destructively ascertain the relative volumetric composition of MAPI and residual lead iodide (PbI₂) in spin-coated films. The dielectric function is modeled as a product over longitudinal and transverse optical phonon modes. This model is then fitted to the measured THz spectra, allowing us to extract the contributions from both MAPI and PbI₂.
Examining Mulit-Wavelength Variability And Magnetic Interactions In The Polar St Lmi, Cain Rinkoski
Examining Mulit-Wavelength Variability And Magnetic Interactions In The Polar St Lmi, Cain Rinkoski
Macalester Journal of Physics and Astronomy
Cataclysmic variable (CV) stars are interacting binary systems that exhibit exotic, multi-wavelength behavior driven by mass transfer from a donor star onto a white dwarf. As rich laboratories for accretion physics, binary dynamics, and the origins of Type Ia supernovae, CVs have been well studied in the X-ray, ultraviolet, optical, and infrared—but remain comparatively underexplored in the radio regime. This paper presents simultaneous, time-resolved optical and radio observations of the magnetic CV ST LMi, aimed at constraining its emission mechanisms and orbital modulation.
The optical light curves display brightness variations of approximately 1.31 ± 0.02 magnitudes on a period of …
A Thermal Control System For The Atlas Hgtd Module Construction Process, Keelin B. Murphy
A Thermal Control System For The Atlas Hgtd Module Construction Process, Keelin B. Murphy
Macalester Journal of Physics and Astronomy
In the aim of simplifying the production process of 2000 HGTD (High Granularity Timing Detector) modules at IJClab for the high luminosity phase of the ATLAS experiment at the CERN Large Hadron Collider, I designed, coded, and constructed an automatic temperature control system for module assembly and testing. To this end, I examined the module’s thermal response to changes in air temperature using a climate chamber and to various currents fed through a Peltier device situated under the module. I adapted the Peltier setup into a fully independent control system driven by an Arduino microcontroller running a PID feedback loop.
Probing Charge Recombination In Organic Solar Cells, Ally C. Hurd, Awwad Alotaibi, Acacia Patterson, Obaid Alqahtani, James Doyle, Brian Akira Collins
Probing Charge Recombination In Organic Solar Cells, Ally C. Hurd, Awwad Alotaibi, Acacia Patterson, Obaid Alqahtani, James Doyle, Brian Akira Collins
Macalester Journal of Physics and Astronomy
Printable and flexible organic solar panels are promising sources of inexpensive, large-scale renewable energy, where panels can be manufactured by printing from polymer inks. There are some limitations to these types of solar cells, however. First, toxic halogenated solvents have historically been necessary to dissolve polymers to make the ink. In addition, organic solar cells typically have high rates of recombination, which limits their efficiency. Here, we use a transient photovoltage (TPV) technique to measure charge lifetimes in cells made from two different organic solvents. The first solvent is toxic, halogenated dichlorobenzene (DCB) which is typically used to make organic …
Investigation Of Tantalum Sodium Lead Borate Glass Using Laser Ionization Time Of Flight Mass Spectrometry (Litof-Ms), Siri Erickson-Green
Investigation Of Tantalum Sodium Lead Borate Glass Using Laser Ionization Time Of Flight Mass Spectrometry (Litof-Ms), Siri Erickson-Green
Macalester Journal of Physics and Astronomy
Laser ionization time of flight mass spectrometry (LITOF-MS) is a spectrometry method which can measure, with exceptional accuracy, the composition of ions within a glass system. Additionally, unlike other spectroscopy and spectrometry methods, this technique allows insight into the abundance of each kind of ion within a given glass system. This specific project tackled the topic of tantalum-doped sodium and lead borate glasses, as sodium and lead borate glasses doped with a transition metal is a topic which has not been thoroughly explored. Our group synthesized such a glass and was able to use LITOF-MS to gain insights into how …
Strain Methods For Changing Local Electric Field Gradient In Bafe2as2, Caleb Williams
Strain Methods For Changing Local Electric Field Gradient In Bafe2as2, Caleb Williams
Macalester Journal of Physics and Astronomy
In this study, we introduce a novel approach aimed at advancing the investigation of local nematicity in BaFe2As2 via dynamically pulsed strain fields. Our research is motivated by the pursuit of a more sensitive alternative to existing static strain methods. Employing nuclear magnetic resonance techniques, we measure the nuclear quadrupolar energy splittings, utilizing them as a sensitive indicator of the electric field gradient (EFG) that couples strongly to the orbital occupations of the 75As p-orbitals. In the new method, we discern an EFG response through changes in the phase acquired by the nuclear magnetization while time-evolving in the strain field, …
Linking The Population Of Binary Black Holes With The Stochastic Gravitational-Wave Background, Olivia X. Laske
Linking The Population Of Binary Black Holes With The Stochastic Gravitational-Wave Background, Olivia X. Laske
Macalester Journal of Physics and Astronomy
The astrophysical stochastic gravitational-wave background (SGWB) is the product of overlapping waveforms that create a single unresolvable background. While current LIGO sensitivity is insufficient to uncover the SGWB, future space-based detectors and Third Generation (3G) experiments are expected to probe deep enough for detection. Predictions of the SGWB can constrain future searches as well as provide insight into star formation, merger history, and mass distribution. Here, three primary methods are used to calculate a theoretical SGWB. The first method integrates over a precomputed mass distribution probability grid, while the second and third employ Monte Carlo integration with simulated data. After …
Simulation Of Polymerization On Surfaces: Implications For Abiogenesis, Sylvia Greene
Simulation Of Polymerization On Surfaces: Implications For Abiogenesis, Sylvia Greene
Macalester Journal of Physics and Astronomy
How did life arise from the prebiotic conditions of the early earth? This problem has vexed scientists for decades with no consensus on its solution. Significant spontaneous formation of biopolymers such as proteins and nucleic acids in the aqueous phase appears to be improbable due to thermodynamic constraints. It has been proposed that mineral surfaces could have served as a catalyst for the initial formation of biopolymers. However, the feasibility of this mechanism has not been thoroughly studied. In this study, a particle simulation of polypeptide formation on surfaces is developed to assess the feasibility of this mechanism. Elementary processes …
Variability Of High-Degree Modes Over Multiple Solar Cycles Using Local Helioseismic Data From Gong, Nicholas Cebula, Sushanta Tripathy, Kiran Jain, John M. Cannon
Variability Of High-Degree Modes Over Multiple Solar Cycles Using Local Helioseismic Data From Gong, Nicholas Cebula, Sushanta Tripathy, Kiran Jain, John M. Cannon
Macalester Journal of Physics and Astronomy
In this investigation we use the local helioseismic technique of ring diagrams to study the power, energy, and damping rates of high degree solar acoustic modes. Our data covers the period from the maximum phase of solar cycle 23 to the ascending phase of cycle 25. The goal is to examine the variations in the mode parameters with solar activity as well as the differences between different cycles. For this, we use different proxies of solar activity. We use 10.7 cm radio flux measurements and a measure of magnetic flux known as magnetic activity index from magnetograms.
Ammonia Emission In The Milky Way Galactic Bar Dust Lanes, Charles G. Burton
Ammonia Emission In The Milky Way Galactic Bar Dust Lanes, Charles G. Burton
Macalester Journal of Physics and Astronomy
The Central Molecular Zone (CMZ) of the Milky Way is a region of molecular gas within the inner few hundred parsecs of the Galaxy. This inner region of the Milky Way is hotter and more turbulent when compared with the disk of the Milky Way. Gas is thought to be funneled into the CMZ through dense gaseous dust lanes that are associated with the Galactic Bar. I studied two regions of one of these dust lanes using the NH3 inversion transitions of (J,K) = (1,1), (2,2), (3,3), and (4,4). Data has been obtained from the Green Bank Telescope targeting these …
Development Of A Particle-In-Cell/Monte Carlo Simulation For Weakly Ionized Plasmas, Xiaochuan (Chloe) Zheng, James Doyle
Development Of A Particle-In-Cell/Monte Carlo Simulation For Weakly Ionized Plasmas, Xiaochuan (Chloe) Zheng, James Doyle
Macalester Journal of Physics and Astronomy
A plasma is a gaseous system that contains large numbers of electrons and ions that are subject to forces produced by electric and magnetic fields. Weakly ionized plasmas, where the plasma density is much lower than the background gas density, are common in laboratory, atmospheric, and astrophysical situations. Theoretical calculations of plasma properties are challenging due to the complexity of the differential equations used to characterize fundamental physics. Particle-in-cell (PIC) simulations bypass the mathematical difficulties associated with analytic models, at the expense of more complex and time-consuming computer calculations. In this work we developed a one dimensional PIC simulation of …
Tools For Refining The Baryonic Tully-Fisher Relation, Ezra D. Wolf
Tools For Refining The Baryonic Tully-Fisher Relation, Ezra D. Wolf
Macalester Journal of Physics and Astronomy
This paper discusses the development of tools for galactic photometry using wise, and for reduction and analysis of 21cm galaxy spectra. These Python-based tools can then be applied to selected data in order to refine the Baryonic Tully-Fisher Relation. This relation, between baryonic mass and rotational velocity of a galaxy, proves useful for extragalactic research, particularly in calculating redshift-independent distances. While these tools could be further improved, they provide a robust process for calculation of particular galaxy characteristics.
Hydrosphere: Modeling The Planetary Structure Of Ocean Planets And Icy Moons, Karlee R. Taylor
Hydrosphere: Modeling The Planetary Structure Of Ocean Planets And Icy Moons, Karlee R. Taylor
Macalester Journal of Physics and Astronomy
In recent years, “water worlds” have become increasingly of interest to astrobiologists due to their high potential for habitability, as the large amount water on their surfaces is not only necessary for life, but also promises long-term climatic stability. However, also necessary for life is the exchange of chemical compounds between the geosphere and the hydrosphere - something which may be ob- structed by the presence of high pressure ices on these ocean planets and icy moons. In order to explore the habitability of bodies with various surface temperatures, water masses, and core radii, this project develops a model of …
From Experiment To Theory: Investigate The Effect Of Pump Beam Size On Photovoltaic Material Behavior, Dengyu Tu
Macalester Journal of Physics and Astronomy
In orde to investigate the effect of the pump beam size on an ultrafast conductivity measurement experiment, an experiment using Femto XL-500 laser and a simulation using Mathematica were performed. From the experiment data, we found that as the size of the pump beam decreases beyond certain limit, the Drude model can not accurately predict the relationship between conductivity and frequency. In addition, the simulation results corroborate with the experiment result that there is a limit for the size of the pump beam.
Machine Learning Refinements To Metallicity-Dependent Isotopic Abundances, Haoxuan Sun
Machine Learning Refinements To Metallicity-Dependent Isotopic Abundances, Haoxuan Sun
Macalester Journal of Physics and Astronomy
The project aims to use machine learning algorithms to fit the free parameters of an isotopic scaling model to elemental observations. The processes considered are massive star nucleosynthesis, Type Ia SNe, the s-process, the r-process, and p-isotope production. The analysis on the successful fits seeks to minimize the reduced chi squared between the model and the data. Based upon the successful refinement of the isotopic parameterized scaling model, a table providing the 287 stable isotopic abundances as a function of metallicity, separated into astrophysical processes, is useful for identifying the chemical history of them. The table provides a complete averaged …
Machine Learning Applications For Materials Science: Predicting Properties Of Two-Dimensional Magnetic Materials, Paige Stevenson
Machine Learning Applications For Materials Science: Predicting Properties Of Two-Dimensional Magnetic Materials, Paige Stevenson
Macalester Journal of Physics and Astronomy
We trained successful neural networks to predict the formation energy and magnetic moment of 2-dimensional ferromagnetic materials of similar structure to Cr2Ge2Te6. We collect elemental data on materials with known and unknown properties from easily accessible sources to screen for viable materials for use in future research. Random forest regressors were used to identify the most important predictors of our target qualities, which perform better on predictions of formation energy than magnetic moment. We predict the properties of 1225 materials that are candidates for further research in two-dimensional magnetism and identify several potential sources of error in our models that …
Fabricating Perovskite Solar Cells: Fabrication Guide For Limited Lab Capabilities, Erin F. S. Leary
Fabricating Perovskite Solar Cells: Fabrication Guide For Limited Lab Capabilities, Erin F. S. Leary
Macalester Journal of Physics and Astronomy
Within the realm of emerging photovoltaics, Perovskite cells are one of the most intriguing technologies. Within a little over a decade, Perovskite solar cells have rivaled the efficiencies of traditional silicon solar cells and strongly outpaced other emerging photovoltaic technologies. This paper aims to show a fabrication guide for creating Perovskite solar cells in a limited lab setting. The fabrication guide created structures with strong physical reliability, but limited electrical reliability. More research is needed to ensure greater reliability and proper electrical function.
Solar Radio Bursts —Deployable Low-Band Ionosphere And Transients Experiment (Dlite) Arrays, Jonathan M. Kazor, Jason Kooi
Solar Radio Bursts —Deployable Low-Band Ionosphere And Transients Experiment (Dlite) Arrays, Jonathan M. Kazor, Jason Kooi
Macalester Journal of Physics and Astronomy
Solar radio bursts, phenomenon that often accompany CME, solar flares and other solar events, can be detected on earth and used in the prediction of solar weather that affects earth systems in several ways. As part of the NREIP Program supporting the Naval Research Laboratory, Remote Sensing Division, approximately ten interns participated in the analysis of data collected by DLITE and WAVES radio data. Data from DLITE is often used as a complement to data from WAVES due to differences in frequency range and resolution. The analysis helps to correlate the DLITE data with the data collected from other sources. …
Mapping The Tesseral Field Of Saturn, Aurora Hiveley
Mapping The Tesseral Field Of Saturn, Aurora Hiveley
Macalester Journal of Physics and Astronomy
Saturn's rotation rate is still uncertain, and while it is theorized to exhibit differential rotation much like Jupiter, this claim is somewhat disputed. By analyzing the properties of waves in the ring system of Saturn as measured by the Cassini spacecraft, we aim to provide observational evidence of this phenomenon. The results of wave analysis allow us to characterize the perturbers responsible for the production of these waves, which are believed to be mass anomalies in the interior of Saturn itself. By calculating the masses of these anomalies and attempting to pinpoint their locations inside of the planet, we provide …
Trinification With A Bi-Adjoint Higgs Field, Ross Ferguson
Trinification With A Bi-Adjoint Higgs Field, Ross Ferguson
Macalester Journal of Physics and Astronomy
In this paper, we propose a novel extension of the Standard Model of particle physics, based on the trinification gauge group $SU(3)_C \times SU(3)_L \times SU(3)_R$. Symmetry breaking is achieved using a bi-adjoint Higgs field (transforming under the left- and right-handed subgroups) along with a more conventional bi-triplet to ensure the correct breaking and pattern of fermion masses. To preserve a discrete $Z_2$ symmetry (T-parity), we also introduce a right-handed triplet to completely break trinification symmetry to the Standard Model. The minimization conditions and conditions for the boundedness of the potential for this model are calculated. Additionally, the Standard Model …
Adding Classical Novae Contribution To The Isotopic Scaling Model, Mengxi Chen
Adding Classical Novae Contribution To The Isotopic Scaling Model, Mengxi Chen
Macalester Journal of Physics and Astronomy
The Isotopic Scaling model(West & Heger, 2013) provides a complete average isotopic decomposition for our Milky Way as a function of metallicity and it requires an initial Solar Abundance Decomposition as a starting point. The previous Solar Abundance decomposition work is not perfect(West & Heger, 2013), since Classical Novae abundances are ignored. My research intends to improve the current solar abundance decomposition by adding Classical Novae Abundance contribution, then to update the Isotopic Scaling model.
Twisting Lasers With The Faraday Effect, Harrison Werrell
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
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
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
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
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 …