Physical Sciences and Mathematics Commons^™

Analysis On High Mass X-Ray Binary Spectral Shape Dependence On Luminosity For Ngc3310, Izabela Pavel

Physics Undergraduate Honors Theses

In most normal galaxies, the most X-ray luminous sources are high-mass X-ray binaries (HMXBs), which are binary star systems that contain compact objects (black holes or neutron stars) accreting from massive (> 8M⊙) companion stars. These HMXBs are thought to have been important sources of ionizing emission within star-forming galaxies that may have contributed to the heating of the intergalatic medium (gas over large cosmic scales) in the early Universe. When studying how HMXBs contribute to interstellar medium feedback, a single spectral shape of an absorbed power-law is typically assumed to be universal. The goal of this thesis is to …

Mach And Froude Numbers On Mars., Camella-Rosa Nasr

Electronic Theses and Dissertations

Mars atmospheric global circulation models exhibit transonic jet streaks during
northern winter, which motivates this study of the Mach number, Ma (the ratio of
flow speed to the speed of sound), and the Froude number, Fr (the ratio of flow
speed to the speed of buoyancy waves), as a function of season and location. Two
global reanalyses spanning Mars Years (MY) 24 to 33 are used as input, EMARS
and OpenMARS. The study’s vertical coordinate is the isentropic variable potential
temperature, θ, ranging from θ = 125 to 1100 K, which corresponds to altitudes
ranging on average from z ≈ …

Numerical Simulations Of Tidal Disruption Events, Alexandra Elise Spaulding

Theses and Dissertations

The detection of supermassive black holes (SMBH) in our universe has proven to be a challenge. One way to find an SMBH in a quiescent, inactive galaxy is through a tidal disruption event, or a TDE. A TDE occurs when a star is slightly perturbed and is subsequently disrupted by the SMBH. When this happens, part of the debris from the disrupted star remains bound to the SMBH while the rest is unbound. The SMBH accretes the bound matter and reveals their presence by a temporary X-ray flare, lasting a few months. Using conservation of energy, the fallback rate of …

Evaluation Of Black Holes In An Evolving Universe, John P. Naan

Theses and Dissertations

There are various solutions to the Einstein field equations that represent different physical assumptions, but how to represent multiple black holes within an expanding universe remains an area of open interest. The first step to resolving this question involves evaluating spacetime models that contain a single black hole in an expanding universe. Here, we are primarily interested in understanding the energy distribution of black hole models by solving Einstein's equations using the associated spacetime metric and comparing the propagation of waves within the model against other known spacetime models. Specifically, we will evaluate the combined Schwarschild-de Sitter solution under a …

Insights Into Star Formation And Agn Activity In Protocluster Environments From Morphological Studies And Sed Fitting, Erik B. Monson

Graduate Theses and Dissertations

In this dissertation I present work done from 2018-2023 to investigate the growth of galaxies and supermassive black holes (SMBH) in high redshift overdensities (protoclusters) by studying the star-forming galaxy and active galactic nucleus (AGN) population in the SSA22 protocluster. I examined possible environmental sources of the enhanced star formation and AGN activity in the z = 3.09 SSA22 protocluster using Hubble WFC3 ∼ 1.6 μm observations of the SSA22 field, including new observations centered on eight X-ray selected protocluster AGN. To investigate the role of mergers in the observed AGN and star formation enhancement, quantitative and visual morphological classifications …

On The Impact Of Inclination-Dependent Attenuation On The Derived Star Formation Histories Of Disk Galaxies, Keith Doore

Graduate Theses and Dissertations

The physical properties of a galaxy (e.g., its star-formation history and dust content) regulate the distribution of light that is emitted by stars and attenuated by the interstellar gas and dust. This attenuation by dust can have a significant impact on the observed spectral energy distribution (SED) of a disk galaxy, especially when taking into account its viewing angle (i.e., inclination). For example, as the inclination angle of a galactic disk changes from face-on to edge-on (i.e., i = 0 deg to i = 90 deg), the proportion of light that is attenuated along the line of sight increases, due …

A Comparison Of Automated Bolide Detection Methods, Maxine Thembi Khumalo

Theses and Dissertations

Bolide recording and analysis are crucial so meteoroid fragments can be found, a lightcurve analyzed, and its trajectory calculated. The Spalding Allsky Camera Network (SACN) generates videos and composite images of the night sky that are potential meteors based on changes in brightness. The best way to ensure quick identification is to automate the detection of bolides (and all meteors) using computational techniques. This project tested three algorithms to sort events between those with and without meteors - a Traditional Hough Detection Method, Convolutional Neural Network (CNN), and YOLOv5 against the previous technique from 2018 by Elena Botella. All the …

The Response Of Atomic-To-Molecular Hydrogen Transition Points In Photodissociation Regions Due To A Hard X-Ray Spectrum, Gregory Joseph Colarch

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation develops a model for the response of the transition points in the density profiles from atomic (H0) to molecular (H2) hydrogen in a photodissociation region (PDR) due to a hard X-ray flux (HXR). A model for a steady-state PDR due to the photodissociation of H2 by the far-ultraviolet (FUV) Lyman-Werner radiation band is presented both analytically and computa- tionally. A steady state X-ray dissociation region (XDR) from an HXR in the 1 - 100 keV energy range is also developed both analytically and computationally. An analytic model is then developed by combining these two different steady state models. …

Inferring The Compositions And Interior Structures Of Small Planets, David R. Rice

UNLV Theses, Dissertations, Professional Papers, and Capstones

Although there are now over 10,000 confirmed and candidate extrasolar planets, accurate masses and radii have been determined for around 200 planets of less than 10 Earth-masses. This number will grow exponentially over the next decade as extreme precision radial velocity spectrographs see first light. The densities of small planets hint at a diverse range of compositions for terrestrial worlds from super-Mercuries to super-Ganymedes. Uncertainty in density is as low as 3% in the Trappist-1 system. To determine composition from observed parameters, the community uses a variety of interior structure models. Underlying these models are multiple computational techniques, numerous experimental …

Exploring The Dependence Of Bulges In Spiral Galaxies On Their Environment, William Jackson Clark

Physics Theses & Dissertations

Recent research has shown a relationship between spiral galaxy satellite populations and the size of spiral bulges. The modern cosmological model of our universe (ΛCDM), does not predict this. Instead, ΛCMD predicts that only the total dynamical mass of a host galaxy should be correlated with satellite populations. We investigate this relationship in regimes other than satellites. In this study we compare the bulge to total mass ratios of spiral galaxies to the number of nearby galaxies within “n” Mpc. We use four papers from literature that calculate bulge to total mass ratios of 189 spiral galaxies using …

Constraining H0 Via Extragalactic Parallax, Nicholas Ferree

Honors Theses

We examine the prospects for measurement of the Hubble parameter 𝐻₀ via observation of the secular parallax of other galaxies due to our own motion relative to the cosmic microwave background rest frame. Peculiar velocities make distance measurements to individual galaxies highly uncertain, but a survey sampling many galaxies can still yield a precise 𝐻₀ measurement. We use both a Fisher information formalism and simulations to forecast errors in 𝐻₀ from such surveys, marginalizing over the unknown peculiar velocities. The optimum survey observes ∼ 102 galaxies within a redshift 𝐻₀max = 0.06. The required errors …

Optimizing A Passive Tracking Solar Panel System, Carsten Johnson

Scholars Day Conference

Renewable energy has been gaining attention from individuals to government agencies as the negative effects of fossil fuel usage has been realized. Solar power is a reliable and green alternative to fossil fuels. Solar power is harnessed through the direct absorption of rays from the sun. In this experiment, a passive sun-tracking system using a shape memory alloy (SMA), gears, and a fresnel lens rotated a solar panel to face the sun throughout the day. At the end of the day the system rotates the solar panel back to the east in preparation for the next day’s cycle to begin. …

Characterization Of Extended Uncertainty Principle Black Holes, Juan Uribe, Jonas Mureika

Honors Thesis

Black Holes are special objects as they are at the intersection of Quantum Mechanics and General Relativity. A central tenant of quantum mechanics is the Uncertainty Principle that dictates we cannot know with complete certainty position and momentum at the same time. The Extended Uncertainty Principle introduces a position-related uncertainty correction L_* to account for General Relativity. In a previous paper, a black hole metric associated with the Extended Uncertainty Principle was derived, by modifying the metric function of a Schwarzschild black hole. This metric introduces near-horizon structures that should produce observable effects, such as love numbers, gravitational wave echoes, …

The Magnetic Field Of Protostar-Disk-Outflow Systems, Mahmoud Sharkawi

Electronic Thesis and Dissertation Repository

Recent observations of protostellar cores reveal complex magnetic field configurations that are distorted in the innermost disk region. Unlike the prestellar phase, where the magnetic field geometry is simpler with an hourglass configuration, magnetic fields in the protostellar phase are sculpted by the formation of outflows and rapid rotation. This gives rise to a significant azimuthal (or toroidal) component that has not yet been analytically modelled in the literature. Moreover, the onset of outflows, which act as angular momentum transport mechanisms, have received considerable attention in the past few decades. Two mechanisms: 1) the driving by the gradient of a …

The Rotational Period Distribution Of Massive Magnetic White Dwarfs, Zorayda Martinez

Honors Theses

Rapidly rotating white dwarfs (WDs) have the potential to come about by either double degenerate mergers or weak coupling between the core and the outer envelope during the asymptotic giant branch (AGB). For both cases, knowledge of the rotational period distribution places tight constraints on the evolution of angular momentum transfer. Here we present initial results from a study of the rotational period distribution of 19 massive (M > 0:9M), magnetic, DA WDs observed by the Transiting Exoplanet Survey Satellite (TESS) and 17 observed with ground-based telescopes and analyzed with the Lightkurve python package. We present periodograms, folded light curves, and …

New Physics In The Age Of Precision Cosmology, Vivian I. Sabla

Dartmouth College Ph.D Dissertations

The Lambda-cold dark matter (LCDM) model has become the standard model of cosmology because of its ability to reproduce a vast array of cosmological observations, from the earliest moments of our Universe, to the current period of accelerated expansion, which it does with great accuracy. However, the success of this model only distracts from its inherent flaws and ambiguities. LCDM is purely phenomenological, providing no physical explanation for the nature of dark matter, responsible for the formation and evolution of large-scale structure, and giving an inconclusive explanation for dark energy, which drives the current period of accelerated expansion.

Furthermore, cracks …

Optimal Method For Reconstructing Polychromatic Maps From Broadband Observations With An Aysmmetric Antenna Pattern, Brianna Cantrall, Emory F. Bunn, Solomon Quinn

Honors Theses

Broadband time-ordered data obtained from telescopes with a wavelength-dependent, asymmetric beam pattern can be used to extract maps at multiple wavelengths from a single scan. This technique is especially useful when collecting data on cosmic phenomena such as the Cosmic Microwave Background (CMB) radiation, as it provides the ability to separate the CMB signal from foreground contaminants. We develop a method to determine the optimal linear combinations of wavelengths (“colors”) that can be reconstructed for a given telescope design and the number of colors that are measurable with high signal-to-noise ratio. The optimal colors are found as eigenvectors of a …

Applying Bioactive Glass Beads For Long-Term Drug Delivery, Marie O. Sykes, Rashi Sharma

Physics and Astronomy Presentations

Bioactive glass beads have been used to distribute medicine over extended periods of time in limited uses. They can be engineered to have a porous and hollow structure, and using Mo-Sci's OL-GL 1756b (1756b), the fundamental notion of dosage distribution can be tested in preparation to design the optimal glass for medicine distribution. A few key factors in this is how long does it take the liquid to release from the beads, how do the beads decay, and how well the glass can bond to human tissue. This research demonstrates the capacities of the 1756b type as a promising start …

Paul Feder Observatory Upgrades And Exoplanet And Variable Star Data, Mara Derung, Tanner Weyer, Emily Watson

Student Academic Conference

Before the upgrade to the dome and telescope, much of the work to use the telescope was done manually. One had to drive an hour round trip to the observatory at dusk and dawn to ensure that the telescope started up and shutdown properly. Proper startup included manually opening the lower dome flap via hand crank and briefly plugging in the top part of the dome to raise the upper slit. Shutting down the telescope during the summer required a person to be at the telescope by 5:00AM, before sunrise to make sure that the dome closed before the sun …

Identifying Gravity Waves Launched By The Hunga Tonga–Hunga Ha’Apai Volcanic Eruption In Mesosphere/Lower-Thermosphere Winds Derived From Condor And The Nordic Meteor Radar Cluster, Gunter Stober, Alan Liu, Alexander Kozlovsky, Zishun Qiao, Witali Krochin, Guochun Shi, Johan Kero, Et Al.

Publications

The Hunga Tonga–Hunga Ha'apai volcano eruption was a unique event that caused many atmospheric phenomena around the globe. In this study, we investigate the atmospheric gravity waves in the mesosphere/lower thermosphere (MLT) launched by the volcanic explosion in the Pacific, leveraging multistatic meteor radar observations from the Chilean Observation Network De Meteor Radars (CONDOR) and the Nordic Meteor Radar Cluster in Fennoscandia. MLT winds are computed using a recently developed 3DVAR+DIV algorithm. We found eastward- and westward-traveling gravity waves in the CONDOR zonal and meridional wind measurements, which arrived 12 and 48 h after the eruption, and we found one …

Lesson Plans In Astronomy, Ecology And Biology, Admin Stem For Success

STEM for Success Showcase

This document contains various lesson plan ideas for concepts within the fields of biology, ecology, astronomy, and geology.

Information Horizon Of Solar Active Regions, Jay R. Johnson, Simon Wing, Carson O'Ffill, Bishwa Neupane

Faculty Publications

Information theory is used to characterize the solar active region periodicities and memories from the Carrington map images 1974–2021. The active regions typically evolve and move from one map to the next. In order to track these active region structures in sequences of images, an innovative method based on information theory is developed. Image entropy provides a measure of the organization of structures in the images. The entropy can also be used as a filter to identify structures and partition the active regions, which are then registered for each image. The partitions are used to compute the mutual information and …

Non-Hermitian Edge Burst Without Skin Localization, Cem Yuce, Hamidreza Ramezani

Physics and Astronomy Faculty Publications and Presentations

In a class of non-Hermitian quantum walk in lossy lattices with open boundary conditions, an unexpected peak in the distribution of the decay probabilities appears at the edge, referred to as an edge burst. It is proposed that the edge burst originates jointly from the non-Hermitian skin effect (NHSE) and the imaginary gaplessness of the spectrum [W.-T. Xue et al., Phys. Rev. Lett. 128, 120401 (2022)]. Using a particular one-dimensional lossy lattice with a nonuniform loss rate, we show that the edge burst can occur even in the absence of skin localizations. Furthermore, we discuss that the edge …

Membership Probabilities Of White Dwarfs In Open Star Clusters, Sarah Phillips

Honors Theses

This thesis explores the relationship between astronomical position data and star cluster membership. Our research project focuses on the mathematical probability of cluster membership for white dwarf stars (WDs), specifically membership candidates within the open cluster Messier 35. Through Gaussian analysis of proper motion data, we examine the membership probability of each candidate. Establishing cluster membership has broad applications and can allow further determination of a star’s characteristics including stellar age and evolution. Of particular interest are two WD member candidates for Messier 35: LAWDS 4, a DB WD with a helium-dominated atmosphere as opposed to the more common hydrogen-dominated …

Wallaby Pre-Pilot Survey: Radio Continuum Properties Of The Eridanus Supergroup, J. A. Grundy, O. I. Wong, K. Lee-Waddell, N. Seymour, B. -Q. For, C. Murugeshan, B. S. Koribalski, Juan P. Madrid, J. Rhee, T. Westmeier

Physics and Astronomy Faculty Publications and Presentations

We present the highest resolution and sensitivity ∼ 1.4 GHz continuum observations of the Eridanus supergroup obtained as a part of the Widefield Australian Square Kilometer Array Pathfinder (ASKAP) L-band Legacy All-sky Blind surveY (WALLABY) pre-pilot observations using the ASKAP. We detect 9461 sources at 1.37 GHz down to a flux density limit of ∼ 0.1 mJy at 6.1′′×7.9′′ resolution with a median root mean square of 0.05 mJy beam −1 . We find that the flux scale is accurate to within 5 % (compared to NVSS at 1.4 GHz). We then determine the global properties of eight Eridanus supergroup …

Analog Cosmology And Superfluidity In Atomic Gases And Electronic Materials, Anshuman Bhardwaj

LSU Doctoral Dissertations

We present a study of analog cosmological models in Bose-Einstein condensates (BEC) and in graphene, and superfluidity in a box-shaped traps. We start by examining the dynamics of a Bose-Einstein condensate (BEC) trapped inside an expanding toroid that can realize an analog inflationary universe. The expanding condensate forces phonons to undergo redshift and damping due to quantum pressure, owing to the thinness of the ring. We predict that such expanding BECs can exhibit spontaneous phonon creation from the vacuum state and show how it would manifest in the atom density and density correlations and discuss connections with the inflationary theory. …

Evaluating Neutron Star Binding Energies Using Rotating Accreting Models, Nathan Moore

Honors Theses

Neutron star binding energy increases due to accreting matter from neighboring astronomical bodies, and decreases due to the star spinning up, increasing its angular velocity. We present a novel set of models that account for both increasing angular velocity and accreting matter to track a neutron star’s evolution. We arrive at these models through studying and reconfiguring computational investigations from the past, particularly a code which generates a model for a given fixed baryon mass and angular velocity and another that takes it from one baryon mass and angular velocity to the next one through accretion, to obtain a full …

The Role Of Volatile Enrichment In The Radiogenic Heating And Thermal Evolution Of Rocky Exoplanets, Ula Jones, Asmaa Boujibar

WWU Honors College Senior Projects

Internal heating in terrestrial planets is a fundamental physical process controlling the internal structure of a planet, mantle convection, volcanic activity, and the generation of magnetic fields. Internal heating results from various processes including radioactive decay and accretional energy, as well as additional irradiation and tidal heating in planets with short orbital periods. The largest long-term heat source for terrestrial planets is radioactive heating, especially from the decay of uranium (U), thorium (Th), and potassium (K) isotopes. K is a moderately volatile element, while U and Th are refractory elements; during planetary accretion volatiles are depleted relative to refractory elements, …

Toi-836: A Super-Earth And Mini-Neptune Transiting A Nearby K-Dwarf, F. Hawthorn, D. Bayliss, T. G. Wilson, A. Bonfanti, V. Adibekyan, Y. Alibert, S. G. Sousa, K. A. Collins, E. M. Bryant, A. Osborn, D. J. Armstrong, L. Abe, J. S. Acton, B. C. Addison, K. Agabi, R. Alonso, D. R. Alves, G. Anglada-Escudé, T. Bárczy, T. Barclay, D. Barrado, S. C. C. Barros, W. Baumjohann, P. Bendjoya, W. Benz, A. Bieryla, X. Bonfils, F. Bouchy, A. Brandeker, C. Broeg, D. J. A. Brown, M. R. Burleigh, M. Buttu, J. Cabrera, D. A. Caldwell, S. L. Casewell, D. Charbonneau, S. Charnoz, R. Cloutier, A. Collier Cameron, K. I. Collins, D. M. Conti, N. Crouzet, S. Czismadia, M. B. Davies, M. Deleuil, E. Delgado-Mena, L. Delrez, O. D. S. Demangeon, B.-O. Demoray, G. Dransfield, X. Dumusque, J. A. Egger, D. Ehrenreich, P. Eigmüller, A. Erickson, Z. Essack, A. Fortier, L. Fossati, M. Fridlund, M. N. Günther, M. Güdel, D. Gandolfi, H. Gillard, M. Gillon, C. Gnilka, M. R. Goad, R. F. Goeke, T. Guillot, A. Hadjigeorghiou, C. Hellier, B. A. Henderson, K. Heng, M. J. Hooton, K. Horne, S. B. Howell, S. Hoyer, J. M. Irwin, J. S. Jenkins, J. M. Jenkins, Eric L.N. Jensen, S. R. Kane, A. Kendall, J. F. Kielkopf, L. L. Kiss, G. Lacedelli, J. Laskar, D. W. Latham, A. Lecavalier Des Etangs, A. Leleu, M. Lendl, J. Lillo-Box, C. Lovis, D. Mékarnia, B. Massey, T. Masters, P. F. L. Maxted, V. Nascimbeni, L. D. Nielsen, S. M. O'Brien, G. Olofsson, H. P. Osborn, I. Pagano, E. Pallé, C. M. Persson, G. Piotto, P. Plavchan, D. Pollacco, D. Queloz, R. Ragazzoni, H. Rauer, I. Ribas, G. Ricker, D. Ségransan, S. Salmon, A. Santerne, N. C. Santos, G. Scandariato, F.-X. Schmider, R. P. Schwarz, S. Seager, A. Shporer, A. E. Simon, A. M. S. Smith, G. Srdoc, M. Steller, O. Suarez, G. M. Szabó, J. Teske, N. Thomas, R. H. Tilbrook, A. H. M. J. Triaud, S. Udry, V. Van Grootel, N. Walton, S. X. Wang, P. J. Wheatley, J. N. Winn, R. A. Wittenmyer, H. Zhang

Physics & Astronomy Faculty Works

We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright (T = 8.5 mag), high proper motion (∼200 mas yr⁻¹), low metallicity ([Fe/H]≈−0.28) K-dwarf with a mass of 0.68 ± 0.05 M_⊙ and a radius of 0.67 ± 0.01 R⊙. We obtain photometric follow-up observations with a variety of facilities, and we use these data sets to determine that the inner planet, TOI-836 b, is a 1.70 ± 0.07 R_⊕ super-Earth in a 3.82-d orbit, placing it directly within the so-called …

The Extremes Of Galaxy Formation & Evolution, Kelly E. Whalen

Dartmouth College Ph.D Dissertations

Galaxy populations are shaped by the physical processes that regulate their star formation and central black hole growth throughout cosmic time. The primary aim of this thesis is to understand how these processes occur and how they shape evolution in some of the most extreme galaxies in the Universe including quasars, compact starbursts, and ultra-diffuse dwarfs. Gas-rich major mergers funnel large amounts of gas towards the nucleus, triggering rapid AGN accretion and compact star formation. In this work, I study powerful quasars and extreme, massive, compact starburst galaxies within the context of merger-driven galaxy evolution scenarios. One aim of this …