Information Horizon Of Solar Active Regions,
2023
Andrews University
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,
2023
The University of Texas Rio Grande Valley
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,
2023
Texas A&M University-Commerce
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,
2023
The University of Texas Rio Grande Valley
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 …
Dissecting The Most Extreme Starburst Events In The Universe With Gravitational Lensing,
2023
University of Massachusetts Amherst
Dissecting The Most Extreme Starburst Events In The Universe With Gravitational Lensing, Patrick S. Kamienski
Doctoral Dissertations
Three billions years after the Big Bang, the rate at which galaxies in the Universe were forming stars was at its peak. Colloquially known as Cosmic Noon, this epoch (redshift z ~ 2) is crucial to our understanding of how galaxies evolve with time. Dusty star-forming galaxies (DSFGs) offer important clues to such fueling and quenching of star formation. With extreme infrared luminosities (1012 − 1014 solar luminosities), their inferred star formation rates are 100−10000 solar masses per year. Yet, the physical mechanisms by which they fuel this short-lived maximal starburst phase remain poorly understood. With this dissertation, …
The Extremes Of Galaxy Formation & Evolution,
2023
Dartmouth College
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 …
Evaluating Neutron Star Binding Energies Using Rotating Accreting Models,
2023
Texas A&M University-Commerce
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 …
Galaxy And Mass Assembly (Gama): Low-Redshift Quasars And Inactive Galaxies Have Similar Neighbors,
2023
University of Louisville
Galaxy And Mass Assembly (Gama): Low-Redshift Quasars And Inactive Galaxies Have Similar Neighbors, Maria B. Stone, Clare F. Wethers, Roberto De Propris, Jari Kotilainen, Nischal Acharya, Benne W. Holwerda, Jonathan Loveday, Steven Phillipps
Faculty Scholarship
We explore the properties of galaxies in the proximity (within a ∼2 Mpc radius sphere) of Type I quasars at 0.1 <z <0.35, to check whether and how an active galaxy influences the properties of its neighbors. We further compare these with the properties of neighbors around inactive galaxies of the same mass and redshift within the same volume of space, using the Galaxy and Mass Assembly spectroscopic survey. Our observations reveal no significant difference in properties such as the number of neighbors, morphologies, stellar mass, star formation rates, and star formation history between the neighbors of quasars and those of the comparison sample. This implies that quasar activity in a host galaxy does not significantly affect its neighbors (e.g., via interactions with the jets). Our results suggest that quasar host galaxies do not strongly differ from the average galaxy within the specified mass and redshift range. Additionally, the implication of the relatively minor importance of the environmental effect on and from quasars is that nuclear activity is more likely triggered by internal and secular processes.
The Role Of Volatile Enrichment In The Radiogenic Heating And Thermal Evolution Of Rocky Exoplanets,
2023
Western Washington University
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, …
Jwst’S Pearls: Dust Attenuation And Gravitational Lensing In The Backlit-Galaxy System Vv 191,
2023
University of Louisville
Jwst’S Pearls: Dust Attenuation And Gravitational Lensing In The Backlit-Galaxy System Vv 191, William C. Keel, Rogier A. Windhorst, Rolf A. Jansen, Seth H. Cohen, Jake Summers, Benne Holwerda, Sarah T. Bradford, Clayton D. Robertson, Giovanni Ferrami, Stuart Wyithe, Haojing Yan, Christopher J. Conselice, Simon P. Driver, Aaron Robotham, Norman A. Grogin, Christopher N. A. Willmer, Anton M. Koekemoer, Brenda L. Frye, Nimish P. Hathi, Russell E. Ryan Jr., Nor Pirzkal, Madeline A. Marshall, Dan Coe, Jose M. Diego, Thomas J. Broadhurst, Michael J. Rutkowski, Lifan Wang, S. P. Willner, Andreea Petric, Cheng Cheng, Adi Zitrin
Faculty Scholarship
We present the first JWST observations of the z = 4.11 luminous radio galaxy TN J1338–1942, obtained as part of the ‘Prime Extragalactic Areas for Reionization and Lensing Science’ (‘PEARLS’) project. Our NIRCam observations, designed to probe the key rest-frame optical continuum and emission line features at this redshift, enable resolved spectral energy distribution modelling that incorporates both a range of stellar population assumptions and radiative shock models. With an estimated stellar mass of log10(M/M⊙) ∼ 10.9, TN J1338–1942 is confirmed to be one of the most massive galaxies known at this epoch. Our observations also reveal extremely high equivalent-width …
Toi-836: A Super-Earth And Mini-Neptune Transiting A Nearby K-Dwarf,
2023
Swarthmore College
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 …
Euler And Venus' Suspicious Moon,
2023
St. Edward's University
Euler And Venus' Suspicious Moon, Michael P. Saclolo
Euleriana
This is a brief note on Leonhard Euler's published German translation from the French of two memoirs read by Armand Henri Baudouin de Guémadeuc to the Paris Academy of Sciences in 1761 and published the same year. The memoirs report on observations made of the planet Venus, performed in Limoges, France by Jacques Montaigne, where he claimed to have detected a moon orbiting the Morning and Evening Star.
Population Of Merging Compact Binaries Inferred Using Gravitational Waves Through Gwtc-3,
2023
The University of Texas Rio Grande Valley
Population Of Merging Compact Binaries Inferred Using Gravitational Waves Through Gwtc-3, R. Abbott, T. Abbott, F. Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Volker Quetschke, Wen Hui Wang
Physics and Astronomy Faculty Publications and Presentations
We report on the population properties of compact binary mergers inferred from gravitational-wave observations of these systems during the first three LIGO-Virgo observing runs. The Gravitational-Wave Transient Catalog 3 (GWTC-3) contains signals consistent with three classes of binary mergers: binary black hole, binary neutron star, and neutron star–black hole mergers. We infer the binary neutron star merger rate to be between 10 and 1700 Gpc−3 yr−1 and the neutron star–black hole merger rate to be between 7.8 and 140 Gpc−3 yr−1, assuming a constant rate density in the comoving frame and taking the union of 90% credible intervals for methods …
Transport Effects In Non-Hermitian Nonreciprocal Systems: General Approach,
2023
The University of Texas Rio Grande Valley
Transport Effects In Non-Hermitian Nonreciprocal Systems: General Approach, Hamed Ghaemi-Dizicheh
Physics and Astronomy Faculty Publications and Presentations
In this paper, we present a unifying analytical framework for identifying conditions for transport effects such as reflectionless and transparent transport, lasing, and coherent perfect absorption in non-Hermitian nonreciprocal systems using a generalized transfer matrix method. This provides a universal approach to studying the transport of tight-binding platforms, including higher-dimensional models and those with an internal degree of freedom going beyond the previously studied case of one-dimensional chains with nearest-neighbor couplings. For a specific class of tight-binding models, the relevant transport conditions and their signatures of non-Hermitian, nonreciprocal, and topological behavior are analytically tractable from a general perspective. We investigate …
Off-Shell Effects In Bound Nucleons And Parton Distributions From 1H, 2H, 3H, And 3He Data,
2023
University of South Carolina
Off-Shell Effects In Bound Nucleons And Parton Distributions From 1H, 2H, 3H, And 3He Data, S. I. Alekhin, S. A. Kulagin, Roberto Petti
Faculty Publications
We report the results of a new global QCD analysis including deep-inelastic scattering data off 1H, 2H, 3H, and 3He targets. Nuclear corrections are treated in terms of a nuclear convolution approach with off-shell bound nucleons. The off-shell (OS) corrections responsible for the modification of the structure functions (SFs) of bound nucleons are constrained in a global fit along with the proton parton distribution functions (PDFs) and the higher-twist (HT) terms. We investigate the proton-neutron difference for the OS correction and discuss our predictions for the SF ratio F n 2 / F p 2 and …
Measurement Of The Double-Differential Muon-Neutrino Charged-Current Inclusive Cross Section In The Nova Near Detector,
2023
University of South Carolina
Measurement Of The Double-Differential Muon-Neutrino Charged-Current Inclusive Cross Section In The Nova Near Detector, M. A. Acero, P. Adamson, L. Aliaga, N. Anfimov, A. Antoshkin, E. Arrieta-Diaz, L. Asquith, A. Aurisano, A. Back, M. Baird, N. Balashov, P. Baldi, B. A. Bambah, S. Bashar, K. Bays, B. Behera, R. Bernstein, V. Bhatnagar, D. Bhattarai, B. Bhuyan, Roberto Petti, Et. Al.
Faculty Publications
We report cross-section measurements of the final-state muon kinematics for νμ charged-current interactions in the NOvA near detector using an accumulated 8.09×1020 protons on target in the NuMI beam. We present the results as a double-differential cross section in the observed outgoing muon energy and angle, as well as single-differential cross sections in the derived neutrino energy, Eν, and square of the four-momentum transfer, Q2. We compare the results to inclusive cross-section predictions from various neutrino event generators via χ2 calculations using a covariance matrix that accounts for bin-to-bin correlations of systematic uncertainties. …
The Quantitative Microanalysis Explorer: Introducing Web-Based Visualization For Optical, Electron, And Quantitative X-Ray Maps For Studying Lunar Samples,
2023
Washington University in St. Louis
The Quantitative Microanalysis Explorer: Introducing Web-Based Visualization For Optical, Electron, And Quantitative X-Ray Maps For Studying Lunar Samples, Angelina Minocha
Senior Honors Papers / Undergraduate Theses
Modern sample imaging techniques produce data in the form of large mosaics, wherein every pixel contains valuable mineralogical information. These heavy data files are challenging for most computers to load and process, furthermore access to lunar and other extraterrestrial samples is limited. We developed the QME Tool to display optical, electron, and quantitative x-ray maps in conjunction with one another to overcome these challenges and advance mineralogy data presentation and analysis. The images and quantitative data was collected using specialized techniques, followed by an extensive image co-registration process. The interface was developed using OpenSeadragon, “An open-source, web-based viewer for high-resolution …
Stellar Binaries And Post-Merger Evolution: A Framework For Stellar Evolution And Nucleosynthesis In R Coronae Borealis Stars,
2023
Louisiana State University and Agricultural and Mechanical College
Stellar Binaries And Post-Merger Evolution: A Framework For Stellar Evolution And Nucleosynthesis In R Coronae Borealis Stars, Bradley Munson
LSU Doctoral Dissertations
We have developed a framework for simulating binary stars through all three relevant
timescales: the dynamical merger, thermal, and nuclear evolution. The framework begins by simulating a dynamical merger in a 3-dimensional hydrodynamics adaptive mesh refinement code, Octo-Tiger, and performing a spherical averaging calculation to map the post-merger remnant into the 1-dimensional stellar evolution code, MESA. In this work, we primarily utilize this framework for simulating double white dwarf mergers, which are believed to be the progenitor to R Coronae Borealis (RCB) stars. We evolve the post-merger in MESA and compare the computed surface abundances to those observed …
Powerful Radio Sources In The Southern Sky. I. Optical Identifications,
2023
The University of Texas Rio Grande Valley
Powerful Radio Sources In The Southern Sky. I. Optical Identifications, Francesco Massaro, S. V. White, A. García-Pérez, A. Jimenez-Gallardo, A. Capetti, C. C. Cheung, W. R. Forman, C. Mazzucchelli, A. Paggi, Juan P. Madrid
Physics and Astronomy Faculty Publications and Presentations
Since the early sixties, our view of radio galaxies and quasars has been drastically shaped by discoveries made thanks to observations of radio sources listed in the Third Cambridge Catalog and its revised version (3CR). However, the largest fraction of data collected to date on 3CR sources was performed with relatively old instruments, rarely repeated and/or updated. Importantly, the 3CR contains only objects located in the Northern Hemisphere, thus having limited access to new and innovative astronomical facilities. To mitigate these limitations, we present a new catalog of powerful radio sources visible from the Southern Hemisphere, extracted from the GLEAM …
A Candidate Magnetic Helium-Core White Dwarf In The Globular Cluster Ngc 6397,
2023
The University of Texas Rio Grande Valley
A Candidate Magnetic Helium-Core White Dwarf In The Globular Cluster Ngc 6397, Manuel Pichardo Marcano, Liliana E. Rivera Sandoval, Thomas J. Maccarone, Rene D. Rohrmann, Craig O. Heinke, Diogo Belloni, Leandro G. Althaus, Arash Bahramian
Physics and Astronomy Faculty Publications and Presentations
We report a peculiar variable blue star in the globular cluster (GC) NGC 6397, using Hubble Space Telescope optical imaging. Its position in the colour–magnitude diagrams and its spectrum are consistent with this star being a helium-core white dwarf (He WD) in a binary system. The optical light curve shows a periodicity at 18.5 h. We argue that this periodicity is due to the rotation of the WD and possibly due to magnetic spots on the surface of the WD. This would make this object the first candidate magnetic He WD in any GC, and the first candidate magnetic WD …
