Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy Commons

Open Access. Powered by Scholars. Published by Universities.®

9,564 Full-Text Articles 25,255 Authors 1,367,047 Downloads 213 Institutions

All Articles in Astrophysics and Astronomy

Faceted Search

9,564 full-text articles. Page 3 of 313.

Glitch Veto Based On Unphysical Gravitational Wave Binary Inspiral Templates, Raghav Girgaonkar, Soumya D. Mohanty 2024 The University of Texas Rio Grande Valley

Glitch Veto Based On Unphysical Gravitational Wave Binary Inspiral Templates, Raghav Girgaonkar, Soumya D. Mohanty

Physics and Astronomy Faculty Publications and Presentations

Transient signals arising from instrumental or environmental factors, commonly referred to as glitches, constitute the predominant background of false alarms in the detection of gravitational waves in data collected from ground-based detectors. Therefore, effective data analysis methods for vetoing glitch-induced false alarms are crucial to enhancing the sensitivity of a search for gravitational waves. We present a veto method for glitches that impact matched filtering-based searches for binary inspiral signals. The veto uses unphysical sectors in the space of chirp time parameters as well as an unphysical extension including negative chirp times to efficiently segregate glitches from gravitational wave signals …


Ultralight Vector Dark Matter Search Using Data From The Kagra O3gk Run, A. Abac, R. Abbott, H. Abe, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang 2024 The University of Texas Rio Grande Valley

Ultralight Vector Dark Matter Search Using Data From The Kagra O3gk Run, A. Abac, R. Abbott, H. Abe, Teviet Creighton, Mario C. Diaz, Francisco Llamas, Soma Mukherjee, Gaukhar Nurbek, Volker Quetschke, Wenhui Wang

Physics and Astronomy Faculty Publications and Presentations

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the …


Ratification Of The Base Of The Ics Geological Time Scale: The Global Standard Stratigraphic Age (Gssa) For The Hadean Lower Boundary, Janna Halla, Nora Noffke, Humberto Reis, Stanley Awramik, Andrey Bekker, Alexander Brasier, Flávia Callefo, Adrita Choudhury, Jan-Peter Duda, Christopher Fedo, Douglas Galante, Jessica Haddock, Peter Haines, Linda Hinnov, Axel Hofmann, Martin Homann, David Huston, Simon Johnson, Linda Kah, Martin Whitehouse, et al. 2024 Finnish Museum of Natural History

Ratification Of The Base Of The Ics Geological Time Scale: The Global Standard Stratigraphic Age (Gssa) For The Hadean Lower Boundary, Janna Halla, Nora Noffke, Humberto Reis, Stanley Awramik, Andrey Bekker, Alexander Brasier, Flávia Callefo, Adrita Choudhury, Jan-Peter Duda, Christopher Fedo, Douglas Galante, Jessica Haddock, Peter Haines, Linda Hinnov, Axel Hofmann, Martin Homann, David Huston, Simon Johnson, Linda Kah, Martin Whitehouse, Et Al.

OES Faculty Publications

The base of the ICS (International Commission on Stratigraphy) Geological Time Scale was ratified in 2022 by defining a new Global Stratigraphic Standard Age (GSSA) for the lower boundary of the Hadean Eon (formerly 4000-3600 Ma); the age of the Solar System based on the oldest solids, calcium-aluminium inclusions (CAIs), generated in the protoplanetary disk. The formal GSSA for the Hadean base is the oldest reliable, weighted mean U-corrected Pb-Pb age of 4567.30 ± 0.16 Ma obtained for CAIs in primitive meteorites Allende and Efremovka. This age is supported by the 4568-4567 Ma U-corrected Pb-Pb ages of chondrules in Northwest …


Studying The Impact Of The Geospace Environment On Solar Lithosphere Coupling And Earthquake Activity, Dimitar Ouzounov, Galina Khachikyan 2023 Chapman University

Studying The Impact Of The Geospace Environment On Solar Lithosphere Coupling And Earthquake Activity, Dimitar Ouzounov, Galina Khachikyan

Mathematics, Physics, and Computer Science Faculty Articles and Research

In solar–terrestrial physics, there is an open question: does a geomagnetic storm affect earthquakes? We expand research in this direction, analyzing the seismic situation after geomagnetic storms (GMs) accompanied by the precipitation of relativistic electrons from the outer radiation belt to form an additional radiation belt (RB) around lower geomagnetic lines. We consider four widely discussed cases in the literature for long-lived (weeks, months) RBs due to GMs and revealed that the 1/GMs 24 March 1991 with a new RB at L~2.6 was followed by an M7.0 earthquake in Alaska, 30 May 1991, near footprint L = 2.69; the 2/GMs …


Radio Insights Into Gamma-Ray Mysteries, Seth M. Bruzewski 2023 University of New Mexico

Radio Insights Into Gamma-Ray Mysteries, Seth M. Bruzewski

Physics & Astronomy ETDs

In the time since its launch, the \textit{Fermi Gamma-Ray Space Telescope} has provided new and unparalleled views of the $\gamma$-ray sky, dramatically increasing our understanding of sources of high-energy radiation. During that same time, however, its ``unassociated'' sources have provided a consistent mystery: approximately one third of the modern gamma-ray sky remains completely unaccounted for in other electromagnetic regimes. While some of the fainter sources simply pose challenges in achieving the necessary signal-to-noise ratio, others are well constrained and have resisted traditional investigations for years, and in some cases, for over a decade. Radio astronomy has traditionally been the best …


Modeling Lithographic Quantum Dots And Donors For Quantum Computation And Simulation, Mitchell Ian Brickson 2023 University of New Mexico

Modeling Lithographic Quantum Dots And Donors For Quantum Computation And Simulation, Mitchell Ian Brickson

Physics & Astronomy ETDs

Our first focus is on few-hole quantum dots in germanium. We use discontinous Galerkin methods to discretize and solve the equations of a highly detailed k·p model that describes these systems, enabling a better understanding of experimental magnetospectroscopy results. We confirm the expected anisotropy of single-hole g-factors and describe mechanisms by which different orbital states have different g-factors. Building on this, we show that the g-factors in Ge holes are suciently sensitive to details of the device electrostatics that magnetospectroscopy data can be used to make a prediction of the underlying confinement potential. The second focus is on designing quantum …


A Creationist Model Of Impacts Throughout The Solar System, Trevor Holt 2023 Origins Education and Research Centre

A Creationist Model Of Impacts Throughout The Solar System, Trevor Holt

Proceedings of the International Conference on Creationism

The Biblical Creationist movement has been scant in attempts to explain features throughout the Solar System such as craters, water ice and other ices, possible flowing water, icy satellites, planet rings, and the asteroids and comets. It has been assumed that much of this was part of the initial Creation. I maintain that the initial Creation was considered “very good” and would not have included destructive items and hence would not show the results of impacts. A model has been developed which can explain all these features being caused by impacts over a short time period The Biblical foundations are …


Four Comets Of 2020 Are First Returning Ice Bodies From The Wave Which Brought Water To Earth At The Time Of Noah's Flood., Trevor Holt 2023 Origins Education and Research Centre

Four Comets Of 2020 Are First Returning Ice Bodies From The Wave Which Brought Water To Earth At The Time Of Noah's Flood., Trevor Holt

Proceedings of the International Conference on Creationism

Introduction. The year 2020 saw the arrival into the Solar System of four comets which have their closest approach to the Sun all within thirty eight days. These comets are:C/2020 F3 Neowise, perihelion 0.296 AU 2020 July 03, C/2020 F8 Swan, perihelion 0.430 AU 2020 May 27, C/2019 Y4 Atlas, perihelion 0.253 AU 2020 May 31 and C/2019 U6 Lemmon, perihelion 0.914 2020 June 18.This gives support to the reliability of the Genesis record of the global flood and the chronology given in the genealogy of Jesus Christ. A paper was presented by the author at the 2013 International Creationist …


Expansion Of The Cosmic Fabric Model To The Inelastic Case, Cameron Ward, Mark Horstemeyer, Tichomir G. Tenev 2023 Liberty University

Expansion Of The Cosmic Fabric Model To The Inelastic Case, Cameron Ward, Mark Horstemeyer, Tichomir G. Tenev

Proceedings of the International Conference on Creationism

This research expands Tenev’s Cosmic Fabric Model (CFM) to include the large strain and inelastic cases which provide new insights into anomalies of General Relativity. CFM considers an ethereal universe (the "cosmic fabric") and applies continuum mechanics at the galactic and cosmic length scales to effectively recover equations from General Relativity where the Laplacian of strain corresponds to the Laplacian of the gravitational potential in the weak field approximation. While still at the very beginning of the research, this project explores several possible leads related to the inelastic behavior of the fabric. (A) With a Poisson ratio of 1, the …


Gwtc-3: Compact Binary Coalescences Observed By Ligo And Virgo During The Second Part Of The Third Observing Run, R. Abbott, T. Abbott, F. Acernese, K. Ackley, C. Adams, N. Adhikari, Soma Mukherjee, Volker Quetschke, Wenhui Wang, Francisco Llamas 2023 The University of Texas Rio Grande Valley

Gwtc-3: Compact Binary Coalescences Observed By Ligo And Virgo During The Second Part Of The Third Observing Run, R. Abbott, T. Abbott, F. Acernese, K. Ackley, C. Adams, N. Adhikari, Soma Mukherjee, Volker Quetschke, Wenhui Wang, Francisco Llamas

Physics and Astronomy Faculty Publications and Presentations

The third Gravitational-Wave Transient Catalog (GWTC-3) describes signals detected with Advanced LIGO and Advanced Virgo up to the end of their third observing run. Updating the previous GWTC-2.1, we present candidate gravitational waves from compact binary coalescences during the second half of the third observing run (O3b) between 1 November 2019, 15 ∶ 00 Coordinated Universal Time (UTC) and 27 March 2020, 17 ∶ 00 UTC. There are 35 compact binary coalescence candidates identified by at least one of our search algorithms with a probability of astrophysical origin p astro > 0.5 . Of these, 18 were previously reported as low-latency …


Craters And Cracks Caused By Accelerated Nuclear Decay Heat Throughout The Solar Systemaccelerated Radioactive Decay Heat In The Solar System And Its Implications For Earth, Don Stenberg Jr. 2023 N/A

Craters And Cracks Caused By Accelerated Nuclear Decay Heat Throughout The Solar Systemaccelerated Radioactive Decay Heat In The Solar System And Its Implications For Earth, Don Stenberg Jr.

Proceedings of the International Conference on Creationism

When we look throughout the solar system, we see evidence for accelerated radioactive decay such as fission tracks and isotope ratios. We also see the major effects of that decay heat, including the thermal expansion of planets and moons, massive lava flows, volcanic activity associated with craters, and more. These findings challenge that conventional impact theory of crater formation, and instead suggest that the creation scientists of the 1600s to 1800s were correct that the majority of craters were probably formed by immense explosions. We can now infer the energy source to be accelerated nuclear decay. If this decay heat …


Genealogical Vs Phylogenetic Mutation Rates: Answering A Challenge, Robert Carter 2023 Creation Ministries International

Genealogical Vs Phylogenetic Mutation Rates: Answering A Challenge, Robert Carter

Proceedings of the International Conference on Creationism

There is a discrepancy between the mutation rate we can measure today and the rate at which evolution is supposed to have proceeded. The former is sometimes called the genealogical mutation rate, for it is obtained by comparing individuals whom we know to be related. The latter is sometimes called the phylogenetic mutation rate. It is calculated by counting the fixed differences between two species and dividing by the estimated time since their common ancestor. Genealogical mutation rates are generally several orders of magnitude faster than phylogenetic estimates. This causes problems for the evolutionary model. For example, using the genealogical …


How Should Recent Creationists Respond To Dark Matter And Dark Energy?, Danny R. Faulkner 2023 Answers in Genesis

How Should Recent Creationists Respond To Dark Matter And Dark Energy?, Danny R. Faulkner

Proceedings of the International Conference on Creationism

Astronomers and cosmologists largely accept the reality of dark matter and dark energy. However, many recent creationists oppose both dark matter and dark energy, though it is not clear why. I propose a review of the evidence for dark matter and dark energy, a survey of creationists’ responses to both, and recommendations of how we ought to view dark matter and dark energy.

There are three lines of evidence for dark matter:

  1. Rotation curves of spiral galaxies
  2. Dispersion velocities of galaxy clusters
  3. Gravitational lensing of distant galaxies and quasars by closer galaxy clusters

The evidence for dark matter goes back …


Temporal And Spectral Analysis Of 1es 2344+514 In Two Flaring States Observed By Veritas, Connor Poggemann 2023 California Polytechnic State University, San Luis Obispo

Temporal And Spectral Analysis Of 1es 2344+514 In Two Flaring States Observed By Veritas, Connor Poggemann

Physics

VERITAS observed the bright blazar 1ES 2344+514 during two flaring periods, one from Dec. 17 to Dec. 18, 2015 (MJD 57373-57374) with a peak flux of ~60% of the Crab and another from Nov. 28 to Dec. 3, 2021 (MJD 59546-59551) with a peak flux of ~20% of the Crab. This blazar, located at a redshift of z = 0.044, is classified as an extreme high-frequency-peaked BL Lacertae object (HBL). It is known to be variable, including several previous day-scale flares: Whipple on Dec. 20, 1995, VERITAS on Dec. 7, 2007, and MAGIC on Aug. 11, 2016. The VERITAS near-nightly …


Godel, Escherian Staircase And Possibility Of Quantum Wormhole With Liquid Crystalline Phase Of Iced-Water - Part Ii: Experiment Description, Victor Christianto, T. Daniel Chandra, Florentin Smarandache 2023 University of New Mexico

Godel, Escherian Staircase And Possibility Of Quantum Wormhole With Liquid Crystalline Phase Of Iced-Water - Part Ii: Experiment Description, Victor Christianto, T. Daniel Chandra, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

The present article was partly inspired by G. Pollack’s book, and also Dadoloff, Saxena & Jensen (2010). As a senior physicist colleague and our friend, Robert N. Boyd, wrote in a journal (JCFA, Vol. 1, No. 2, 2022), for example, things and Beings can travel between Universes, intentionally or unintentionally [4]. In this short remark, we revisit and offer short remark to Neil Boyd’s ideas and trying to connect them with geometry of musical chords as presented by D. Tymoczko and others, then to Escherian staircase and then to Jacob’s ladder which seems to pointto possibility to interpret Jacob’s vision …


An Investigation Of The Accretion Processes In T Tauri And Herbig Ae/Be Systems Using High Resolution Optical And Near-Infrared Spectroscopy, Joshua Kern 2023 Clemson University

An Investigation Of The Accretion Processes In T Tauri And Herbig Ae/Be Systems Using High Resolution Optical And Near-Infrared Spectroscopy, Joshua Kern

All Dissertations

Star and planet formation is intimately tied to the accretion of material from the environments in which they form. During the formation process, disks of gas and dust develop in young stellar objects through which material is facilitated to the star and forming planets. Theoretical models of these accretion processes invoke viscous spreading via hydrodynamics, as well as more complex interactions with magnetic fields be it from the stellar component or the formation environment in order to catalyze these mass flows. These accretion models predict various scenarios including magnetospheric accretion as well as supersonic accretion flows in the disk atmosphere …


Initiation Criteria For The Onset Of Geomagnetic Substorms Based On Auroral Observations And Electrojet Current Signatures, Mayowa Michael Kayode-Adeoye 2023 University of South Alabama

Initiation Criteria For The Onset Of Geomagnetic Substorms Based On Auroral Observations And Electrojet Current Signatures, Mayowa Michael Kayode-Adeoye

<strong> Theses and Dissertations </strong>

In recent years, several substorm onset criteria have been developed, either from auroral observations (many authors) or from auroral electrojet properties such as those described by (Forsyth et al., 2015; Maimaiti et al., 2019; Newell & Gjerloev, 2011; Partamies et al., 2011) The different criteria are being investigated using a low order physics model of the magnetosphere called WINDMI (Spencer et al., 2009) and inferences are being made in line with the WINDMI model. The model variables will be compared with the criteria for substorm onset proposed by examining the SML index.

The WINDMI model uses solar wind and IMF …


Godel, Escherian Staircase And Possibility Of Quantum Wormhole With Liquid Crystalline Phase Of Iced-Water - Part I: Theoretical Underpinning, Victor Christianto, T. Daniel Chandra, Florentin Smarandache 2023 University of New Mexico

Godel, Escherian Staircase And Possibility Of Quantum Wormhole With Liquid Crystalline Phase Of Iced-Water - Part I: Theoretical Underpinning, Victor Christianto, T. Daniel Chandra, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

As a senior physicist colleague and our friend, Robert N. Boyd, wrote in a journal (JCFA, Vol. 1,. 2, 2022), Our universe is but one page in a large book [4]. For example, things and Beings can travel between Universes, intentionally or unintentionally. In this short remark, we revisit and offer short remark to Neil’s ideas and trying to connect them with geometrization of musical chords as presented by D. Tymoczko and others, then to Escher staircase and then to Jacob’s ladder which seems to point to possibility to interpret Jacob’s vision as described in the ancient book of Genesis …


Improving Inferences About Exoplanet Habitability, Risinie D. Perera, Kevin H. Knuth 2023 University at Albany, State University of New York

Improving Inferences About Exoplanet Habitability, Risinie D. Perera, Kevin H. Knuth

Physics Faculty Scholarship

Assessing the habitability of exoplanets (planets orbiting other stars) is of great importance in deciding which planets warrant further careful study. Planets in the habitable zones of stars like our Sun are sufficiently far away from the star so that the light rays from the star can be assumed to be parallel, leading to straightforward analytic models for stellar illumination of the planet’s surface. However, for planets in the close-in habitable zones of dim red dwarf stars, such as the potentially habitable planet orbiting our nearest stellar neighbor, Proxima Centauri, the analytic illumination models based on the parallel ray approximation …


Analytic Distribution Of The Optimal Cross-Correlation Statistic For Stochastic Gravitational-Wave-Background Searches Using Pulsar Timing Arrays, ‪Jeffrey S. Hazboun, Patrick M. Meyers, Joseph D. Romano, Xavier Siemens, Anne M. Archibald 2023 The University of Texas Rio Grande Valley

Analytic Distribution Of The Optimal Cross-Correlation Statistic For Stochastic Gravitational-Wave-Background Searches Using Pulsar Timing Arrays, ‪Jeffrey S. Hazboun, Patrick M. Meyers, Joseph D. Romano, Xavier Siemens, Anne M. Archibald

Physics and Astronomy Faculty Publications and Presentations

We show via both analytical calculation and numerical simulation that the optimal cross-correlation statistic (OS) for stochastic gravitational-wave-background (GWB) searches using data from pulsar timing arrays follows a generalized chi-squared (GX2) distribution—i.e., a linear combination of chi-squared distributions with coefficients given by the eigenvalues of the quadratic form defining the statistic. This observation is particularly important for calculating the frequentist statistical significance of a possible GWB detection, which depends on the exact form of the distribution of the OS signal-to-noise ratio ρˆ ≡ Aˆ 2 gw=σ0 in the absence of GW-induced cross correlations (i.e., the null distribution). Previous discussions of …


Digital Commons powered by bepress