Coordinated Cosmic-Ray Observing System (Ccros) Concept Paper,
2024
University of Nebraska-Lincoln
Coordinated Cosmic-Ray Observing System (Ccros) Concept Paper, Trenton E. Franz
School of Natural Resources: Faculty Publications
The Coordinated Cosmic-Ray Observation System Conference (CCROS) was held October 14-16, 2024, at the University of Nebraska-Lincoln (USA), and seven strategic priorities and needs were identified.
Imaging Shapes Of Atomic Nuclei In High-Energy Nuclear Collisions,
2024
University of Kentucky
Imaging Shapes Of Atomic Nuclei In High-Energy Nuclear Collisions, Star Collaboration
Physics and Astronomy Faculty Publications
Atomic nuclei are self-organized, many-body quantum systems bound by strong nuclear forces within femtometre-scale space. These complex systems manifest a variety of shapes1–3 , traditionally explored using non-invasive spectroscopic techniques at low energies4,5 . However, at these energies, their instantaneous shapes are obscured by long-timescale quantum fluctuations, making direct observation challenging. Here we introduce the collective-flow-assisted nuclear shape-imaging method, which images the nuclear global shape by colliding them at ultrarelativistic speeds and analysing the collective response of outgoing debris. This technique captures a collision-specific snapshot of the spatial matter distribution within the nuclei, which, through the hydrodynamic expansion, imprints patterns …
On The Particle Acceleration Mechanisms In A Double Radio Relic Galaxy Cluster, Abell 1240,
2024
Berklee College of Music
On The Particle Acceleration Mechanisms In A Double Radio Relic Galaxy Cluster, Abell 1240, Arnab Sarkar, Felipe Andrade-Santos, Reinout J. Van Weeren, Ralph P. Kraft, Duy N. Hoang, Timothy W. Shimwell, Paul Nulsen, William Foreman, Scott Randall, Yuanyuan Su, Priyanka Chakraborty, Christine Jones, Eric Miller, Mark Bautz, Catherine E. Grant
Faculty Works
We present a 368 ks deep Chandra observation of Abell 1240, a binary merging galaxy cluster at a redshift of 0.195 with two brightest cluster galaxies that may have passed each other 0.3 Gyr ago. Building upon previous investigations involving Giant Metrewave Radio Telescope, Very Large Array, and LOFAR data, our study focuses on two prominent extended radio relics at the northwest (NW) and southeast (SE) of the cluster core. By leveraging the high-resolution Chandra imaging, we have identified two distinct surface-brightness edges at ∼1 Mpc and 1.2 Mpc NW and SE of the cluster center, respectively, coinciding with the …
Latent Space Dynamics Learning For Stiff Collisional-Radiative Models,
2024
Old Dominion University
Latent Space Dynamics Learning For Stiff Collisional-Radiative Models, Xuping Xie, Qi Tang, Xianzhu Tang
Mathematics & Statistics Faculty Publications
In this work, we propose a data-driven method to discover the latent space and learn the corresponding latent dynamics for a collisional-radiative (CR) model in radiative plasma simulations. The CR model, consisting of high-dimensional stiff ordinary differential equations, must be solved at each grid point in the configuration space, leading to significant computational costs in plasma simulations. Our method employs a physics-assisted autoencoder to extract a low-dimensional latent representation of the original CR system. A flow map neural network is then used to learn the latent dynamics. Once trained, the reduced surrogate model predicts the entire latent dynamics given only …
Mesmerizing Moon Mysteries: Unraveling The Compositions Of Irregular Mare Patches (Imps) Using Remote Observations,
2024
University of Central Florida
Mesmerizing Moon Mysteries: Unraveling The Compositions Of Irregular Mare Patches (Imps) Using Remote Observations, Nicholas G. Piskurich
Graduate Thesis and Dissertation 2023-2024
Compositional characterization of lunar surface features informs our understanding of the Moon's thermal and magmatic evolution. We investigated the compositions of hypothesized volcanic features known as irregular mare patches (IMPs) and their surroundings to constrain formation mechanisms. We used six datasets to assess the composition of 12 IMPs: 1) Moon Mineralogy Mapper (M3) derived spectral parameters (e.g., band center positions, shapes), 2) Lunar Reconnaissance Orbiter (LRO) Diviner Radiometer Experiment (Diviner) measured Christiansen feature (CF) position, 3) SELENE (Kaguya) Multiband Imager (MI) FeO abundance, 4) Clementine 5-band (Ultraviolet/Visible)-derived FeO abundance, 5) LRO Wide Angle Camera (WAC) TiO2 abundance, …
The Case For Photothermal Spectroscopy In The Future Of Planetary Science Missions,
2024
University of Central Florida
The Case For Photothermal Spectroscopy In The Future Of Planetary Science Missions, Christopher T. Cox
Graduate Thesis and Dissertation 2023-2024
Optical PhotoThermal InfraRed (O-PTIR) is a relatively new spectroscopy method for studying materials. It produces transmission-like spectra using a remote reflectance technique that is rapid, requires little sample preparation, and is well-suited for the technique to be adapted for a space flight instrument. The method involves a tunable pulsed IR laser creating a photothermal effect on the surface of a material and measuring the distortion of a probing visible laser in the same region of the sample, which can be obtained at sub-micron spatial resolutions. A measurement campaign was performed utilizing Photothermal Spectroscopy Corporation's O-PTIR instrument, mIRage®. In this campaign, …
Verifying And Analyzing Ultra-Compact X-Ray Binaries Via Reflection Spectroscopy,
2024
Wayne State University
Verifying And Analyzing Ultra-Compact X-Ray Binaries Via Reflection Spectroscopy, David Louis Moutard
Wayne State University Dissertations
A low-mass X-ray binary (LMXB) is a compact object, such as a neutron star (NS) or black hole (BH), which is accreting material from a stellar companion via a process called Roche-lobe overflow. An ultra-compact X-ray binary (UCXB) is a subset of these systems defined by a shorter orbital period (< 80 minutes, compared to the hours to days seen in LMXBs). This shorter orbital period implies that the companion is more compact than a main sequence type star, often being a white dwarf (WD). These systems are important to study, as the compact nature of both objects in a tight orbit produces low frequency gravitational waves that will affect the next generation of multi-messenger astronomy. By observing UCXBs we can help to understand every facet of these unique systems before such missions begin. Over the course of this dissertation, we study a NS-WD UCXB called 4U 0614+091 and a NS UCXB candidate called SLX 1735-269. The primary method used to study these systems is a process called reflection modeling. This process involves collecting X-ray spectra, and modeling various components; a thermal contribution from the NS, non-thermal contribution from an X-ray corona surrounding the compact object, and sometimes thermal contributions from the accretion disk itself when necessary. These make up the standard continuum for an LMXB, but an additional component is applied which accounts for photons from the corona illuminating the disk and being reprocessed by the elements therein. These elements differ between UCXBs and LMXBs, as UCXBs tend to have an overabundance of oxygen with respect to solar, while being nearly devoid of hydrogen, resulting in a unique feature in the low-energy band. We use this fact to attempt to verify the UCXB nature of SLX 1735-269 by comparing reflection models applied to the data. These models contain different chemical abundances, with some designed for standard LMXBs with a main sequence companion and another designed specifically for UCXBs with a WD companion. We find that it is more likely that the source is ultra-compact in nature, but our timing analysis yields no orbital period, so we can not verify this beyond the indirect evidence of abundances. We also use this method to analyzea series of observations of 4U0614+091, which is a confirmed UCXB. This source varies in flux quasi-periodically over the course of a few days. By capturing the source at various stages along this flux evolution and modeling the reflection, we find that the inner disk appears to move away from the NS at the lowest flux state. This is analogous to what is seen in BH LMXB systems, and explains an apparent anti-correlation in the flux of the illuminating corona and that of the reflected emission, as the accretion disk is physically further from the illuminating source. Finally, we focus on a long term analysis of the same source, taking 51 archival spectra and modeling them with a UCXB reflection abundances. We find the source in different states throughout the course of these observations, which allows us to study how certain reflection parameters change as the source varies overall. We find that our results are consistent with the X-ray corona moving closer to the NS during high flux states, where the bulk of the emission is at low energies. This unique subset of sources can help us understand accretion at various scales by drawing comparisons to more massive black hole counterparts.
Refracting Ufos: Solutions For Fermi Questions, May 2024,
2024
Old Dominion University
Refracting Ufos: Solutions For Fermi Questions, May 2024, John Adam
Mathematics & Statistics Faculty Publications
This article, titled "Refracting UFOs: Solutions for Fermi Questions, May 2024," recounts the author's personal experience as a teenager observing a UFO sighting near their home in England. The author used their telescope to observe the object, which turned out to be lights from a distant airplane flying in a circular holding pattern. The article then presents two questions related to the observed phenomenon, including estimating the diameter of the aircraft's path and the banking angle of the aircraft at its speed. The article concludes with a solution to estimating the distance to the aircraft. The information is presented objectively …
Refracting Ufos,
2024
Old Dominion University
Refracting Ufos, John Adam
Mathematics & Statistics Faculty Publications
Question 2: Assuming θ ≈ 2° = π/90 rad, estimate the distance R to the aircraft. Assume that R ≫ d. Question 1: Suppose that the observed “period of oscillation” is 1 min, and the speed of the aircraft is 200 km/h. Estimate the diameter d of the aircraft path (assuming that it is circular). Estimate the banking angle of the aircraft at this speed. While still a teenager (and aspiring astronomer), I became interested in the subject of UFOs (more appropriately named UAPs—see Ref. 1). The region in which I lived (50 km west of London) was in the …
Crowdsourcing Geospatial Data For Earth And Human Observations: A Review,
2024
Emory University
Crowdsourcing Geospatial Data For Earth And Human Observations: A Review, Xiao Huang, Siqin Wang, Di Yang, Tao Hu, Meixu Chen, Mengxi Zhang, Guiming Zhang, Filip Biljecki, Tianjun Lu, Lei Zou, Connor Y. H. Wu, Yoo Min Park, Xiao Li, Yunzhe Liu, Hongchao Fan, Jessica Mitchell, Zhenlong Li, Alexander Hohl
Earth and Environmental Sciences Faculty Publications
The transformation from authoritative to user-generated data landscapes has garnered considerable attention, notably with the proliferation of crowdsourced geospatial data. Facilitated by advancements in digital technology and high-speed communication, this paradigm shift has democratized data collection, obliterating traditional barriers between data producers and users. While previous literature has compartmentalized this subject into distinct platforms and application domains, this review offers a holistic examination of crowdsourced geospatial data. Employing a narrative review approach due to the interdisciplinary nature of the topic, we investigate both human and Earth observations through crowdsourced initiatives. This review categorizes the diverse applications of these data and …
Bridgewater Magazine, Volume 34, Number 1, Spring 2024,
2024
Bridgewater State University
Bridgewater Magazine, Volume 34, Number 1, Spring 2024, Bridgewater State University
Bridgewater Magazine
Lighting the Way: the nation's last lighthouse keeper and first woman in that role, Sally Snowman, '76. Also in this issue: The multiple sides of climate change; A program that helps students with an autism spectrum disorder or related social profile gain real-world experience; an article on Peter Weyand, G'88; Two decades of The Bridge; and eclipsing expectations: on-campus viewing event draws hundreds to BSU, observatory.
Agn Storm 2. Vii. A Frequency-Resolved Map Of The Accretion Disk In Mrk 817: Simultaneous X-Ray Reverberation And Uvoir Disk Reprocessing Time Lags,
2024
Massachusetts Institute of Technology
Agn Storm 2. Vii. A Frequency-Resolved Map Of The Accretion Disk In Mrk 817: Simultaneous X-Ray Reverberation And Uvoir Disk Reprocessing Time Lags, Collin Lewin, Erin Kara, Aaron J. Barth, Edward M. Cackett, Gisella De Rosa, Yasaman Homayouni, Keith Horne, Gerard A. Kriss, Hermine Landt, Jonathan Gelbord, John Montano, Nahum Arav, Misty C. Bentz, Benjamin D. Boizelle, Elena Dalla Bontà, Michael S. Brotherton, Maryam Dehghanian, Gary Ferland, Carina Fian, Michael R. Goad, Juan V. Hernández Santisteban, Dragana Ilić, Jelle Kaastra, Shai Kaspi, Kirk T. Korista, Peter Kosec, Andjelka B. Kovačević, Missagh Mehdipour, Jake A. Miller, Hagai Netzer, Jack M. M. Neustadt, Christos Panagiotou, Ethan R. Partington, Luka Č. Popović, David Sanmartim, Marianne Vestergaard, Martin J. Ward, Fatima Zaidouni
Physics and Astronomy Faculty Publications
X-ray reverberation mapping is a powerful technique for probing the innermost accretion disk, whereas continuum reverberation mapping in the UV, optical, and infrared (UVOIR) reveals reprocessing by the rest of the accretion disk and broad-line region (BLR). We present the time lags of Mrk 817 as a function of temporal frequency measured from 14 months of high-cadence monitoring from Swift and ground-based telescopes, in addition to an XMM-Newton observation, as part of the AGN STORM 2 campaign. The XMM-Newton lags reveal the first detection of a soft lag in this source, consistent with reverberation from the innermost accretion flow. These …
Agn Storm 2. V. Anomalous Behavior Of The C Iv Light Curve Of Mrk 817,
2024
Space Telescope Science Institute; The Pennsylvania State University
Agn Storm 2. V. Anomalous Behavior Of The C Iv Light Curve Of Mrk 817, Y. Homayouni, Gerard A. Kriss, Gisella De Rosa, Rachel Plesha, Edward M. Cackett, Michael R. Goad, Kirk Korista, Keith Horne, Travis Fischer, Tim Waters, Aaron J. Barth, Erin A. Kara, Hermine Landt, Nahum Arav, Benjamin D. Boizelle, Misty C. Bentz, Michael S. Brotherton, Doron Chelouche, Elena Dalla Bontà, Maryam Dehghanian, Pu Du, Gary Ferland, Carina Fian, Jonathan Gelbord, Catherine J. Grier, Patrick B. Hall, Chen Hu, Dragana Ilić, Michael D. Joner, Jelle Kaastra, Shai Kaspi, Andjelka B. Kovačević, Daniel Kynoch, Yan-Rong Li, Missagh Mehdipour, Jake A. Miller, Jake Mitchell, John Montano, Hagai Netzer, Jack M. M. Neustadt, Ethan Partington, Luka Č. Popović, Daniel Proga, Thaisa Storchi-Bergmann, David Sanmartim, Matthew R. Siebert, Tommaso Treu, Marianne Vestergaard, Jian-Min Wang, Martin J. Ward, Fatima Zaidouni, Ying Zu
Physics and Astronomy Faculty Publications
An intensive reverberation mapping campaign of the Seyfert 1 galaxy Mrk 817 using the Cosmic Origins Spectrograph on the Hubble Space Telescope revealed significant variations in the response of broad UV emission lines to fluctuations in the continuum emission. The response of the prominent UV emission lines changes over an ∼60 day duration, resulting in distinctly different time lags in the various segments of the light curve over the 14 month observing campaign. One-dimensional echo-mapping models fit these variations if a slowly varying background is included for each emission line. These variations are more evident in the C IV light …
Agn Storm 2. X. The Origin Of The Interband Continuum Delays In Mrk 817,
2024
Tel Aviv University, Israel
Agn Storm 2. X. The Origin Of The Interband Continuum Delays In Mrk 817, Hagai Netzer, Michael R. Goad, Aaron J. Barth, Edward M. Cackett, Keith Horne, Chen Hu, Erin Kara, Kirk T. Korista, Gerard A. Kriss, Collin Lewin, John Montano, Nahum Arav, Ehud Behar, Michael S. Brotherton, Doron Chelouche, Gisella De Rosa, Elena Dalla Bontà, Maryam Dehghanian, Gary Ferland, Carina Fian, Yasaman Homayouni, Dragana Ilić, Shai Kaspi, Andjelka B. Kovačević, Hermine Landt, Luka Č. Popović, Thaisa Storchi-Bergmann, Jian-Min Wang, Fatima Zaidouni
Physics and Astronomy Faculty Publications
The local (z = 0.0315) active galactic nucleus (AGN) Mrk 817 was monitored over more than 500 days with space- borne and ground-based instruments as part of a large international campaign, AGN STORM 2. Here, we present a comprehensive analysis of the broadband continuum variations using detailed modeling of the broad line region (BLR), several types of disk winds classified by their optical depth, and new numerical simulations. We find that diffuse continuum (DC) emission, with additional contributions from strong and broad emission lines, can explain the continuum lags observed in this source during high- and low-luminosity phases. Disk illumination …
Detailed Report On The Measurement Of The Positive Muon Anomalous Magnetic Moment To 0.20 Ppm,
2024
University of Kentucky
Detailed Report On The Measurement Of The Positive Muon Anomalous Magnetic Moment To 0.20 Ppm, Muon G − 2 Collaboration
Physics and Astronomy Faculty Publications
We present details on a new measurement of the muon magnetic anomaly, aμ=(gμ-2)/2. The result is based on positive muon data taken at Fermilab's Muon Campus during the 2019 and 2020 accelerator runs. The measurement uses 3.1 GeV/c polarized muons stored in a 7.1-m-radius storage ring with a 1.45 T uniform magnetic field. The value of aμ is determined from the measured difference between the muon spin precession frequency and its cyclotron frequency. This difference is normalized to the strength of the magnetic field, measured using nuclear magnetic resonance. The ratio is then corrected for small contributions from beam motion, …
Observation Of Strong Nuclear Suppression In Exclusive J/Ψ Photoproduction In Au + Au Ultraperipheral Collisions At Rhic,
2024
University of Kentucky
Observation Of Strong Nuclear Suppression In Exclusive J/Ψ Photoproduction In Au + Au Ultraperipheral Collisions At Rhic, Star Collaboration
Physics and Astronomy Faculty Publications
We report a measurement of exclusive J/ψ and ψ(2s) photoproduction in Au+Au ultraperipheral collisions at sNN=200 GeV using the STAR detector. For the first time, (i) the ψ(2s) photoproduction in midrapidity at the Relativistic Heavy-Ion Collider has been experimentally measured; (ii) nuclear suppression factors are measured for both the coherent and incoherent J/ψ production. At average photon-nucleon center-of-mass energy of 25.0 GeV, the coherent and incoherent J/ψ cross sections of Au nuclei are found to be 71±10% and 36±7%, respectively, of that of free protons. The stronger suppression observed in the incoherent production provides a new experimental handle to study …
Strangeness Production In √Snn = 3 Gev Au+Au Collisions At Rhic,
2024
University of Kentucky
Strangeness Production In √Snn = 3 Gev Au+Au Collisions At Rhic, The Star Collaboration
Physics and Astronomy Faculty Publications
We report multi-differential measurements of strange hadron production ranging from mid- to target-rapidity in Au+Au collisions at a center-of-momentum energy per nucleon pair of √sNN = 3 GeV with the STAR experiment at RHIC. K0 S meson and Λ hyperon yields are measured via their weak decay channels. Collision centrality and rapidity dependences of the transverse momentum spectra and particle ratios are presented. Particle mass and centrality dependence of the average transverse momenta of Λ and K0 S are compared with other strange particles, providing evidence of the development of hadronic rescattering in such collisions. The 4π yields of each …
The Present And Future Of Qcd,
2024
Thomas Jefferson National Accelerator Facility
The Present And Future Of Qcd, P. Achenbach
Physics and Astronomy Faculty Publications
This White Paper presents an overview of the current status and future perspective of QCD research, based on the community inputs and scientific conclusions from the 2022 Hot and Cold QCD Town Meeting. We present the progress made in the last decade toward a deep understanding of both the fundamental structure of the sub-atomic matter of nucleon and nucleus in cold QCD, and the hot QCD matter in heavy ion collisions. We identify key questions of QCD research and plausible paths to obtaining answers to those questions in the near future, hence defining priorities of our research over the coming …
Evolution Of Angular Momentum In Triaxial Dark Matter Halos,
2024
Georgia Southern University
Evolution Of Angular Momentum In Triaxial Dark Matter Halos, Tara C. Nester
Honors College Theses
Galactic halos are believed to form through both the early inflow of dark matter from the cosmic web and mergers over an extended period. At the same time, stellar disks are forming within this evolving halo. How a stellar disk responds to a changing halo is investigated in this study using live n-body disks embedded in an analytic triaxial potential. At triaxialities of a few percent, we find that while there are subtle perturbations in the disk, there is no significant change in the total disk angular momentum. However, between 5 and 10% triaxialities there is a sharp transition to …
The A²Π-X²Σ⁺ Band System Of Sco For M-Type Star Spectral Analysis,
2024
Old Dominion University
The A²Π-X²Σ⁺ Band System Of Sco For M-Type Star Spectral Analysis, Léo Lavy, Adam Pastorek, Peter F. Bernath
Chemistry & Biochemistry Faculty Publications
M-type stars are the most abundant stars in our Galaxy. Their visible spectra are characterized by strong TiO and VO absorption bands with occasional ScO bands near 6000–6100 Å. This region corresponds to the A²Π–X²Σ+ band system and can be used to measure the abundance of ScO. In this work, a new Doppler-limited resolution spectrum of ScO obtained in a hollow-cathode experiment is presented. The A²Π–X²Σ+ electronic transition is analyzed with special care dedicated to fitting the A′²Δ(v+2) ∼ A²Π(v) perturbation. Spectroscopic constants of the A²Π(v) states are reported for v ≤ 9, and a partial fit of …
