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Articles 691 - 720 of 8856

Full-Text Articles in Astrophysics and Astronomy

Imaging Shapes Of Atomic Nuclei In High-Energy Nuclear Collisions, Star Collaboration Jan 2024

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 …

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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 Jan 2024

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 …

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Mesmerizing Moon Mysteries: Unraveling The Compositions Of Irregular Mare Patches (Imps) Using Remote Observations, Nicholas G. Piskurich Jan 2024

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, …

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The Case For Photothermal Spectroscopy In The Future Of Planetary Science Missions, Christopher T. Cox Jan 2024

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, …

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Verifying And Analyzing Ultra-Compact X-Ray Binaries Via Reflection Spectroscopy, David Louis Moutard Jan 2024

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.

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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 Jan 2024

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 …

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Bridgewater Magazine, Volume 34, Number 1, Spring 2024, Bridgewater State University Jan 2024

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.

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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 Jan 2024

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 …

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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 Jan 2024

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 …

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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 Jan 2024

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 …

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Detailed Report On The Measurement Of The Positive Muon Anomalous Magnetic Moment To 0.20 Ppm, Muon G − 2 Collaboration Jan 2024

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, …

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Observation Of Strong Nuclear Suppression In Exclusive J/Ψ Photoproduction In Au + Au Ultraperipheral Collisions At Rhic, Star Collaboration Jan 2024

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 …

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Strangeness Production In √Snn = 3 Gev Au+Au Collisions At Rhic, The Star Collaboration Jan 2024

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 …

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The Present And Future Of Qcd, P. Achenbach Jan 2024

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 …

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Advancements In Glitch Subtraction Systems For Enhancing Gravitational Wave Data Analysis: A Brief Review, Mohammad Abu Thaher Chowdhury Jan 2024

Advancements In Glitch Subtraction Systems For Enhancing Gravitational Wave Data Analysis: A Brief Review, Mohammad Abu Thaher Chowdhury

Physics & Astronomy Faculty Publications

Glitches are transitory noise artifacts that degrade the detection sensitivity and accuracy of interferometric observatories such as LIGO and Virgo in gravitational wave astronomy. Reliable glitch subtraction techniques are essential for separating genuine gravitational wave signals from background noise and improving the accuracy of astrophysical investigations. This review study summarizes the main glitch subtraction methods used in the industry. We talk about the efficacy of classic time-domain techniques in real-time applications, like matched filtering and regression methods. The robustness of frequency-domain approaches, such as wavelet transformations and spectral analysis, in detecting and mitigating non-stationary glitches is assessed. We also investigate …

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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. Jan 2024

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 …

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The A²Π-X²Σ⁺ Band System Of Sco For M-Type Star Spectral Analysis, Léo Lavy, Adam Pastorek, Peter F. Bernath Jan 2024

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 …

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Passages: The Wide-Ranging, Extreme Intrinsic Properties Of Planck-Selected, Lensed Dusty Star-Forming Galaxies, Patrick S. Kamieneski, Min S. Yun, Kevin C. Harrington, James D. Lowenthal, Q. Daniel Wang, Brenda L. Frye, Eric F. Jiménez-Andrade, Amit Vishwas, Olivia Cooper, Massimo Pascale, Nicholas Foo, Derek Berman, Anthony Englert, Carlos Garcia Diaz Jan 2024

Passages: The Wide-Ranging, Extreme Intrinsic Properties Of Planck-Selected, Lensed Dusty Star-Forming Galaxies, Patrick S. Kamieneski, Min S. Yun, Kevin C. Harrington, James D. Lowenthal, Q. Daniel Wang, Brenda L. Frye, Eric F. Jiménez-Andrade, Amit Vishwas, Olivia Cooper, Massimo Pascale, Nicholas Foo, Derek Berman, Anthony Englert, Carlos Garcia Diaz

Astronomy: Faculty Publications

The PASSAGES (Planck All-Sky Survey to Analyze Gravitationally-lensed Extreme Starbursts) collaboration has recently defined a sample of 30 gravitationally lensed dusty star-forming galaxies (DSFGs). These rare, submillimeter-selected objects enable high-resolution views of the most extreme sites of star formation in galaxies at cosmic noon. Here, we present the first major compilation of strong lensing analyses using lenstool for PASSAGES, including 15 objects spanning z = 1.1-3.3, using complementary information from 0.″6-resolution 1.1 mm Atacama Large Millimeter/submillimeter Array and 0.″4 5 cm Jansky Very Large Array continuum imaging, in tandem with 1.6 μm Hubble and optical imaging with Gemini-S. Magnifications range …

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Decreasing Cross-Coupling In The Tianlai Radio Antenna Array, Nadia Marie Schwartz Bolef Jan 2024

Decreasing Cross-Coupling In The Tianlai Radio Antenna Array, Nadia Marie Schwartz Bolef

Scripps Senior Theses

The 21-cm line is the electromagnetic radiation spectral line created by the change in energy state of neutral hydrogen atoms. This signal can be used for intensity mapping, a method of mapping the large-scale structure of the universe at different redshifts. However, challenges are being faced in the designing and building of the radio antenna arrays used to detect the 21-cm line signal. Currently, cross-coupling between antenna feeds is introducing beam errors and correlated noise that could overpower the signal. One possible solution we are working on is to use a phased array of antenna feeds instead of dishes and …

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Evolution Of Angular Momentum In Triaxial Dark Matter Halos, Tara C. Nester Jan 2024

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 …

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Agn Storm 2. Ix. Studying The Dynamics Of The Ionized Obscurer In Mrk 817 With High-Resolution X-Ray Spectroscopy, Fatima Zaidouni, Erin Kara, Peter Kosec, Missagh Mehdipour, Daniele Rogantini, Gerard A. Kriss, Ehud Behar, Jelle Kaastra, Aaron J. Barth, Edward M. Cackett, Gisella De Rosa, Yasaman Homayouni, Keith Horne, Hermine Landt, Nahum Arav, Misty C. Bentz, Michael S. Brotherton, Elena Dalla Bontà, Maryam Dehghanian, Gary Ferland, Carina Fian, Jonathan Gelbord, Michael R. Goad, Diego H. González Buitrago, Catherine J. Grier, Patrick B. Hall, Chen Hu, Dragana Ilić, Shai Kaspi, Christopher S. Kochanek, Andjelka B. Kovačević, Daniel Kynoch, Collin Lewin, John Montano, Hagai Netzer, Jack M. M. Neustadt, Christos Panagiotou, Ethan R. Partington, Rachel Plesha, Luka Č. Popović, Daniel Proga, Thaisa Storchi-Bergmann, David Sanmartim, Matthew R. Siebert, Matilde Signorini, Marianne Vestergaard, Tim Waters, Ying Zu Jan 2024

Agn Storm 2. Ix. Studying The Dynamics Of The Ionized Obscurer In Mrk 817 With High-Resolution X-Ray Spectroscopy, Fatima Zaidouni, Erin Kara, Peter Kosec, Missagh Mehdipour, Daniele Rogantini, Gerard A. Kriss, Ehud Behar, Jelle Kaastra, Aaron J. Barth, Edward M. Cackett, Gisella De Rosa, Yasaman Homayouni, Keith Horne, Hermine Landt, Nahum Arav, Misty C. Bentz, Michael S. Brotherton, Elena Dalla Bontà, Maryam Dehghanian, Gary Ferland, Carina Fian, Jonathan Gelbord, Michael R. Goad, Diego H. González Buitrago, Catherine J. Grier, Patrick B. Hall, Chen Hu, Dragana Ilić, Shai Kaspi, Christopher S. Kochanek, Andjelka B. Kovačević, Daniel Kynoch, Collin Lewin, John Montano, Hagai Netzer, Jack M. M. Neustadt, Christos Panagiotou, Ethan R. Partington, Rachel Plesha, Luka Č. Popović, Daniel Proga, Thaisa Storchi-Bergmann, David Sanmartim, Matthew R. Siebert, Matilde Signorini, Marianne Vestergaard, Tim Waters, Ying Zu

Physics and Astronomy Faculty Publications

We present the results of the XMM-Newton and NuSTAR observations taken as part of the ongoing, intensive multiwavelength monitoring program of the Seyfert 1 galaxy Mrk 817 by the AGN Space Telescope and Optical Reverberation Mapping 2 (AGN STORM 2) Project. The campaign revealed an unexpected and transient obscuring outflow, never before seen in this source. Of our four XMM-Newton/NuSTAR epochs, one fortuitously taken during a bright X-ray state has strong narrow absorption lines in the high-resolution grating spectra. From these absorption features, we determine that the obscurer is in fact a multiphase ionized wind with an outflow velocity of …

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Agn Storm 2. Viii. Investigating The Narrow Absorption Lines In Mrk 817 Using Hst-Cos Observations, Maryam Dehghanian, Nahum Arav, Gerard A. Kriss, Missagh Mehdipour, Doyee Byun, Gwen Walker, Mayank Sharma, Aaron J. Barth, Misty C. Bentz, Benjamin D. Boizelle, Michael S. Brotherton, Edward M. Cackett, Elena Dalla Bontà, Gisella De Rosa, Gary Ferland, Carina Fian, Alexei V. Filippenko, Jonathan Gelbord, Michael R. Goad, Keith Horne, Yasaman Homayouni, Dragana Ilić, Michael D. Joner, Erin A. Kara, Shai Kaspi, Christopher S. Kochanek, Kirk T. Korista, Peter Kosec, Andjelka B. Kovačević, Hermine Landt, Collin Lewin, Ethan R. Partington, Luka Č. Popović, Daniel Proga, Daniele Rogantini, Matthew R. Siebert, Thaisa Storchi-Bergmann, Marianne Vestergaard, Timothy Waters, Jian-Min Wang, Fatima Zaidouni, Ying Zu Jan 2024

Agn Storm 2. Viii. Investigating The Narrow Absorption Lines In Mrk 817 Using Hst-Cos Observations, Maryam Dehghanian, Nahum Arav, Gerard A. Kriss, Missagh Mehdipour, Doyee Byun, Gwen Walker, Mayank Sharma, Aaron J. Barth, Misty C. Bentz, Benjamin D. Boizelle, Michael S. Brotherton, Edward M. Cackett, Elena Dalla Bontà, Gisella De Rosa, Gary Ferland, Carina Fian, Alexei V. Filippenko, Jonathan Gelbord, Michael R. Goad, Keith Horne, Yasaman Homayouni, Dragana Ilić, Michael D. Joner, Erin A. Kara, Shai Kaspi, Christopher S. Kochanek, Kirk T. Korista, Peter Kosec, Andjelka B. Kovačević, Hermine Landt, Collin Lewin, Ethan R. Partington, Luka Č. Popović, Daniel Proga, Daniele Rogantini, Matthew R. Siebert, Thaisa Storchi-Bergmann, Marianne Vestergaard, Timothy Waters, Jian-Min Wang, Fatima Zaidouni, Ying Zu

Physics and Astronomy Faculty Publications

We observed the Seyfert 1 galaxy Mrk 817 during an intensive multiwavelength reverberation mapping campaign for 16 months. Here, we examine the behavior of narrow UV absorption lines seen in the Hubble Space Telescope/ Cosmic Origins Spectrograph spectra, both during the campaign and in other epochs extending over 14 yr. We conclude that, while the narrow absorption outflow system (at −3750 km s−1 with FWHM = 177 km s−1) responds to the variations of the UV continuum as modified by the X-ray obscurer, its total column density (log NH = 19.5 - +0.13 0.61 cm−2) did not change across all …

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Agn Storm 2. Vi. Mapping Temperature Fluctuations In The Accretion Disk Of Mrk 817, Jack M. M. Neustadt, Christopher S. Kochanek, John Montano, Jonathan M. Gelbord, Aaron J. Barth, Gisella De Rosa, Gerard A. Kriss, Edward M. Cackett, Keith Horne, Erin A. Kara, Hermine Landt, Hagai Netzer, Nahum Arav, Misty C. Bentz, Elena Dalla Bontà, Maryam Dehghanian, Pu Du, Rick Edelson, Gary Ferland, Carina Fian, Travis Fischer, Michael R. Goad, Diego H. González Buitrago, Varoujan Gorjian, Catherine J. Grier, Patrick B. Hall, Yasaman Homayouni, Chen Hu, Dragana Ilić, Michael D. Joner, Jelle Kaastra, Shai Kaspi, Kirk T. Korista, Andjelka B. Kovačević, Collin Lewin, Yan-Rong Li, Ian M. Mchardy, Missagh Mehdipour, Jake A. Miller, Christos Panagiotou, Ethan Partington, Rachel Plesha, Richard W. Pogge, Luka Č. Popović, Daniel Proga, Thaisa Storchi-Bergmann, David Sanmartim, Matthew R. Siebert, Matilde Signorini Jan 2024

Agn Storm 2. Vi. Mapping Temperature Fluctuations In The Accretion Disk Of Mrk 817, Jack M. M. Neustadt, Christopher S. Kochanek, John Montano, Jonathan M. Gelbord, Aaron J. Barth, Gisella De Rosa, Gerard A. Kriss, Edward M. Cackett, Keith Horne, Erin A. Kara, Hermine Landt, Hagai Netzer, Nahum Arav, Misty C. Bentz, Elena Dalla Bontà, Maryam Dehghanian, Pu Du, Rick Edelson, Gary Ferland, Carina Fian, Travis Fischer, Michael R. Goad, Diego H. González Buitrago, Varoujan Gorjian, Catherine J. Grier, Patrick B. Hall, Yasaman Homayouni, Chen Hu, Dragana Ilić, Michael D. Joner, Jelle Kaastra, Shai Kaspi, Kirk T. Korista, Andjelka B. Kovačević, Collin Lewin, Yan-Rong Li, Ian M. Mchardy, Missagh Mehdipour, Jake A. Miller, Christos Panagiotou, Ethan Partington, Rachel Plesha, Richard W. Pogge, Luka Č. Popović, Daniel Proga, Thaisa Storchi-Bergmann, David Sanmartim, Matthew R. Siebert, Matilde Signorini

Physics and Astronomy Faculty Publications

We fit the UV/optical lightcurves of the Seyfert 1 galaxy Mrk 817 to produce maps of the accretion disk temperature fluctuations δT resolved in time and radius. The δT maps are dominated by coherent radial structures that move slowly (v = c) inward and outward, which conflicts with the idea that disk variability is driven only by reverberation. Instead, these slow-moving temperature fluctuations are likely due to variability intrinsic to the disk. We test how modifying the input lightcurves by smoothing and subtracting them changes the resulting δT maps and find that most of the temperature fluctuations exist over relatively …

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Correlations Of Event Activity With Hard And Soft Processes In P + Au Collisions At √S Nn = 200 Gev At The Rhic Star Experiment, Star Collaboration Jan 2024

Correlations Of Event Activity With Hard And Soft Processes In P + Au Collisions At √S Nn = 200 Gev At The Rhic Star Experiment, Star Collaboration

Physics and Astronomy Faculty Publications

With the STAR experiment at the BNL Relativistic Heavy Ion Collider, we characterize √s NN = 200 GeV p + Au collisions by event activity (EA) measured within the pseudorapidity range η ∈ [−5, −3.4] in the Au-going direction and report correlations between this EA and hard- and soft-scale particle production at midrapidity (η ∈ [−1, 1]). At the soft scale, charged particle production in low-EA p + Au collisions is comparable to that in p + p collisions and increases monotonically with increasing EA. At the hard scale, we report measurements of high transverse momentum (pT ) jets in …

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Collision-Energy Dependence Of Deuteron Cumulanorrelations In Au+Au Collisions At Rhicts And Proton-Deuteron C, The Star Collaboration Jan 2024

Collision-Energy Dependence Of Deuteron Cumulanorrelations In Au+Au Collisions At Rhicts And Proton-Deuteron C, The Star Collaboration

Physics and Astronomy Faculty Publications

We report the first measurements of cumulants, up to 4𝑡ℎ order, of deuteron number distributions and proton-deuteron correlations in Au+Au collisions recorded by the STAR experiment in phase-I of Beam Energy Scan (BES) program at the Relativistic Heavy Ion Collider. Deuteron cumulants, their ratios, and proton-deuteron mixed cumulants are presented for different collision centralities covering a range of center-of-mass energy per nucleon pair √𝑠NN = 7.7 to 200 GeV. It is found that the cumulant ratios at lower collision energies favor a canonical ensemble over a grand canonical ensemble in thermal models. An anti-correlation between proton and deuteron multiplicity is …

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Estimate Of Background Baseline And Upper Limit On The Chiral Magnetic Effect In Isobar Collisions At √S Nn = 200 Gev At The Bnl Relativistic Heavy Ion Collider, Star Collaboration Jan 2024

Estimate Of Background Baseline And Upper Limit On The Chiral Magnetic Effect In Isobar Collisions At √S Nn = 200 Gev At The Bnl Relativistic Heavy Ion Collider, Star Collaboration

Physics and Astronomy Faculty Publications

For the search of the chiral magnetic effect (CME), STAR previously presented the results from isobar collisions ( 96/44 Ru + 96/44 Ru, 96/40 Zr + 96/40 Zr) obtained through a blind analysis. The ratio of results in Ru + Ru to Zr + Zr collisions for the CME-sensitive charge-dependent azimuthal correlator (Δγ), normalized by elliptic anisotropy (v2 ), was observed to be close to but systematically larger than the inverse multiplicity ratio. The background baseline for the isobar ratio, Y = (Δγ /v2 )Ru (Δγ /v2 )Zr , is naively expected to be …

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Exclusive J/Ψ, Ψ(2s), And E+E− Pair Production In Au + Au Ultraperipheral Collisions At The Bnl Relativistic Heavy Ion Collider, Star Collaboration Jan 2024

Exclusive J/Ψ, Ψ(2s), And E+E− Pair Production In Au + Au Ultraperipheral Collisions At The Bnl Relativistic Heavy Ion Collider, Star Collaboration

Physics and Astronomy Faculty Publications

Measurements of exclusive J/ψ, ψ (2s), and electron-positron (e+e−) pair photoproduction in Au + Au ultraperipheral collisions are reported by the STAR experiment at √sNN = 200 GeV. We report several first measurements at the BNL Relativistic Heavy Ion Collider, which are (i) J/ψ photoproduction with large momentum transfer up to 2.2 (GeV/c)2 , (ii) coherent J/ψ photoproduction associated with neutron emissions from nuclear breakup, (iii) the rapidity dependence of incoherent J/ψ photoproduction, (iv) the ψ (2s) photoproduction cross section at midrapidity, and (v) e+e− pair photoproduction up to high invariant mass of 6 GeV/c2 . For measurement (ii), the …

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Jet-Hadron Correlations With Respect To The Event Plane In √S Nn = 200 Gev Au + Au Collisions In Star, Star Collaboration Jan 2024

Jet-Hadron Correlations With Respect To The Event Plane In √S Nn = 200 Gev Au + Au Collisions In Star, Star Collaboration

Physics and Astronomy Faculty Publications

Angular distributions of charged particles relative to jet axes are studied in √s NN = 200 GeV Au+Au collisions as a function of the jet orientation with respect to the event plane. This differential study tests the expected path-length dependence of energy loss experienced by a hard-scattered parton as it traverses the hot and dense medium formed in heavy-ion collisions. A second-order event plane is used in the analysis as an experimental estimate of the reaction plane formed by the collision impact parameter and the beam direction. Charged-particle jets with 15 < pT,jet < 20 and 20 < pT,jet < 40 GeV/c were reconstructed with the anti-kT algorithm with radius parameter setting of R = 0.4 in the 20–50% centrality bin to maximize the initial-state eccentricity of the interaction region. The reaction plane fit method is implemented to remove the flow-modulated background with better precision than prior methods. Yields and widths of jet-associated charged-hadron distributions are extracted in three angular bins between the jet axis and the event plane. The event-plane (EP) dependence is further quantified by ratios of the associated yields in different EP bins. No dependence on orientation of the jet axis with respect to the event plane is seen within the uncertainties in the kinematic regime studied. This finding is consistent with a similar experimental observation by ALICE in √s NN = 2.76 TeV Pb-Pb collision data.

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Measurements Of Charged-Particle Multiplicity Dependence Of Higher-Order Net-Proton Cumulants In 𝑝+𝑝 Collisions At √𝑠 = 200 Gev From Star At Rhic, Star Collaboration Jan 2024

Measurements Of Charged-Particle Multiplicity Dependence Of Higher-Order Net-Proton Cumulants In 𝑝+𝑝 Collisions At √𝑠 = 200 Gev From Star At Rhic, Star Collaboration

Physics and Astronomy Faculty Publications

We report on the charged-particle multiplicity dependence of net-proton cumulant ratios up to sixth order from√𝑠 = 200 GeV 𝑝+𝑝 collisions at the Relativistic Heavy Ion Collider (RHIC). The measured ratios 𝐶4 ∕𝐶2, 𝐶5 ∕𝐶1, and 𝐶6 ∕𝐶2 decrease with increased charged-particle multiplicity and rapidity acceptance. Neither the Skellam baselines nor PYTHIA8 calculations account for the observed multiplicity dependence. In addition, the ratios 𝐶5 ∕𝐶1 and 𝐶6 ∕𝐶2 approach negative values in the highest-multiplicity events, which implies that thermalized QCD matter may be formed in 𝑝+𝑝 collisions.

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Measurements Of The 𝑍0 ∕𝛾∗ Cross Section And Transverse Single Spin Asymmetry In 510 Gev 𝑝+𝑝 Collisions, The Star Collaboration Jan 2024

Measurements Of The 𝑍0 ∕𝛾∗ Cross Section And Transverse Single Spin Asymmetry In 510 Gev 𝑝+𝑝 Collisions, The Star Collaboration

Physics and Astronomy Faculty Publications

The differential cross section for 𝑍0 production, measured as a function of the boson’s transverse momentum (𝑝T), provides important constraints on the evolution of the transverse momentum dependent parton distribution functions (TMDs). The transverse single spin asymmetry (TSSA) of the 𝑍0 is sensitive to one of the polarized TMDs, the Sivers function, which is predicted to have the opposite sign in 𝑝 + 𝑝 → 𝑊 ∕𝑍 + 𝑋 from that which enters in semi-inclusive deep inelastic scattering. In this Letter, the STAR Collaboration reports the first measurement of the 𝑍0 ∕𝛾∗ differential cross section as a function of its …

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