Physical Sciences and Mathematics Commons^™

Investigating The Opal Cubesat’S Ability To Measure Thermospheric Gravity Waves, Kenneth Zia, Michael J. Taylor, Ludger Scherliess

Posters

Understanding the Earth’s lower thermosphere is of high interest to the space science community because of competing forcing due to solar heating above and episodic wave forcing from below. The NSF sponsored OPAL cubesat is designed to measure the temperature profile in this region by observing day-time O2 A time O2 A-band (~760nm) emission on the limb and is expected to be launched from the ISS (International Space Station). To band (~760nm) emission on the limb and is expected to be launched from the ISS (International Space Station). To investigate the instrument’s ability to detect space weather signatures (i.e. solar …

Electrical Detection Of Charge-To- Spin And Spin-To-Charge Conversion In A Topological Insulator Bi2te3 Using Bn/Al2o3 Hybrid Tunnel Barrier, C.H. Li, O.M.J. Van't Erve, C. Yan, L. Li, B.T. Jonker

Faculty & Staff Scholarship

One of the most striking properties of three-dimensional topological insulators (TIs) is spin-momentum locking, where the spin is locked at right angles to momentum and hence an unpolarized charge current creates a net spin polarization. Alternatively, if a net spin is injected into the TI surface state system, it is distinctively associated with a unique carrier momentum and hence should generate a charge accumulation, as in the so-called inverse Edelstein effect. Here using a Fe/Al2O3/BN tunnel barrier, we demonstrate both effects in a single device in Bi2Te3: the electrical detection of the spin accumulationgenerated by an unpolarized current flowing through …

Multidimensional Item Response Theory And The Force Concept Inventory, John Stewart, Cabot Zabriskie, Seth Devore, Gay Stewart

Faculty & Staff Scholarship

Research on the test structure of the Force Concept Inventory (FCI) has largely been performed with exploratory methods such as factor analysis and cluster analysis. Multidimensional Item Response Theory (MIRT) provides an alternative to traditional exploratory factor analysis which allows statistical testing to identify the optimal number of factors. Application of MIRT to a sample of N 1⁄4 4716 FCI post-tests identified a 9-factor solution as optimal. Additional analysis showed that a substantial part of the identified factor structure resulted from the practice of using problem blocks and from pairs of similar questions. Applying MIRT to a reduced set of …

Single-Site Catalyst Promoters Accelerate Metal- Catalyzed Nitroarene Hydrogenation, Liang Wang, Erjia Guan, Jian Zhang, Junhao Yang, Yihan Zhu, Yu Han, Ming Yang, Cheng Cen, Gang Fu, Bruce C. Gates, Feng-Shou Xiao

Faculty & Staff Scholarship

Atomically dispersed supported metal catalysts are drawing wide attention because of the opportunities they offer for new catalytic properties combined with efficient use of the metals. We extend this class of materials to catalysts that incorporate atomically dispersed metal atoms as promoters. The catalysts are used for the challenging nitroarene hydro- genation and found to have both high activity and selectivity. The promoters are single-site Sn on TiO2 supports that incorporate metal nanoparticle catalysts. Represented as M/Sn- TiO2 (M = Au, Ru, Pt, Ni), these catalysts decidedly outperform the unpromoted supported metals, even for hydrogenation of nitroarenes substituted with various …

Cavitons And Spontaneous Hot Flow Anomalies In A Hybrid-Vlasov Global Magnetospheric Simulation, Xochitl Blanco-Cano, Markus Battarbee, Lucile Turc, Andrew P. Dimmock, Emilia K.J. Kilpua, Sanni Hoilijoki, Urs Ganse, David G. Sibeck, Paul A. Cassak, Robert C. Fear, Riku Jarvinen, Liisa Juusola, Yann Pfau-Kempf, Rami Vainio, Minna Palmroth

Faculty & Staff Scholarship

Abstract. In this paper we present the first identification of foreshock cavitons and the formation of spontaneous hot flow anomalies (SHFAs) with the Vlasiator global magne- tospheric hybrid-Vlasov simulation code. In agreement with previous studies we show that cavitons evolve into SHFAs. In the presented run, this occurs very near the bow shock. We report on SHFAs surviving the shock crossing into the down- stream region and show that the interaction of SHFAs with the bow shock can lead to the formation of a magnetosheath cavity, previously identified in observations and simulations. We report on the first identification of long-term …

Enhanced Hot Electron Lifetimes In Quantum Wells With Inhibited Phonon Coupling, Hamidreza Esmaielpour, Vincent R. Whiteside, Herath P. Piyathilaka, Sangeetha Vijeyaragunathan, Bin Wang, Echo Adcock-Smith, Kenneth P. Roberts, Tetsuya D. Mishima, Michael B. Santos, Alan D. Bristow, Ian R. Sellers

Faculty & Staff Scholarship

Hot electrons established by the absorption of high-energy photons typically thermalize on a picosecond time scale in a semiconductor, dissipating energy via various phonon-mediated relaxation pathways. Here it is shown that a strong hot carrier distribution can be produced using a type-II quantum well structure. In such systems it is shown that the dominant hot carrier thermalization process is limited by the radiative recombination lifetime of electrons with reduced wavefunction overlap with holes. It is proposed that the subsequent reabsorption of acoustic and optical phonons is facilitated by a mismatch in phonon dispersions at the InAs-AlAsSb interface and serves to …

Electron Paramagnetic Resonance And Optical Absorption Study Of Acceptors In Cdsip2 Crystals, E M. Scherrer, L E. Halliburton, E M. Golden, K T. Zawilski, P G. Schunemann, F K. Hopkins, K L. Averett, N C. Giles

Faculty & Staff Scholarship

Cadmium silicon diphosphide (CdSiP2) is a nonlinear material often used in optical parametric oscillators (OPOs) to produce tunable laser output in the mid-infrared. Absorption bands associated with donors and acceptors may overlap the pump wave- length and adversely affect the performance of these OPOs. In the present investigation, electron paramagnetic resonance (EPR) is used to identify two unintentionally present acceptors in large CdSiP2 crystals. These are an intrinsic silicon-on-phosphorus anti- site and a copper impurity substituting for cadmium. When exposed to 633 nm laser light at temperatures near or below 80 K, they convert to their neutral paramagnetic charge states …

The Encyclopedia Of Neutrosophic Researchers - Vol. 2, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

This is the second volume of the Encyclopedia of Neutrosophic Researchers, edited from materials offered by the authors who responded to my invitation. The introduction contains a short history of neutrosophics, together with links to the main papers and books. The authors who have published neutrosophic papers, books, or defended neutrosophic master theses or PhD dissertations and are not included in the two ENR volumes, are kindly invited to send their self-presentations or their CVs, a photo, and a list of neutrosophic publications to smarand@unm.edu and neutrosophy@laposte.net to be part of a third volume.

Florentin Smarandache

Spatially Resolved Dust, Gas, And Star Formation In The Dwarf Magellanic Irregular Ngc 4449, D. Calzetti, G W. Wilson, B. T. Draine, H. Roussel, K. E. Johnson, M. H. Heyer, W. F. Wall, K. Grasha, A. Battisti, J. E. Andrews, A. Kirkpatrick, D. Rosa González, O. Vega, J. Puschnig, M. Yun, G. Östlin, A. S. Evans, Y. Tang, James Lowenthal, D. Sánchez-Arguelles

Astronomy: Faculty Publications

We investigate the relation between gas and star formation in subgalactic regions, ˜360 pc to ˜1.5 kpc in size, within the nearby starburst dwarf NGC 4449, in order to separate the underlying relation from the effects of sampling at varying spatial scales. Dust and gas mass surface densities are derived by combining new observations at 1.1 mm, obtained with the AzTEC instrument on the Large Millimeter Telescope, with archival infrared images in the range 8-500 μm from the Spitzer Space Telescope and the Herschel Space Observatory. We extend the dynamic range of our millimeter (and dust) maps at the faint …

Automated Data Processing Architecture For The Gemini Planet Imager Exoplanet Survey, Jason J. Wang, Marshall D. Perrin, Dmitry Savransky, Pauline Arriaga, Jeffrey K. Chilcote, Robert J. De Rosa, Maxwell A. Millar-Blanchaer, Christian Marois, Julien Rameau, Schuyler G. Wolff, Jacob Shapiro, Jean Baptiste Ruffio, Jérôme Maire, Franck Marchis, James R. Graham, Bruce Macintosh, S. Mark Ammons, Vanessa P. Bailey, Travis S. Barman, Sebastian Bruzzone, Joanna Bulger, Tara Cotton, René Doyon, Gaspard Duchêne, Michael P. Fitzgerald, Katherine B. Follette, Stephen Goodsell, Alexandra Z. Greenbaum, Pascale Hibon, Li Wei Hung, Patrick Ingraham, Paul Kalas, Kimberly Ward-Duong, Et Al

Astronomy: Faculty Publications

The Gemini Planet Imager Exoplanet Survey (GPIES) is a multiyear direct imaging survey of 600 stars to discover and characterize young Jovian exoplanets and their environments. We have developed an automated data architecture to process and index all data related to the survey uniformly. An automated and flexible data processing framework, which we term the Data Cruncher, combines multiple data reduction pipelines (DRPs) together to process all spectroscopic, polarimetric, and calibration data taken with GPIES. With no human intervention, fully reduced and calibrated data products are available less than an hour after the data are taken to expedite follow up …

The Leech Exoplanet Imaging Survey: Limits On Planet Occurrence Rates Under Conservative Assumptions, Jordan M. Stone, Andrew J. Skemer, Philip M. Hinz, Mariangela Bonavita, Kaitlin M. Kratter, Anne Lise Maire, Denis Defrere, Vanessa P. Bailey, Eckhart Spalding, Jarron M. Leisenring, S. Desidera, M. Bonnefoy, Beth Biller, Charles E. Woodward, Th Henning, Michael F. Skrutskie, J. A. Eisner, Justin R. Crepp, Jennifer Patience, Gerd Weigelt, Robert J. De Rosa, Joshua Schlieder, Wolfgang Brandner, Dániel Apai, Kate Su, Steve Ertel, Kimberly Ward-Duong, Katie M. Morzinski, Dieter Schertl, Karl Heinz Hofmann, Laird M. Close, Stefan S. Brems

Astronomy: Faculty Publications

We present the results of the largest L' (3.8 μm) direct imaging survey for exoplanets to date, the Large Binocular Telescope Interferometer Exozodi Exoplanet Common Hunt (LEECH). We observed 98 stars with spectral types from B to M. Cool planets emit a larger share of their flux in L' compared to shorter wavelengths, affording LEECH an advantage in detecting low-mass, old, and cold-start giant planets. We emphasize proximity over youth in our target selection, probing physical separations smaller than other direct imaging surveys. For FGK stars, LEECH outperforms many previous studies, placing tighter constraints on the hot-start planet occurrence frequency …

Galaxy And Mass Assembly (Gama): The Consistency Of Gama And Wise Derived Mass-To-Light Ratios, T. Kettlety, J. Hesling, S. Phillipps, M. N. Bremer, M. E. Cluver, E. N. Taylor, J. Bland-Hawthorn, S. Brough, R. De Propris, S. P. Driver, Benne W. Holwerda, L. S. Kelvin, W. Sutherland, A. H. Wright

Faculty Scholarship

Recent work has suggested that mid-IR wavelengths are optimal for estimating the mass-to-light ratios of stellar populations and hence the stellar masses of galaxies. We compare stellar masses deduced from spectral energy distribution (SED) models, fitted to multiwavelength optical-NIR photometry, to luminosities derived from WISE photometry in the W1 and W2 bands at 3.6 and 4.5 μmfor non-star forming galaxies. The SED-derived masses for a carefully selected sample of low-redshift (z≤0.15) passive galaxies agree with the prediction from stellar population synthesis models such that M*/LW1 ≃0.6 for all such galaxies, independent of other stellar population parameters. The small scatter between …

Kelt-19ab: A P ∼ 4.6-Day Hot Jupiter Transiting A Likely Am Star With A Distant Stellar Companion, R. J. Siverd, K. A. Collins, G. Zhou, S. N. Quinn, B. S. Gaudi, K. G. Stassun, M. C. Johnson, A. Bieryla, D. W. Latham, D. R. Ciardi, J. E. Rodriguez, K. Penev, M. Pinsonneault, J. Pepper, J. D. Eastman, H. Relles, J. F. Kielkopf, J. Gregorio, T. E. Oberst, G. F. Aldi, G. A. Esquerdo, M. L. Calkins, P. Berlind, C. D. Dressing, R. Patel, D. J. Stevens, T. G. Beatty, M. B. Lund, J. Labadie-Bartz, R. B. Kuhn, K. D. Colón, D. James, X. Yao, J. A. Johnson, J. T. Wright, N. Mccrady, R. A. Wittenmyer, S. A. Johnson, D. H. Sliski, Eric L.N. Jensen, David H. Cohen, K. K. Mcleod, M. T. Penny, M. D. Joner, D. C. Stephens, S. Villanueva Jr., R. Zambelli, C. Stockdale, P. Evans, T.-G. Tan, I. A. Curtis, P. A. Reed, M. Trueblood, P. Trueblood

Physics & Astronomy Faculty Works

We present the discovery of the giant planet KELT-19Ab, which transits the moderately bright (V ~ 9.9) A8V star TYC 764-1494-1 with an orbital period of 4.61 days. We confirm the planetary nature of the companion via a combination of radial velocities, which limit the mass to ≲ 4.1 M_J (3σ), and a clear Doppler tomography signal, which indicates a retrograde projected spin–orbit misalignment of λ = -179.7 (+3.7)/(-3.8) degrees. Global modeling indicates that the T_eff = 7500 ± 110 K host star has M_* = 1.62 (+0.25)/(-0.20) M_⊙ and R_* = …

Motivations Of Educators For Participating In An Authentic Astronomy Research Experience Professional Development Program, Luisa M. Rebull, T. Roberts, W. Laurence, Michael Fitzgerald, D. A. French, Varoujan Gorjian, G. K. Squires

Research outputs 2014 to 2021

[This paper is part of the Focused Collection on Astronomy Education Research.] The NASA/IPAC Teacher Archive Research Program (NITARP) partners small groups of educators with a research astronomer for a year-long authentic research project. This program aligns well with the characteristics of high-quality professional development (PD) programs and has worked with a total of 103 educators since 2005. In this paper, surveys were explored that were obtained from 74 different educators, at up to four waypoints during the course of 13 months, incorporating data from the class of 2010 through the class of 2017. This paper investigates how participating teachers …

Spectrally-Selective Energy-Harvesting Solar Windows For Public Infrastructure Applications, Mikhail Vasiliev, Kamal Alameh, Mohammad Alam

Research outputs 2014 to 2021

A study of photovoltaic solar window technologies is reported and it focuses on their structural features, functional materials, system development, and suitability for use in practical field applications including public infrastructures and agricultural installations. Energy generation performance characteristics are summarized and compared to theory-limit predictions. Working examples of pilot-trial solar window-based installations are described. We also report on achieving electric power outputs of about 25 Wp/m2 from clear and transparent large-area glass-based solar windows.

Prompt Photon-Jet Angular Correlations At Central Rapidities In P + A Collisions, Sanjin Benić, Adrian Dumitru

Publications and Research

Photon-jet azimuthal correlations in proton-nucleus collisions are a promising tool for gaining information on the gluon distribution of the nucleus in the regime of nonlinear color fields. We compute such correlations from the process $g → q\bar{q}γ$ in the rapidity regime where both the projectile and target light-cone momentum fractions are small. By integrating over the phase space of the quark which emits the photon, subject to the restriction that the photon picks up most of the transverse momentum (to pass an isolation cut), we effectively obtain a g + A → qγ process. For nearly back-to-back photon-jet configurations we …

Scalar Field Vacuum Expectation Value Induced By Gravitational Wave Background, Preston Jones, Patrick Mcdougall, Michael Ragsdale, Douglas Singleton

Publications

We show that a massless scalar field in a gravitational wave background can develop a non-zero vacuum expectation value. We draw comparisons to the generation of a non-zero vacuum expectation value for a scalar field in the Higgs mechanism and with the dynamical Casimir vacuum. We propose that this vacuum expectation value, generated by a gravitational wave, can be connected with particle production from gravitational waves and may have consequences for the early Universe where scalar fields are thought to play an important role.

Herschel Observations Of Edge-On Spirals (Heroes) Iv. Dust Energy Balance Problem, Aleksandr V. Mosenkov, Flor Allaert, Maarten Baes, Simone Bianchi, Peter Camps, Christopher J.R. Clark, Marjorie Decleir, Gert De Geyter, Ilse De Looze, Jacopo Fritz, Gianfranco Gentile, Benne W. Holwerda, Thomas M. Hughes, Fraser Lewis, Matthew W.L. Smith, Joris Verstappen, Sam Verstocken, Sébastien Viaene

Faculty Scholarship

We present results of the detailed dust energy balance study for the seven large edge-on galaxies in the HEROES sample using three-dimensional (3D) radiative transfer (RT) modelling. Based on available optical and near-infrared (NIR) observations of the HEROES galaxies, we derive the 3D distribution of stars and dust in these galaxies. For the sake of uniformity, we apply the same technique to retrieve galaxy properties for the entire sample: we use a stellar model consisting of a Sérsic bulge and three double-exponential discs (a superthin disc for a young stellar population and thin and thick discs for old populations). For …

Feasibility Of The Debris Ring Transit Method For The Solar-Like Star Hd 107146 By An Occulted Galaxy, L. Van Sluijs, D. A.J.H. Vaendel, Benne W. Holwerda, M. A. Kenworthy, G. Schneider

Faculty Scholarship

Occulting galaxy pairs have been used to determine the transmission and dust composition within the foreground galaxy. Observations of the nearly face-on ring-like debris disc around the solar-like star HD 107146 by HST/ACS in 2004 and HST/STIS in 2011 reveal that the debris ring is occulting an extended background galaxy over the subsequent decades. Our aim is to use 2004 Hubble Space Telescope (HST) observations of this system to model the galaxy and apply this to the 2011 observation in order to measure the transmission of the galaxy through the outer regions of the debris disc. We model the galaxy …

Galaxy And Mass Assembly (Gama): The Mechanisms For Quiescent Galaxy Formation At Z < 1, K. Rowlands, V. Wild, N. Bourne, M. Bremer, S. Brough, S. P. Driver, A. M. Hopkins, M. S. Owers, S. Phillipps, K. Pimbblet, A. E. Sansom, L. Wang, M. Alpaslan, J. Bland-Hawthorn, M. Colless, Benne W. Holwerda, E. N. Taylor

Faculty Scholarship

One key problem in astrophysics is understanding how and why galaxies switch off their star formation, building the quiescent population that we observe in the local Universe. From the Galaxy And Mass Assembly and VIsible MultiObject Spectrograph Public Extragalactic Redshift surveys, we use spectroscopic indices to select quiescent and candidate transition galaxies. We identify potentially rapidly transitioning post-starburst (PSB) galaxies and slower transitioning green-valley galaxies. Over the last 8Gyr, the quiescent population has grown more slowly in number density at high masses (M* > 1011M⊙) than at intermediate masses (M* > 1010.6M⊙). There is evolution in both the PSB and green-valley stellar …

Numerical Study Of The Relativistic Three-Body Quantization Condition In The Isotropic Approximation, Raúl A. Briceño, Maxwell T. Hansen, Stephen R. Sharpe

Physics Faculty Publications

We present numerical results showing how our recently proposed relativistic three-particle quantization condition can be used in practice. Using the isotropic (generalized s-wave) approximation, and keeping only the leading terms in the effective range expansion, we show how the quantization condition can be solved numerically in a straightforward manner. In addition, we show how the integral equations that relate the intermediate three-particle infinite-volume scattering quantity, K_df,3, to the physical scattering amplitude can be solved at and below threshold. We test our methods by reproducing known analytic results for the 1/L expansion of the threshold state, the volume …

Isoscalar Ππ; Kk; Ηη Scattering And The Σ; F0; F2 Mesons From Qcd, Raul A. Briceño, Jozef J. Dudek, Robert G. Edwards, David J. Wilson

Physics Faculty Publications

We present the first lattice QCD study of coupled isoscalar ππ;K ¯K; ηη S- and D-wave scattering extracted from discrete finite-volume spectra computed on lattices which have a value of the light quark mass corresponding to m_π ∼ 391 MeV. In the J^P = 0⁺ sector we find analogues of the experimental σ and f₀ (980) states, where the σ appears as a stable bound-state below ππ threshold, and, similar to what is seen in experiment, the f₀ (980) manifests itself as a dip in the ππ cross section in the vicinity of the …

Effect Of Non-Hermiticity On Adiabatic Elimination In Coupled Waveguides, Rahman Sharaf, M. Dehghani, Hamidreza Ramezani

Physics and Astronomy Faculty Publications and Presentations

We investigate the influence of non-Hermiticity on the adiabatic elimination in coupled waveguides.We show that although the total norm of the system is not conserved in parity-time symmetric phase, the dark state intensity remains constant. However, in broken phase the eliminated waveguide loses its darkness, i.e., its field amplitude starts increasing. In both exact and broken phases, the effective Hamiltonian derived from the adiabatic elimination condition describes the dynamics of all states except the dark state. Specifically, it cannot predict the amplification in the intensity of the dark state. Our results can strengthen the control of the dynamics in cavities …

Reactive Oxygen Species Generation In Human Cells By A Novel Magnetic Resonance Imaging Contrast Agent, Li Wang, Eric Lin, Mary J. Johansen, Timothy Madden, Edward Felix, Karen S. Martirosyan, Steven J. Frank

Physics and Astronomy Faculty Publications and Presentations

The novel positive-contrast magnetic resonance imaging (MRI) marker C4 consists of an aqueous solution of cobalt chloride (CoCl 2 ) complexed with the chelator N-acetylcysteine (NAC). We evaluated whether the presence of C4 or its components would produce reactive oxygen species (ROS, including hydroxyl, peroxyl, or other reactive oxygen species) in cultured cells. Human cancer or normal cells were incubated with 1% (w/v) CoCl 2 ·6H 2 O or 2% NAC or a combination of both (1% CoCl 2 ·6H 2 O: 2% NAC in an aqueous solution, abbreviated as Co: NAC) in the presence or absence of H 2 …

Electrostatic Potential And Valence Modulation In La0.7sr0.3mno3 Thin Films, Robbyn Trappen, A. C. Garcia- Castro, Vu Thanh Tra, Chih-Yeh Huang, Wilfredo Ibarra-Hernandez, James Fitch, Sobhit Singh, Jingling Zhou, Guerau Cabrera, Ying-Hao Chu, James M. Lebeau, Aldo H. Romero, Mikel B. Holcomb

Faculty & Staff Scholarship

The Mn valence in thin film La0.7Sr0.3MnO3 was studied as a function of film thickness in the range of 1–16 unit cells with a combination of non-destructive bulk and surface sensitive X-ray absorption spectroscopy techniques. Using a layer-by-layer valence model, it was found that while the bulk averaged valence hovers around its expected value of 3.3, a significant deviation occurs within several unit cells of the surface and interface. These results were supported by first principles calculations. The surface valence increases to up to Mn3.7+, whereas the interface valence reduces down to Mn2.5+. The change in valence from the expected …

Block Copolymer Elastomer With Graphite Filler: Effect Of Processing Conditions And Silane Coupling Agent On The Composite Properties, Denis M. Panaitescu, Raluca Augusta Gabor, Cristian Andi Nicolae, Anca Constantina Parau, Catalin Vitelaru, Valentin Raditoiu, Mircea Chipara

Physics and Astronomy Faculty Publications and Presentations

The control of morphology and interface in poly(styrene-ethylene/butylene-styrene) (SEBS) composites with graphitic fillers is extremely important for the design of piezoresistive sensors for body motion or flexible temperature sensors. The effects of a high amount of graphite (G) and silane coupling agent on the morphology and properties of SEBS composites with anisotropic mechanical properties are reported. The physical and chemical bonding of silane to both G and SEBS surface was proved by EDX and TGA results; this improved interface influenced both the thermal and mechanical properties of the composite. The vinyltriethoxysilane (VS) promoted the formation of char residue and, being …

Identification And Mitigation Of Narrow Spectral Artifacts That Degrade Searches For Persistent Gravitational Waves In The First Two Observing Runs Of Advanced Ligo, P. B. Covas, A. Effler, E. Goetz, P. M. Meyers, A. Neunzert, M. Oliver, B. L. Pearlstone, Volker Quetschke, Karla E. Ramirez, Darkhan Tuyenbayev

Physics and Astronomy Faculty Publications and Presentations

Searches are under way in Advanced LIGO and Virgo data for persistent gravitational waves from continuous sources, e.g. rapidly rotating galactic neutron stars, and stochastic sources, e.g. relic gravitational waves from the Big Bang or superposition of distant astrophysical events such as mergers of black holes or neutron stars. These searches can be degraded by the presence of narrow spectral artifacts (lines) due to instrumental or environmental disturbances. We describe a variety of methods used for finding, identifying and mitigating these artifacts, illustrated with particular examples. Results are provided in the form of lists of line artifacts that can safely …

Toxicity Evaluation Of A Novel Magnetic Resonance Imaging Marker Cocl2-N-Acetylcysteine In Rats, Li Wang, Mihai Gagea, Karen S. Martirosyan, Mary Johansen, Timothy Madden, Lisa Norberg, Kirk S. Culotta, Steven J. Frank

Physics and Astronomy Faculty Publications and Presentations

C4 (cobalt dichloride-N-acetylcysteine [1% CoCl 2 :2% NAC]) is a novel magnetic resonance imaging contrast marker that facilitates visualization of implanted radioactive seeds in cancer brachytherapy. We evaluated the toxicity of C4. Rats were assigned to control (0% CoCl 2 :NAC), low-dose (0.1% CoCl 2 :2% NAC), reference-dose (C4), and high-dose (10% CoCl 2 :2% NAC) groups. Agent was injected into the left quadriceps femoris muscle of the rats. Endpoints were organ and body weights, hematology, and serum chemistry and histopathologic changes of tissues at 48 hours and 28 and 63 days after dosing. Student's t tests were used. No …

The Origin Of The First Neutron Star - Neutron Star Merger, K. Belczynski, A. Askar, M. Arca-Sedda, M. Chruslinska, M. Donnari, M. Giersz, M. Benacquista, R. Spurzem, D. Jin, G. Wiktorowicz, D. Belloni

Physics and Astronomy Faculty Publications and Presentations

The first neutron star-neutron star (NS-NS) merger was discovered on August 17, 2017 through gravitational waves (GW170817) and followed with electromagnetic observations. This merger was detected in an old elliptical galaxy with no recent star formation. We perform a suite of numerical calculations to understand the formation mechanism of this merger. We probe three leading formation mechanisms of double compact objects: classical isolated binary star evolution, dynamical evolution in globular clusters, and nuclear cluster formation to test whether they are likely to produce NS-NS mergers in old host galaxies. Our simulations with optimistic assumptions show current NS-NS merger rates at …

The Green Bank Northern Celestial Cap Pulsar Survey. Ii. The Discovery And Timing Of 10 Pulsars, A. M. Kawash, M. A. Mclaughlin, D. L. Kaplan, M. E. Decesar, L. Levin, D. R. Lorimer, R. S. Lynch, K. Stovall, J. K. Swiggum, E. Fonseca, A. M. Archibald, S. Banaszak, C. M. Biwer, J. Boyles, B. Cui, L. P. Dartez, D. Day, S. Ernst, A. J. Ford, J. Flanigan, S. A. Heatherly, J. W.T. Hessels, J. Hinojosa, F. A. Jenet, C. Karako-Argaman, V. M. Kaspi, V. I. Kondratiev, S. Leake, G. Lunsford, J. G. Martinez

Physics and Astronomy Faculty Publications and Presentations

We present timing solutions for 10 pulsars discovered in 350 MHz searches with the Green Bank Telescope. Nine of these were discovered in the Green Bank Northern Celestial Cap survey and one was discovered by students in the Pulsar Search Collaboratory program during an analysis of drift-scan data. Following the discovery and confirmation with the Green Bank Telescope, timing has yielded phase-connected solutions with high-precision measurements of rotational and astrometric parameters. Eight of the pulsars are slow and isolated, including PSR J0930-2301, a pulsar with a nulling fraction lower limit of ∼30% and a nulling timescale of seconds to minutes. …