Astrophysics and Astronomy Commons^™

Upconversion, Mri Imaging And Optical Trapping Studies Of Silver Nanoparticle Decorated Multifunctional Nagdf4:Yb,Er Nanocomposite, S. Yamini, M. Gunaseelan, Ajithkumar Gangadharan, Silverio A. Lopez, Karen S. Martirosyan, Agnishwar Girigoswami, Basudev Roy, J. Manonmani, Senthilselvan Jayaraman

Physics & Astronomy Faculty Publications

The multifunctional upconversion nanoparticles (UCNPs) are fascinating tool for biological applications. In the present work, photon upconverting NaGdF4:Yb,Er and Ag nanoparticles decorated NaGdF4:Yb,Er (NaGdF4:Yb,Er@Ag) nanoparticles were prepared using a simple polyol process. Rietveld refinement was performed for detailed crystal structural and phase fraction analysis. The morphology of the NaGdF4:Yb,Er@Ag was examined using high-resolution transmission electron microscope, which reveals silver nanoparticles of 8 nm in size were decorated over spherical shaped NaGdF4:Yb,Er nanoparticles with a mean particle size of 90 nm. The chemical compositions were confirmed by EDAX and inductively coupled plasma-optical emission spectrometry analyses. The upconversion luminescence (UCL) of NaGdF4:Yb,Er …

Magnetic Dual Chiral Density Wave: A Candidate Quark Matter Phase For The Interior Of Neutron Stars, Efrain J. Ferrer, Vivian De La Incera

Physics & Astronomy Faculty Publications

n this review, we discuss the physical characteristics of the magnetic dual chiral density wave (MDCDW) phase of dense quark matter and argue why it is a promising candidate for the interior matter phase of neutron stars. The MDCDW condensate occurs in the presence of a magnetic field. It is a single-modulated chiral density wave characterized by two dynamically generated parameters: the fermion quasiparticle mass m and the condensate spatial modulation q. The lowest-Landau-level quasiparticle modes in the MDCDW system are asymmetric about the zero energy, a fact that leads to the topological properties and anomalous electric transport exhibited by …

Constraints From Ligo O3 Data On Gravitational-Wave Emission Due To R-Modes In The Glitching Pulsar Psr J0537-6910, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

We present a search for continuous gravitational-wave emission due to r-modes in the pulsar PSR J0537–6910 using data from the LIGO–Virgo Collaboration observing run O3. PSR J0537–6910 is a young energetic X-ray pulsar and is the most frequent glitcher known. The inter-glitch braking index of the pulsar suggests that gravitational-wave emission due to r-mode oscillations may play an important role in the spin evolution of this pulsar. Theoretical models confirm this possibility and predict emission at a level that can be probed by ground-based detectors. In order to explore this scenario, we search for r-mode emission in the epochs between …

Enhancing Student Learning Of Global Warming Through Reflective Writing, Liang Zeng, Guang Zeng

Physics & Astronomy Faculty Publications

The National Academy of Science has published studies showing strong scientific evidence that global warming is caused by human consumption of fossil fuels, yet recent surveys have shown young adults in the U.S. are disengaged or disagree with this fact. Accordingly, the United Nations Educational, Scientific, and Cultural Organization (UNESCO) published learning objectives to educate the world population on global warming and renewable energy by 2030. In this paper, we introduce a reflective writing activity physics educators can employ to foster a deeper understanding of global warming in introductory college physics and physical science courses, without overloading their teaching time.

Twisted Laminar Superconducting Composite: Mgb2 Embedded Carbon Nanotube Yarns, Ujjal Lamichhane, Gamage C. Dannangoda, Mkhitar Hobosyan, R. A. Shohan, A. Zakhidov, Karen S. Martirosyan

Physics & Astronomy Faculty Publications

Twisted laminar superconducting composite structures based on multi-wall carbon nanotube (MWCNT) yarns were crafted by integrating magnesium and boron homogeneous mixture into the carbon nanotube (CNT) aerogel sheets. After the ignition of the Mg–B–MWCNT system, under the controlled argon environment, the high exothermic reaction between magnesium (Mg) and boron (B) with stoichiometric ratio produced the MgB2@MWCNT superconducting composite yarns. The process was conducted under the controlled argon environment and uniform heating rate in the differential scanning calorimetry and thermogravimetric analyzer. The XRD analysis confirmed that the produced composite yarns contain nano and microscale inclusions of superconducting phase of MgB2. The …

Satcon2: Community Engagement Working Group Report, Aparna Venkatesan, J. D. Lowenthal, Doug Arion, Fernando Avila Castro, Michele Bannister, John Barentine, David Begay, Juan-Carlos Chavez, Sally Carttar, Et Al

Astronomy: Faculty Publications

The SATCON2 Community Engagement Working Group aimed to engage a broad and diverse swath of stakeholders in dark skies and near-Earth space who are impacted by large mega-constellations of tens of thousands of low-Earth orbit (LEO) satellites, beyond professional astronomy alone. The working group consisted of 22 members across 23 time zones including professional and amateur astronomers, members of sovereign Indigenous/First Nations communities, dark-sky advocates, planetarium professionals, and environmental/ecological non-governmental organizations. We set out to work together towards a new and effective conceptual, ethical, legal, and regulatory framework for the protection and sustainability of space and the night sky as …

Satcon2: Executive Summary, Jeffrey Hall, Constance Walker, Meredith Rawls, Jonathan Mcdowell, Robert Seaman, Aparna Venkatesan, J. D. Lowenthal, Richard Green, Kelsie Krafton, Joel Parriott

Astronomy: Faculty Publications

About twenty years ago, rapid advances in technology led to the viability of lightemitting diodes (LEDs) as outdoor lighting. With compelling operational and economic reasons to make the shift from legacy gas-discharge systems, communities around the world began installing white LEDs as their lighting of choice. In time, the side effects of the vastly increased sky glow and blue-rich spectral distribution of white LEDs became apparent, negatively impacting not only ground-based professional and amateur astronomy but also casual appreciation of the sky, flora and fauna, and human health.

Today, we are in the initial years of an analogous watershed moment, …

Neutron Stars In F(R,Lm) Gravity With Realistic Equations Of State: Joint-Constrains With Gw170817, Massive Pulsars, And The Psr J0030+0451 Mass-Radius From Nicer Data, R. V. Lobato, G. A. Carvalho, Carlos A. Bertulani

Faculty Publications

In this work, we investigate neutron stars (NS) in f(R,Lm) theory of gravity for the case f(R,Lm) = R +Lm +σRLm, where R is the Ricci scalar and Lm the Lagrangian matter density. In the termσRLm,σ represents the coupling between the gravitational and particles fields. For the first time the hydrostatic equilibrium equations in the theory are solved considering realistic equations of state and NS masses and radii obtained are subject to joint constrains from massivepulsars,thegravitationalwaveeventGW170817and from the PSR J0030+0451 mass-radius from NASA’s Neutron Star Interior Composition Explorer (NICER) data. We show that in this theory of gravity, the mass-radius …

All-Sky Search For Long-Duration Gravitational-Wave Bursts In The Third Advanced Ligo And Advanced Virgo Run, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

After the detection of gravitational waves from compact binary coalescences, the search for transient gravitational-wave signals with less well-defined waveforms for which matched filtering is not well suited is one of the frontiers for gravitational-wave astronomy. Broadly classified into “short” ≲1  s and “long” ≳1  s duration signals, these signals are expected from a variety of astrophysical processes, including non-axisymmetric deformations in magnetars or eccentric binary black hole coalescences. In this work, we present a search for long-duration gravitational-wave transients from Advanced LIGO and Advanced Virgo’s third observing run from April 2019 to March 2020. For this search, we use …

Detecting And Reconstructing Gravitational Waves From The Next Galactic Core-Collapse Supernova In The Advanced Detector Era, Marek J. Szczepańczyk, Javier M. Antelis, Michael Benjamin, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We performed a detailed analysis of the detectability of a wide range of gravitational waves derived from core-collapse supernova simulations using gravitational-wave detector noise scaled to the sensitivity of the upcoming fourth and fifth observing runs of the Advanced LIGO, Advanced Virgo, and KAGRA. We use the coherent WaveBurst algorithm, which was used in the previous observing runs to search for gravitational waves from core-collapse supernovae. As coherent WaveBurst makes minimal assumptions on the morphology of a gravitational-wave signal, it can play an important role in the first detection of gravitational waves from an event in the Milky Way. We …

Search For Active-Sterile Antineutrino Mixing Using Neutral-Current Interactions With The Nova Experiment, M. A. Acero, P. Adamson, L. Aliaga, N. Anfimov, A. Antoshkin, E. Arrieta-Diaz, L. Asquith, A. Aurisano, A. Back, C. Backhouse, M. Baird, N. Balashov, P. Baldi, B. A. Bambah, S. Bashar, K. Bays, R. Bernstein, B. Bhatnagar, B. Bhuyan, J. Bian, Roberto Petti, Et. Al.

Faculty Publications

This Letter reports results from the first long-baseline search for sterile antineutrinos mixing in an accelerator-based antineutrino-dominated beam. The rate of neutral-current interactions in the two NOvA detectors, at distances of 1 and 810 km from the beam source, is analyzed using an exposure of 12.51×10²⁰ protons-on-target from the NuMI beam at Fermilab running in antineutrino mode. A total of 121 of neutral-current candidates are observed at the far detector, compared to a prediction of 122±11(stat.)±15(syst.) assuming mixing only between three active flavors. No evidence for ⊽ _{μ →} ⊽ _s oscillation is observed. Interpreting this result within a …

All-Sky Search For Long-Duration Gravitational-Wave Bursts In The Third Advanced Ligo And Advanced Virgo Run, Richard Abbott, Thomas D. Abbott, Fausto Acernese, K. Ackley, Teviet Creighton, Mario C. Diaz, F. Llamas, Soma Mukherjee, Volker Quetschke, Wenhui Wang

Physics & Astronomy Faculty Publications

After the detection of gravitational waves from compact binary coalescences, the search for transient gravitational-wave signals with less well-defined waveforms for which matched filtering is not well suited is one of the frontiers for gravitational-wave astronomy. Broadly classified into "short" less than or similar to 1 s and "long" greater than or similar to 1 s duration signals, these signals are expected from a variety of astrophysical processes, including non-axisymmetric deformations in magnetars or eccentric binary black hole coalescences. In this work, we present a search for long-duration gravitational-wave transients from Advanced LIGO and Advanced Virgo's third observing run from …

Detecting And Reconstructing Gravitational Waves From The Next Galactic Core-Collapse Supernova In The Advanced Detector Era, Marek J. Szczepańczyk, Javier M. Antelis, Michael Benjamin, Marco Cavaglia, Dorota Gondek-Rosińska, Travis Hansen, Soma Mukherjee, Gaukhar Nurbek, Satzhan Sitmukhambetov, Oscar Valdez

Physics & Astronomy Faculty Publications

We performed a detailed analysis of the detectability of a wide range of gravitational waves derived from core-collapse supernova simulations using gravitational-wave detector noise scaled to the sensitivity of the upcoming fourth and fifth observing runs of the Advanced LIGO, Advanced Virgo, and KAGRA. We use the coherent WaveBurst algorithm, which was used in the previous observing runs to search for gravitational waves from core-collapse supernovae. As coherent WaveBurst makes minimal assumptions on the morphology of a gravitational-wave signal, it can play an important role in the first detection of gravitational waves from an event in the Milky Way. We …

Modeling And Simulation Of Janus-Like Nanoparticles Formation By Solid-Gas Exothermic Reactions, A. A. Markov, Karen S. Martirosyan

Physics & Astronomy Faculty Publications

Theoretical model for the simulation of synthesis of Janus-like particles (JP) consisting two different phases using the Carbon Combustion Synthesis of Oxides (CCSO) is presented. The model includes the variation of sample initial porosity, carbon concentration and oxygen flow rate used to predict the formation of JP features. The two temperature (2T) combustion model of chemically active submicron-dispersed mixture of two phases including ferroelectric and ferromagnetic was implemented and assessed by using the experimentally estimated activation energy of 112±3.3 kJ/mol and combustion temperature. The experimental values allowed to account the thermal and concentration expansion effect along with the dispersion by …

The Poissonian Origin Of Power Laws In Solar Flare Waiting Time Distributions, Markus J. Aschwanden, Jay R. Johnson

Faculty Publications

In this study we aim for a deeper understanding of the power-law slope, α, of waiting time distributions. Statistically independent events with linear behavior can be characterized by binomial, Gaussian, exponential, or Poissonian size distribution functions. In contrast, physical processes with nonlinear behavior exhibit spatiotemporal coherence (or memory) and "fat tails" in their size distributions that fit power-law-like functions, as a consequence of the time variability of the mean event rate, as demonstrated by means of Bayesian block decomposition in the work of Wheatland et al. In this study we conduct numerical simulations of waiting time distributions N( …

Zeros Of Harmonic Polynomials And Related Applications, Azizah Alrajhi

USF Tampa Graduate Theses and Dissertations

In this thesis, we study topics related to harmonic functions, where we are interested in the maximum number of solutions of a harmonic polynomial equation and how it is related to gravitational lensing. In Chapter 2, we study the conditions that we should have on the real or complex coefficients of a polynomial p to get the maximum number of distinct solutions for the equation p(z) − z¯ 2 = 0, where deg p = 2. In Chapter 3, we discuss the lens equation when the lens is an ellipse, a limac¸on, or a Neumann Oval. Also, we give a …

Testing The Strong Equivalence Principle. Ii. Relating The External Field Effect In Galaxy Rotation Curves To The Large-Scale Structure Of The Universe, Stacy S. Mcgaugh

Faculty Scholarship

Theories of modified gravity generically violate the strong equivalence principle, so that the internal dynamics of a self-gravitating system in freefall depends on the strength of the external gravitational field (the external field effect). We fit rotation curves (RCs) from the SPARC database with a model inspired by Milgromian dynamics (MOND), which relates the outer shape of an RC to the external Newtonian field from the large-scale baryonic matter distribution through a dimensionless parameter e N. We obtain a > 4σ statistical detection of the external field effect (i.e. e N > 0 on average), confirming previous results. We then locate the …

Searches For Continuous Gravitational Waves From Young Supernova Remnants In The Early Third Observing Run Of Advanced Ligo And Virgo, Ligo Scientific Collaboration, Virgo Collaboration, Kagra Collaboration, Tiffany Z. Summerscales

Faculty Publications

We present results of three wide-band directed searches for continuous gravitational waves from 15 young supernova remnants in the first half of the third Advanced LIGO and Virgo observing run. We use three search pipelines with distinct signal models and methods of identifying noise artifacts. Without ephemerides of these sources, the searches are conducted over a fRequency band spanning from 10 to 2 kHz. We find no evidence of continuous gravitational radiation from these sources. We set upper limits on the intrinsic signal strain at 95% confidence level in sample subbands, estimate the sensitivity in the full band, and derive …

Search For B0 →Τ±∓ (ℓ=E, Μ) With A Hadronic Tagging Method At Belle Search For B0 →Τ±∓ (ℓ=E, Μ) With A ... H. Atmacan Et Al., H. Atmacan, A. J. Schwartz, K. Kinoshita, I. Adachi, K. Adamczyk, H. Aihara, S. Al Said, D. M. Asner, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, M. Bauer, P. Behera, K. Belous, J. Bennett, F. Bernlochner, M. Bessner

Faculty and Student Publications

We present a search for the lepton-flavor-violating decays B0→τ±∓, where ℓ=(e,μ), using the full data sample of 772×106 BB¯ pairs recorded by the Belle detector at the KEKB asymmetric-energy e+e- collider. We use events in which one B meson is fully reconstructed in a hadronic decay mode. The τ± lepton is reconstructed indirectly using the momentum of the reconstructed B and that of the ∓ from the signal decay. We find no evidence for B0→τ±∓ decays and set upper limits on their branching fractions at 90% confidence level of B(B0→τ±μ∓)<1.5×10-5 and B(B0→τ±e∓)<1.6×10-5.

Toi-1518b: A Misaligned Ultra-Hot Jupiter With Iron In Its Atmosphere, S. H. C. Cabot, A. Bello-Arufe, J. M. Mendonça, R. Tronsgaard, I. Wong, G. Zhou, L. A. Buchhave, D. A. Fischer, K. G. Stassun, V. Antoci, D. Baker, A. A. Belinski, B. Benneke, L. G. Bouma, J. L. Christiansen, K. A. Collins, M. V. Goliguzova, S. Hagey, J. M. Jenkins, Eric L.N. Jensen, R. C. Kidwell Jr., D. Laloum, B. Massey, K. K. Mcleod, D. W. Latham, E. H. Morgan, G. Ricker, B. S. Safonov, J. E. Schlieder, S. Seager, A. Shporer, J. C. Smith, G. Srdoc, I. A. Strakhov, G. Torres, J. D. Twicken, R. Vanderspek, M. Vezie, J. N. Winn

Physics & Astronomy Faculty Works

We present the discovery of TOI-1518b—an ultra-hot Jupiter orbiting a bright star (V = 8.95). The transiting planet is confirmed using high-resolution optical transmission spectra from EXPRES. It is inflated, with R_p = 1.875 ± 0.053 R_J, and exhibits several interesting properties, including a misaligned orbit (240.34 (+0.93)/(-0.98) degrees) and nearly grazing transit (b = 0.9036 (+0.0061)/(-0.0053)). The planet orbits a fast-rotating F0 host star (T_eff ≃ 7300 K) in 1.9 days and experiences intense irradiation. Notably, the TESS data show a clear secondary eclipse with a depth of 364 ± 28 ppm …