Surf: Understanding And Predicting Urban Convection And Haze,
2018
China Meteorological Administration
Surf: Understanding And Predicting Urban Convection And Haze, X. Liang, S. Miao, J. Li, R. Bornstein, X. Zhang, Y. Gao, F. Chen, X. Cao, Z. Cheng, Craig Clements, W. Dabberdt, A. Ding, D. Ding, J. J. Dou, J.X. Dou, Y. Dou, C.S.B. Grimmond, J. E. González-Cruz, J. He, M. Huang, X. Huang, S. Ju, Q. Li, D. Niyogi, J. Quan, J. Sun, J.Z. Sun, M. Yu, J. Zhang, Y. Zhang, X. Zhao, Z. Zheng, M. Zhou
Faculty Publications, Meteorology and Climate Science
Urbanization modifies atmospheric energy and moisture balances, forming distinct features [e.g., urban heat islands (UHIs) and enhanced or decreased precipitation]. These produce significant challenges to science and society, including rapid and intense flooding, heat waves strengthened by UHIs, and air pollutant haze. The Study of Urban Impacts on Rainfall and Fog/Haze (SURF) has brought together international expertise on observations and modeling, meteorology and atmospheric chemistry, and research and operational forecasting. The SURF overall science objective is a better understanding of urban, terrain, convection, and aerosol interactions for improved forecast accuracy. Specific objectives include a) promoting cooperative international research to improve …
Dust–Gas Scaling Relations And Oh Abundance In The Galactic Ism,
2018
Macquarie University, Australia
Dust–Gas Scaling Relations And Oh Abundance In The Galactic Ism, Hiep Nguyen, J. R. Dawson, M. -A. Miville-Deschênes, Ningyu Tang, Di Li, Carl Heiles, Claire E. Murray, Snežana Stanimirović, Steven J. Gibson, N. M. Mcclure-Griffiths, Thomas Troland, L. Bronfman, R. Finger
Physics and Astronomy Faculty Publications
Observations of interstellar dust are often used as a proxy for total gas column density NH. By comparing Planck thermal dust data (Release 1.2) and new dust reddening maps from Pan-STARRS 1 and 2MASS, with accurate (opacity-corrected) H I column densities and newly published OH data from the Arecibo Millennium survey and 21-SPONGE, we confirm linear correlations between dust optical depth τ353, reddening E(B − V), and the total proton column density NH in the range (1–30) × 1020 cm−2, along sightlines with no molecular gas detections in emission. …
The First Super-Earth Detection From The High Cadence And High Radial Velocity Precision Dharma Planet Survey,
2018
University of Florida
The First Super-Earth Detection From The High Cadence And High Radial Velocity Precision Dharma Planet Survey, Bo Ma, Jian Ge, Matthew Muterspaugh, Michael A. Singer, Gregory W. Henry, Jonay I. González Hernández, Sirinrat Sithajan, Sarik Jeram, Michael H. Williamson, Keivan Stassun, Benjamin Kimock, Frank Varosi, Sidney Schofield, Jian Liu, Scott Powell, Anthony Cassette, Hali Jakeman, Louis Avner, Nolan Grieves, Rory Barnes, Bo Zhao, Sankalp Gilda, Jim Grantham, Greg Stafford, David Savage, Steve Bland, Brent Ealey
Information Systems and Engineering Management Research Publications
The Dharma Planet Survey (DPS) aims to monitor about 150 nearby very bright FGKM dwarfs (within 50 pc) during 2016–2020 for low-mass planet detection and characterization using the TOU very high resolution optical spectrograph (R≈100000, 380–900 nm). TOU was initially mounted to the 2-m Automatic Spectroscopic Telescope at Fairborn Observatory in 2013–2015 to conduct a pilot survey, then moved to the dedicated 50-inch automatic telescope on Mt. Lemmon in 2016 to launch the survey. Here, we report the first planet detection from DPS, a super-Earth candidate orbiting a bright K dwarf star, HD 26965. It is the second brightest star …
Bayesian Hierarchical Modelling Of Initial-Final Mass Relations Across Star Clusters,
2018
Imperial College London
Bayesian Hierarchical Modelling Of Initial-Final Mass Relations Across Star Clusters, Shijing Si, David A. Van Dyk, Ted Von Hippel, Elliot Robinson, Elizabeth Jeffery, David C. Stenning
Publications
The initial-final mass relation (IFMR) of white dwarfs (WDs) plays an important role in stellar evolution. To derive precise estimates of IFMRs and explore how they may vary among star clusters, we propose a Bayesian hierarchical model that pools photometric data from multiple star clusters. After performing a simulation study to show the benefits of the Bayesian hierarchical model, we apply this model to five star clusters: the Hyades, M67, NGC 188, NGC 2168, and NGC 2477, leading to reasonable and consistent estimates of IFMRs for these clusters. We illustrate how a cluster-specific analysis of NGC 188 using its own …
Radon Measurement For Neutrinoless Double Beta Decay,
2018
University of New Mexico
Radon Measurement For Neutrinoless Double Beta Decay, Xavier Carlos Quintana
Physics & Astronomy ETDs
This thesis details the design and operation of a high-sensitivity radon detector for use in background radiation characterization and mitigation for the MAJORANA DEMONSTRATOR Neutrinoless Double Beta Decay Experiment and Large Enriched Germanium Experiment for Neutrinoless Double Beta Decay (LEGEND) Collaboration. Understanding and mitigating background radiation is especially important in searches for very rare nuclear processes, which utilize sensitive detectors. One such rare process is the yet-to-be-observed neutrinoless double beta decay. Observation of this process would imply that the neutrino is its own antiparticle, called a Majorana particle, violate lepton number, and provide experimental constraints on the masses and mixing …
Gamma-Ray Burst Classification: New Insights From Mining Pulse Data,
2018
College of Charleston
Gamma-Ray Burst Classification: New Insights From Mining Pulse Data, Stanley Mcafee, Jon Hakkila
Journal of the South Carolina Academy of Science
Despite being the most energetic electromagnetic explosions in the universe, gamma-ray bursts (GRBs) are still poorly understood. The literature recognizes two potentially different types of GRB progenitors, although statistical data suggest the existence of three GRB classes. Reliable inference of GRB physics depends on the identification of appropriate classification attributes, as well as on the statistical classification techniques used. It has recently been shown that pulses are the basic unit of GRB emission. We use new data describing GRB pulse characteristics, in conjunction with data mining tools, to provide a more reliable gamma-ray burst classification system and place additional constraints …
Path Integral Complexity For Perturbed Cfts,
2018
Kyoto University, Japan
Path Integral Complexity For Perturbed Cfts, Arpan Bhattacharyya, Pawal Caputa, Sumit R. Das, Nilay Kundu, Masamichi Miyaji, Tadashi Takayanagi
Physics and Astronomy Faculty Publications
In this work, we formulate a path-integral optimization for two dimensional conformal field theories perturbed by relevant operators. We present several evidences how this optimization mechanism works, based on calculations in free field theories as well as general arguments of RG flows in field theories. Our optimization is performed by minimizing the path-integral complexity functional that depends on the metric and also on the relevant couplings. Then, we compute the optimal metric perturbatively and find that it agrees with the time slice of the hyperbolic metric perturbed by a scalar field in the AdS/CFT correspondence. Last but not the least, …
Table Of Contents,
2018
University of South Carolina
Table Of Contents
Journal of the South Carolina Academy of Science
No abstract provided.
A 3.5 Million Solar Masses Black Hole In The Centre Of The Ultracompact Dwarf Galaxy Fornax Ucd3,
2018
Moscow State University
A 3.5 Million Solar Masses Black Hole In The Centre Of The Ultracompact Dwarf Galaxy Fornax Ucd3, Anton Afanasiev, Igor Chilingarian, Steffen Mieske, Karina Voggel, Arianna Picotti, Michael Hilker, Anil Seth, Nadine Neumayer, Matthias Frank, Aaron Romanowsky, George Hau, Holger Baumgardt, Christopher Ahn, Jay Strader, Mark Den Brok, Richard Mcdermid, Lee Spitler, Jean Brodie, Jonelle Walsh
Faculty Publications
The origin of ultracompact dwarfs (UCDs), a class of compact stellar systems discovered two decades ago, still remains a matter of debate. Recent discoveries of central supermassive black holes in UCDs likely inherited from their massive progenitor galaxies provide support for the tidal stripping hypothesis. At the same time, on statistical grounds, some massive UCDs might be representatives of the high luminosity tail of the globular cluster luminosity function. Here we present a detection of a 3.3+1.4−1.2×106M⊙ black hole (1σ uncertainty) in the centre of the UCD3 galaxy in the Fornax cluster, which corresponds to 4 per cent of its …
Hst Follow-Up Observations Of Two Bright Z ∼ 8 Candidate Galaxies From The Borg Pure-Parallel Survey,
2018
University of Melbourne
Hst Follow-Up Observations Of Two Bright Z ∼ 8 Candidate Galaxies From The Borg Pure-Parallel Survey, R. C. Livermore, M. Trenti, L. D. Bradley, S. R. Bernard, Benne W. Holwerda, C. A. Mason, T. Treu
Faculty and Staff Scholarship
We present follow-up imaging of two bright (L > L∗) galaxy candidates at z ≳ 8 from the Brightest of Reionizing Galaxies (BoRG) survey with the F098M filter on the Hubble Space Telescope/Wide Field Camera 3 (HST/WFC3). The F098M filter provides an additional constraint on the flux blueward of the spectral break, and the observations are designed to discriminate between low- and high-z photometric redshift solutions for these galaxies. Our results confirm one galaxy, BoRG-0116+1425-747, as a highly probable z ∼ 8 source, but reveal that BoRG-0116+1425-630 - previously the brightest known z > 8 candidate (m AB = 24.5) - is …
Fermi-Bounce Cosmology And Scale-Invariant Power Spectrum,
2018
Dartmouth College
Fermi-Bounce Cosmology And Scale-Invariant Power Spectrum, Stephon Alexander, Cosimo Bambi, Antonino Marcianò, Leonardo Modesto
Dartmouth Scholarship
We develop a non-singular bouncing cosmology using a non-trivial coupling of general relativity to fermionic fields. The usual Big Bang singularity is avoided thanks to a negative energy density contribution from the fermions. Our theory is ghost-free since the fermionic operator that generates the bounce is equivalent to torsion, which has no kinetic terms. The physical system consists of standard general relativity plus a topological sector for gravity, and fermionic matter described by Dirac fields with a non-minimal coupling. We show that a scale invariant power-spectrum generated in the contracting phase can be recovered by suitable choice s of fermion …
White Dwarf Pollution By Asteroids From Secular Resonances,
2018
University of Nevada, Las Vegas
White Dwarf Pollution By Asteroids From Secular Resonances, Jeremy L. Smallwood, Rebecca G. Martin, Mario Livio, Stephen H. Lubow
Physics & Astronomy Faculty Research
In the past few decades, observations have revealed signatures of metals polluting the atmospheres of white dwarfs. The diffusion time-scale for metals to sink from the atmosphere of a white dwarf is of the order of days for a hydrogen-dominated atmosphere. Thus, there must be a continuous supply of metal-rich material accreting onto these white dwarfs. We investigate the role of secular resonances that excite the eccentricity of asteroids allowing them to reach star-grazing orbits leading them to tidal disruption and the formation of a debris disc. Changes in the planetary system during the evolution of the star lead to …
What Powered The Optical Transient At2017gfo Associated With Gw170817?,
2018
Central China Normal University; University of Nevada, Las Vegas
What Powered The Optical Transient At2017gfo Associated With Gw170817?, Shao-Ze Li, Liang-Duan Liu, Yun-Wei Yu, Bing Zhang
Physics & Astronomy Faculty Research
The groundbreaking discovery of the optical transient AT2017gfo associated with GW170817 opens a unique opportunity to study the physics of double neutron star (NS) mergers. We argue that the standard interpretation of AT2017gfo as being powered by radioactive decay of r-process elements faces the challenge of simultaneously accounting for the peak luminosity and peak time of the event, as it is not easy to achieve the required high mass, and especially the low opacity of the ejecta required to fit the data. A plausible solution would be to invoke an additional energy source, which is probably provided by the merger …
Bayesian Analysis Of Two Stellar Populations In Galactic Globular Clusters I: Statistical And Computational Methods,
2018
University of California
Bayesian Analysis Of Two Stellar Populations In Galactic Globular Clusters I: Statistical And Computational Methods, David Stenning, Ted Von Hippel, Rachel Wagner-Kaiser, Elliot Robinson, David Van Dyk, Ata Sarajedini, Nathan Stein
Publications
We develop a Bayesian model for globular clusters composed of multiple stellar populations, extend- ing earlier statistical models for open clusters composed of simple (single) stellar populations (e.g., van Dyk et al. 2009; Stein et al. 2013). Specifically, we model globular clusters with two populations that differ in helium abundance. Our model assumes a hierarchical structuring of the parameters in which physical properties|age, metallicity, helium abundance, distance, absorption, and initial mass|are common to (i) the cluster as a whole or to (ii) individual populations within a cluster, or are unique to (iii) individual stars. An adaptive Markov chain Monte Carlo …
Fitting The Radial Acceleration Relation To Individual Sparc Galaxies,
2018
Case Western Reserve University
Fitting The Radial Acceleration Relation To Individual Sparc Galaxies, Pengfei Li, Stacy Mcgaugh
Faculty Scholarship
Galaxies follow a tight radial acceleration relation (RAR): the acceleration observed at every radius correlates with that expected from the distribution of baryons. We use the Markov chain Monte Carlo method to fit the mean RAR to 175 individual galaxies in the SPARC database, marginalizing over stellar mass-to-light ratio (γ ∗), galaxy distance, and disk inclination. Acceptable fits with astrophysically reasonable parameters are found for the vast majority of galaxies. The residuals around these fits have an rms scatter of only 0.057 dex (~13%). This is in agreement with the predictions of modified Newtonian dynamics (MOND). We further consider a …
Characterization Of Eight Potentially Hazardous Near Earth Asteroids: Rotation Period Analysis And Structure Modeling Via Light Curve Inversion Techniques,
2018
Western Kentucky University
Characterization Of Eight Potentially Hazardous Near Earth Asteroids: Rotation Period Analysis And Structure Modeling Via Light Curve Inversion Techniques, Stacy Jo Hicks
Masters Theses & Specialist Projects
The term “homeland security”, seems to have become synonymous with terrorism in the minds of the general public. However, there are other threats to the security of the United States homeland that can be just as, if not more, devastating than terrorism. Included among these other threats is the potential of an asteroid collision with Earth. Historically, asteroid impact events have been responsible for the devastation of our planet and many of the mass extinction events encountered throughout the geologic record. Knowledge of physical parameters such as structure and rotational dynamics of the asteroid are critical parameters in developing interception …
Molpop-Cep: An Exact, Fast Code For Multi-Level Systems,
2018
Instituto de Astrofísica de Canarias, Spain
Molpop-Cep: An Exact, Fast Code For Multi-Level Systems, Andrés Asensio Ramos, Moshe Elitzur
Physics and Astronomy Faculty Publications
We present MOLPOP-CEP, a universal line transfer code that allows the exact calculation of multi-level line emission from a slab with variable physical conditions for any arbitrary atom or molecule for which atomic data exist. The code includes error control to achieve any desired level of accuracy, providing full confidence in its results. Publicly available, MOLPOP-CEP employs our recently developed coupled escape probability (CEP) technique, whose performance exceeds other exact methods by orders of magnitude. The program also offers the option of an approximate solution with different variants of the familiar escape probability method. As an illustration of the MOLPOP-CEP …
Ion Friction At Small Values Of The Coulomb Logarithm,
2018
Brigham Young University
Ion Friction At Small Values Of The Coulomb Logarithm, Robert Tucker Sprenkle
Theses and Dissertations
We create a dual-species ultracold neutral plasma (UNP) by photo-ionizing Yb and Ca atoms in a dual-species magneto-optical trap. Unlike single-species UNP expansion, these plasmas are well outside of the collisionless (Vlasov) approximation. We observe the mutual interaction of the Yb and Ca ions by measuring the velocity distribution for each ion species separately. We model the expansion using a fluid code including ion-ion friction and compare with experimental results to obtain a value of the Coulomb logarithm of Λ= 0.04.
Finite-Volume Effects Due To Spatially Nonlocal Operators,
2018
Old Dominion University
Finite-Volume Effects Due To Spatially Nonlocal Operators, Raúl A. Briceño, Juan V. Guerrero, Maxwell T. Hansen, Christopher J. Monahan
Physics Faculty Publications
Spatially nonlocal matrix elements are useful lattice-QCD observables in a variety of contexts, for example in determining hadron structure. To quote credible estimates of the systematic uncertainties in these calculations, one must understand, among other things, the size of the finite-volume effects when such matrix elements are extracted from numerical lattice calculations. In this work, we estimate finite- volume effects for matrix elements of nonlocal operators, composed of two currents displaced in a spatial direction by a distance ξ. We find that the finite-volume corrections depend on the details of the matrix element. If the external state is the lightest …
One-Loop Evolution Of Parton Pseudo-Distribution Functions On The Lattice,
2018
Old Dominion University
One-Loop Evolution Of Parton Pseudo-Distribution Functions On The Lattice, Anatoly Radyushkin
Physics Faculty Publications
We incorporate recent calculations of one-loop corrections for the reduced Ioffe-time pseudo-distribution m(v, z(3)(2) thorn to extend the leading-logarithm analysis of lattice data obtained by Orginos et al. We observe that the one-loop corrections contain a large term reflecting the fact that effective distances involved in the most important diagrams are much smaller than the nominal distance z(3). The large correction in this case may be absorbed into the evolution term, and the perturbative expansion used for extraction of parton densities at the μ ≈ 2 GeV scale is under control. The extracted parton distribution is rather close to global …
