Astrophysics and Astronomy Commons^™

The Lismullin Enclosure:A Designed Ritual Space, Frank Prendergast

Book/Book Chapter

The discovery in 2007 of a prehistoric post-built enclosure at Lismullin, Co. Meath, during archaeological investigations in advance of the construction of the M3 motorway is, arguably, the most significant Irish archaeological discovery of recent times. This appendix summarises a commissioned specialist report on the spatial and archaeoastronomical features of the enclosure.

Contellation: Taurus, Gabriel Chaille

Natural Sciences Student Research Presentations

Using the constellation Taurus, the purpose of this project was to gain insight on how information is gathered about stars and what purpose that information serves.

Constellation: Perseus, Marci Holman

Natural Sciences Student Research Presentations

Using the constellation Perseus, the purpose of this project was to gain insight on how information is gathered about stars and what purpose that information serves. This is a project for the Natural Sciences Poster Session at Parkland College.

Dark Energy Interaction Models, H. Shojaei, D. Waters

Journal of the Arkansas Academy of Science

A specific interaction between dark energy and matter has been introduced in order to present possible solutions to the cosmic coincidence problem. We also compared the result of our differential equations with the experimental supernova data obtained by WMAP.

Carbon Monoxide Adsorption On Platinum-Osmium And Platinum-Ruthenium-Osmium Mixed Nanoparticles, Nicholas Dimakis, Nestor E. Navarro, Eugene S. Smotkin

Physics & Astronomy Faculty Publications

Density functional calculations (DFT) on carbon monoxide (CO) adsorbed on platinum, platinum-osmium, and platinum-ruthenium-osmium nanoclusters are used to elucidate changes on the adsorbate internal bond and the carbon-metal bond, as platinum is alloyed with osmium and ruthenium atoms. The relative strengths of the adsorbate internal bond and the carbon-metal bond upon alloying, which are related to the DFT calculated C–O and C–Pt stretching frequencies, respectively, cannot be explained by the traditional 5σ-donation/2π*-back-donation theoretical model. Using a modified π-attraction σ-repulsion mechanism, we ascribe the strength of the CO adsorbate internal bond to changes in the polarization of the adsorbate-substrate hybrid orbitals …

Massive Quiescent Disk Galaxies In The Candels Survey, Aurora Y. Kesseli

Honors Theses

We used data from the GOODS-S field of the CANDELS survey in order to confirm previous studies that found that large fractions of high-redshift galaxies (z ∼ 2) are disk-dominated (McGrath et al. 2008; van der Wel et al. 2011). In the GOODS-S field we selected out all the massive quiescent disk galaxies by imposing a mass limit of M > 10¹⁰M_⊙ and a redshift range of 0.5 ≤ z ≤ 2.5, and then choosing the quiescent red galaxies from a color-color plot. Once we had our sample, we did a qualitative visual classification of each galaxy and …

The X-Ray And Spectropolarimetric View Of Mass Loss And Transfer In Massive Binary Stars, Jamie Renae Lomax

Electronic Theses and Dissertations

The majority of massive stars are members of binary systems. In order to have a better understanding of their evolutionary pathways, the mass and angular momentum loss from massive binaries needs to be well understood. Self consistent explanations for their behavior need to be valid across many wavelength regimes in order to illuminate key phases of mass loss to completely determine how it affects their evolution. In this dissertation I present the results of X-ray and specropolarimetric studies on one Roche-lobe overflow binary (β Lyr) and two colliding wind binaries (V444 Cyg and WR 140).

In β Lyr a …

Modeling The X-Ray Light Curves Of Cygnus X-3 Possible Role Of The Jet, Osmi Vilhu, Diana Carina Hannikainen

Aerospace, Physics, and Space Science Faculty Publications

Context. We address the physics behind the soft X-ray light curve asymmetries in Cygnus X-3, a well-known microquasar. Aims. Observable eff ects of the jet close to the line-of-sight were investigated and interpreted within the frame of light curve physics. Methods. The path of a hypothetical imprint of the jet, advected by theWolf-Rayet-wind, was computed and its crossing with the line-of-sight during the binary orbit determined. We explored the possibility that physically this “imprint” is a formation of dense clumps triggered by jet bow shocks in the wind (“clumpy trail”). Models for X-ray continuum and emission line light curves were …

Azimuthal Anisotropy Of Π⁰ And Η Mesons In Au + Au Collisions At √Snn=200, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Marcus Hohlmann

Aerospace, Physics, and Space Science Faculty Publications

The azimuthal anisotropy coefficients v₂ and v₄ of π⁰ and η mesons are measured in Au + Au collisions at √sNN=200 GeV as a function of transverse momentum pT (1-14 GeV/c) and centrality. The extracted v₂ coefficients are found to be consistent between the two meson species over the measured pT range. The ratio of v₄/v₂² for π⁰ mesons is found to be independent of pT for 1-9 GeV/c, implying a lack of sensitivity of the ratio to the change of underlying physics with pT. Furthermore, the ratio of v₄/v₂² is systematically larger in central collisions, which may reflect the …

Accompanying Figures For "Rotation Periods Of Small Trojan Asteroids", Linda French

Scholarship

No abstract provided.

Search For Long-Lived Gravitational-Wave Transients Coincident With Long Gamma-Ray Bursts, J. Aasi, Daniel Bessis, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Malik Rakhmanov, Volker Quetschke, Joseph D. Romano, Robert Stone, Lappoon R. Tang, Cristina V. Torres

Physics & Astronomy Faculty Publications

Long gamma-ray bursts (GRBs) have been linked to extreme core-collapse supernovae from massive stars. Gravitational waves (GW) offer a probe of the physics behind long GRBs. We investigate models of long-lived (~10–1000 s) GW emission associated with the accretion disk of a collapsed star or with its protoneutron star remnant. Using data from LIGO’s fifth science run, and GRB triggers from the Swift experiment, we perform a search for unmodeled long-lived GW transients. Finding no evidence of GW emission, we place 90% confidence-level upper limits on the GW fluence at Earth from long GRBs for three waveforms inspired by a …

Scalar Polarization Operator In A Superfluid Medium, Sajib Kumar Barman

Open Access Theses & Dissertations

A QCD-inspired effective theory of fermions is considered to study superfluidity. We calculate the quark propagator in a theory with fermion-fermion condensate at finite density. In this theory color degrees of freedom are absent and the quark-quark interaction is modeled through a Yukawa interaction term. Since the diquark condensate is neutral, the system is a superfluid. To study the response of this superfluid to the scalar field propagation, we find the scalar polarization operator of the system.

The 72-H Webt Microvariability Observation Of Blazar S5 0716+714 In 2009, G Bhatta, Stéphane Vennes

Aerospace, Physics, and Space Science Faculty Publications

Context. The international Whole Earth Blazar Telescope (WEBT) consortium planned and carried out three days of intensive micro-variability observations of S5 0716+714 from February 22, 2009 to February 25, 2009. This object was chosen due to its bright apparent magnitude range, its high declination, and its very large duty cycle for micro-variations. Aims. We report here on the long continuous optical micro-variability light curve of 0716+714 obtained during the multi-site observing campaign during which the Blazar showed almost constant variability over a 0.5 mag range. The resulting light curve is presented here for the first time. Observations from participating observatories …

Compositional Diversity In The Atmospheres Of Hot Neptunes, With Application To Gj 436b, J. I. Moses, M. R. Line, Channon Visscher, M. R. Richardson, N. Nettleman, J. J. Fortney, T. S. Barman, K. B. Stevenson, N. Madhusudhan

Faculty Work Comprehensive List

Neptune-sized extrasolar planets that orbit relatively close to their host stars—often called "hot Neptunes"—are common within the known population of exoplanets and planetary candidates. Similar to our own Uranus and Neptune, inefficient accretion of nebular gas is expected produce hot Neptunes whose masses are dominated by elements heavier than hydrogen and helium. At high atmospheric metallicities of 10-10,000 times solar, hot Neptunes will exhibit an interesting continuum of atmospheric compositions, ranging from more Neptune-like, H₂-dominated atmospheres to more Venus-like, CO₂-dominated atmospheres. We explore the predicted equilibrium and disequilibrium chemistry of generic hot Neptunes and find that …

Chemistry Of Impact-Generated Silicate Melt-Vapor Debris Disks, Channon Visscher, Bruce Fegley Jr.

Faculty Work Comprehensive List

In the giant impact theory for lunar origin, the Moon forms from material ejected by the impact into an Earth-orbiting disk. Here we report the initial results from a silicate melt-vapor equilibrium chemistry model for such impact-generated planetary debris disks. In order to simulate the chemical behavior of a two-phase (melt+vapor) disk, we calculate the temperature-dependent pressure and chemical composition of vapor in equilibrium with molten silicate from 2000 to 4000 K. We consider the elements O, Na, K, Fe, Si, Mg, Ca, Al, Ti, and Zn for a range of bulk silicate compositions (Earth, Moon, Mars, eucrite parent body, …

Unsolved Problems In Special And General Relativity, Florentin Smarandache, Fu Yuhua, Zhao Fengjuan

Branch Mathematics and Statistics Faculty and Staff Publications

This book includes 21 papers written by 23 authors and co-authors. All papers included herein are produced by scholars from People’s Republic of China, except two papers written by Prof. L. Sapogin, V. A. Dzhanibekov, Yu. A. Ryabov from Russia, and by Prof. Florentin Smarandache from USA. The editors hope that all these papers will contribute to the advance of scholarly research on several aspects of Special and General Relativity. This book is suitable for students and scholars interested in studies on physics. The first paper is written by Hua Di. He writes that Einstein’s general theory of relativity cannot …

Fuzzy Analysis Of School Dropouts And Their Life After, Florentin Smarandache, W.B. Vasantha Kandasamy, K. Amal, K. Kandasamy

Branch Mathematics and Statistics Faculty and Staff Publications

In this book authors study and analyze the problem of school dropouts and their life after. The problems can by no means be analyzed by collecting the numerical data. For such data can only serve as information beyond that the data can be of no use, for the school dropouts suffer an environment change after becoming a school dropout. Thus the emotions of the school dropout; is technically involved. A school dropout can be a child labourer, a rag picker or a social miscreant or be in police custody or be in a rehabilitation home if he/she is a runaway. …

Gauge Field Preheating At The End Of Inflation, J. Tate Deskins, John T. Giblin Jr., Robert R. Caldwell

Dartmouth Scholarship

Here we consider the possibility of preheating the Universe via the parametric amplification of a massless, U(1) abelian gauge field. We assume that the gauge field is coupled to the inflaton via a conformal factor with one free parameter. We present the results of high-resolution three-dimensional simulations of this model and show this mechanism efficiently preheats the Universe to a radiation-dominated final state.

Single Spin Asymmetry An In Polarized Proton–Proton Elastic Scattering At √S = 200 Gev, L. Adamczyk, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, A. V. Alakhverdyants, I. Alekseev, J. Alford, C. D. Anson, D. Arkhipkin, E. Aschenauer, S. Bültmann, I. Koralt, D. Plyku

Physics Faculty Publications

We report a high precision measurement of the transverse single spin asymmetry A_N at the center of mass energy √s = 200 GeV in elastic proton–proton scattering by the STAR experiment at RHIC. The A_N was measured in the four-momentum transfer squared t range 0.003 ⩽ | t | ⩽ 0.035 ( GeV / c ) ² , the region of a significant interference between the electromagnetic and hadronic scattering amplitudes. The measured values of A_N and its t-dependence are consistent with a vanishing hadronic spin-flip amplitude, thus providing strong constraints on the ratio of the …

Visualizing And Understanding Tectonism And Volcanism On Earth And Other Terrestrial Bodies, Mladen M. Dordevic

Physics Theses & Dissertations

This dissertation presents new methods of visualizing, teaching, assessing, modeling, and understanding tectonics on Earth and other celestial bodies. Tectonics is the study of planetary lithospheres and includes impact, plate, plume, cryo- and gravitational mechanisms. This dissertation is concerned with plate tectonics and plate/mantle plume interactions. Plate tectonics describes the mainly horizontal motion of lithospheric plates over the asthenosphere. Lithosphere is created at ridges and consumed at subduction zones. In addition to the plate tectonic system, mantle plumes also contribute to mass motions in the subsurface Earth. Both plate tectonics and plume upwelling processes help shape the present form of …