Alignment Of The Western And Eastern Passage Tombs At Knowth Tomb 1, 2015 Dublin Institute of Technology
Alignment Of The Western And Eastern Passage Tombs At Knowth Tomb 1, Frank Prendergast, Tom Ray
This report presents a summary account of two surveys undertaken by the authors to determine and interpret the alignments of the western and eastern passage tombs at Knowth, Co. Meath. The findings indicate that contrary to earlier suggestions, the eastern passage and the western passage (inner and outer) are not aligned towards sunrise and sunset respectively at the period of the vernal and autumnal equinoxes.
Report On The Workshop For Life Detection In Samples From Mars, 2014 Portland State University
Report On The Workshop For Life Detection In Samples From Mars, Gerhard Kminek, Catherine Conley, Carlton C. Allen, Douglas H. Bartlett, David W. Beaty, Liane G. Benning, Rohit Bhartia, Penelope J. Boston, Caroline Duchaine, Jack D. Farmer, George J. Flynn, Daniel P. Glavin, Yuri Gorby, John E. Hallsworth, Rakesh Mogul, Duane Moser, P. Buford Price, Ruediger Pukall, David Fernandez-Remolar, Caroline L. Smith, Kenneth M. Stedman, Andrew Steele, Ramunas Stepanauskas, Henry Sun, Jorge L. Vago, Mary A. Voytek, Paul S. Weiss, Frances Westfall
Biology Faculty Publications and Presentations
The question of whether there is or was life on Mars has been one of the most pivotal since Schiaparellis’ telescopic observations of the red planet. With the advent of the space age, this question can be addressed directly by exploring the surface of Mars and by bringing samples to Earth for analysis. The latter, however, is not free of problems. Life can be found virtually everywhere on Earth. Hence the potential for contaminating the Mars samples and compromising their scientiﬁc integrity is not negligible. Conversely, if life is present in samples from Mars, this may represent a potential source ...
Static Interaction Of Black Holes In 1+1 Dimensions, 2014 California Polytechnic State University
Static Interaction Of Black Holes In 1+1 Dimensions, Philip Greenwood
We consider a version of general relativity in two spacetime dimensions, and
study a solution describing two static black holes in the presence of a cosmological
constant. We first analytically find an embedding diagram to visualize the geometry
outside the black holes. We then examine how the two black holes must be
interacting to remain static. Our main result is to show how the black holes behave
effectively like two electric charges. This charge model exhibits both attraction and
repulsion, which evidently balance and moreover are localized in different regions
of space. We also begin an investigation of the black ...
Observational And Theoretical Investigation Of Cylindrical Line Source Blast Theory Using Meteors, 2014 Western University
Observational And Theoretical Investigation Of Cylindrical Line Source Blast Theory Using Meteors, Elizabeth A. Silber
University of Western Ontario - Electronic Thesis and Dissertation Repository
During their passage through the atmosphere meteoroids produce a hypersonic shock which may be recorded at the ground in the form of infrasound. The first objective of this project was to use global infrasound measurements to estimate the influx of large (meter/decameter) objects to Earth and investigate which parameters of their ablation and disruption can be determined using infrasound records. A second objective was to evaluate and extend existing cylindrical line source blast theory for meteoroids by combining new observations with earlier analytical models, and validate these against centimetre-sized optical meteor observations.
The annual terrestrial influx of large meteoroids ...
Cosmic Sound In The Lyman Alpha Forest, 2014 DePaul University
Cosmic Sound In The Lyman Alpha Forest, Spencer Everett, Matt Kwiecien, Cordell Newmiller
Using the Baryon Oscillation Spectroscopic Survey (BOSS) from the Sloan Digital Sky Survey (SDSS), the authors attempt to detect the baryonic acoustic oscillations (BAOs) using the discrete wavelet transform. The wavelet transform is used to construct the power spectrum of intergalactic clouds of matter at large (Mpc) distance scales. It was found that the wavelet transform used here does not have high enough resolution to detect the BAOs. However, the techniques used in this study allow for future improvements in the transform that could potentially resolve the expected peak in the power spectrum and indicate the existence of BAOs.
The Evolution Of And Starburst-Agn Connection In Luminous And Ultraluminous Infrared Galaxies And Their Link To Globular Cluster Formation, Stephanie L. Fiorenza
Dissertations and Theses, 2014-Present
The evolutionary connection between nuclear starbursts and active galactic nuclei (AGN) in luminous infrared galaxies (LIRGs; 1011o
Using new spectrophotometric data, I classify the primary source of IR radiation as being a nuclear starburst or a type of AGN by using the Baldwin-Phillips-Terlevich (BPT) diagrams. I show that for the U/LIRGs in my sample the properties that describe their nuclear starbursts and AGN (e.g. star formation rate (SFR), L[O III], optical D parameter, D4000, and EW(Hδ)) are independent of one another, ensuring that no biases affect correlations between these properties and objects' locations on the BPT ...
Veritas Very High Energy Observations Of The Distant Blazar 1es 0647+250, 2014 Macalester College
Veritas Very High Energy Observations Of The Distant Blazar 1es 0647+250, Margaret R. Molter, Jon Dumm, Lucy Fortson
Macalester Journal of Physics and Astronomy
We perform an analysis of the long- and short-term variability of the very high energy (VHE; above 100 GeV) gamma-ray emission from the newly-detected distant blazar 1ES 0647+250. Both new and archival data from the VERITAS telescope were examined, and no strong evidence for integral flux variability on any timescale was found. This lack of variability is consistent with the application of current ultra-high energy cosmic ray (UHECR) models, which can produce secondary gamma-ray emission along the line of sight from the blazar; it also allows averaging over multiyear timescales without bias, aiding in the construction of spectral energy ...
Finesse Measurement In Fabry-Perot Interferometers, 2014 Macalester College
Finesse Measurement In Fabry-Perot Interferometers, Michael C. Darrow
Macalester Journal of Physics and Astronomy
STAR (Space-time Asymmetry Research) is an experimental satellite that will measure anisotropy in the speed of light to unprecedented resolutions using two orthogonal Fabry- Perot interferometers. In order to achieve the desired level of precision, the optical cavities must have finesse values greater than 100,000. Using two test interferometers, I tested and optimized two different experimental methods for measurement of finesse: full-width half max measurement and cavity ring-down spectroscopy. Although each technique proved valid in its own right, my work suggests that cavity ring-down spectroscopy may be more applicable for the needs of STAR.
Lensed Type Ia Supernovae As Probes Of Cluster Mass Models, 2014 The Florida State University
Lensed Type Ia Supernovae As Probes Of Cluster Mass Models, J. Nordin, David Rubin, J. Richard, G. Aldering
Department of Physics Faculty Publications
Using three magnified Type Ia supernovae (SNe Ia) detected behind CLASH (Cluster Lensing and Supernovae with Hubble) clusters, we perform a first pilot study to see whether standardizable candles can be used to calibrate cluster mass maps created from strong lensing observations. Such calibrations will be crucial when next-generation Hubble Space Telescope cluster surveys (e.g. Frontier) provide magnification maps that will, in turn, form the basis for the exploration of the high-redshift Universe. We classify SNe using combined photometric and spectroscopic observations, finding two of the three to be clearly of Type Ia and the third probable. The SNe ...
Birkhoff Theorems In General Relativity, 2014 Utah State University
Birkhoff Theorems In General Relativity, Charles G. Torre
Charles G. Torre
In the following Maple worksheet I demonstrate three versions of Birkhoff's theorem, which is a characterization of spherically symmetric solutions of the Einstein equations. The three versions considered here correspond to taking the "Einstein equations" to be: (1) the vacuum Einstein equations; (2) the Einstein equations with a cosmological constant (3) the Einstein-Maxwell equations.
Ogden College News, 2014 Western Kentucky University
Ogden College News, Cheryl Stevens, Dean, Odgen College Of Science & Engineering, Western Kentucky University
Ogden College of Science & Engineering Publications
No abstract provided.
Graphic Representation Of Exotic Nuclear Shapes In The Pasta Phase Of Matter In Neutron Stars, 2014 University of Tennessee, Knoxville
Graphic Representation Of Exotic Nuclear Shapes In The Pasta Phase Of Matter In Neutron Stars, Mark A. Kaltenborn
University of Tennessee Honors Thesis Projects
No abstract provided.
Physics Of Gamma-Ray Bursts And Multi-Messenger Signals From Double Neutron Star Mergers, 2014 University of Nevada, Las Vegas
Physics Of Gamma-Ray Bursts And Multi-Messenger Signals From Double Neutron Star Mergers, He Gao
UNLV Theses/Dissertations/Professional Papers/Capstones
My dissertation includes two parts:
Physics of Gamma-Ray Bursts (GRBs): Gamma-ray bursts are multi-wavelength transients, with both prompt gamma-ray emission and late time afterglow emission observed by telescopes in different wavelengths. I have carried out three investigations to understand GRB prompt emission and afterglow. Chapter 2 develops a new method, namely, "Stepwise Filter Correlation" method, to decompose the variability components in a light curve. After proving its reliability through simulations, we apply this method to 266 bright GRBs and find that the majority of the bursts have clear evidence of superposition of fast and slow variability components. Chapter 3 gives ...
Perihelion Precession In General Relativity, 2014 Utah State University
Perihelion Precession In General Relativity, Charles G. Torre
Charles G. Torre
This is a Maple worksheet providing a relatively quick and informal sketch of a demonstration that general relativistic corrections to the bound Kepler orbits introduce a perihelion precession. Any decent textbook will derive this result. My analysis aligns with that found in the old text "Introduction to General Relativity", by Adler, Bazin and Schiffer.
The plan of the analysis is as follows.
* Model the planetary orbits as geodesics in the (exterior) Schwarzschild spacetime.
* Compute the geodesic equations.
* Simplify them using symmetries and first integrals.
* Isolate the differential equation expressing the radial coordinate as a function of orbital angle - the "equation ...
Where Did The First Generation Of Stars Form In The Universe, 2014 University of San Francisco
Where Did The First Generation Of Stars Form In The Universe, Long Yan Yung, Aparna Venkatesan
Creative Activity and Research Day - CARD
The first generation of stars in the universe are expected to contain no heavy elements beyond helium, and are considered “metal-free” Population III stars (or Pop III). These metal-free stars in the early universe are predicted to have hard ionizing photon spectra and unique element yields from their supernovae, leaving signatures through the reionization of the intergalactic medium and the metal enrichment of gas in the early universe. Here, we examine the metal abundances in a variety of systems in the nearby universe, from very metal-poor Galactic halo stars to ultra-faint dwarf spheroidal galaxies, and compare them with the latest ...
Supernovae Wavelet Spectral Index Method: A Step Toward Precision Cosmology, 2014 Cedarville University
Supernovae Wavelet Spectral Index Method: A Step Toward Precision Cosmology, Andrew J. Wagers, Lifan Wang, Steve Asztalos
The Research and Scholarship Symposium
As cosmological probes, Type Ia Supernovae are some of the most useful. These exploding stars are used to measure cosmic distances and are useful to test and refine cosmological models. While SNe Ia are extremely uniform, the need for more precise measurements of the peak magnitude has led to the development of methods to correct current measurements for statistical errors. The work presented here has developed a new method for measuring the strength of spectral lines with a goal of using them as a basis for correcting the measured peak magnitudes. Wavelets were used to decompose the spectra so that ...
Ds/Cft At Uniform Energy Density And A De Sitter “Bluewall”, 2014 University of Kentucky
Ds/Cft At Uniform Energy Density And A De Sitter “Bluewall”, Diptarka Das, Sumit R. Das, K. Narayan
Physics and Astronomy Faculty Publications
We describe a class of spacetimes that are asymptotically de Sitter in the Poincare slicing. Assuming that a dS/CFT correspondence exists, we argue that these are gravity duals to a CFT on a circle leading to uniform energy-momentum density, and are equivalent to an analytic continuation of the Euclidean AdS black brane. These are solutions with a complex parameter which then gives a real energy-momentum density. We also discuss a related solution with the parameter continued to a real number, which we refer to as a de Sitter “bluewall”. This spacetime has two asymptotic de Sitter universes and Cauchy ...
Video-Tutorials For Tech Sign Vocabulary In Astronomy, 2014 Rochester Institute of Technology
Video-Tutorials For Tech Sign Vocabulary In Astronomy, Judy Egelston-Dodd, Simon Ting
Journal of Science Education for Students with Disabilities
This article describes the mediated American Sing Language (ASL) presentation of technical vocabulary and definitions within the context of a web-based astronomy course for first year students at the National Technical Institute for the Deaf at Rochester Institute of Technology (Rochester, NY). Deaf students showed achievement gains with fewer astronomy misconceptions. Also, student ratings of instructor ASL skill, as reported on the student rating system, were higher after students used the ASL vocabulary videos.
Characterizing The Quiescent X-Ray Variability Of The Black Hole Low-Mass X-Ray Binary V404 Cyg, 2014 Wayne State University
Characterizing The Quiescent X-Ray Variability Of The Black Hole Low-Mass X-Ray Binary V404 Cyg, F Bernardini, E. M. Cackett
Physics and Astronomy Faculty Research Publications
We conducted the first long-term (75 d) X-ray monitoring of the black hole low-mass X-ray binary V404 Cyg, with the goal of understanding and characterizing its variability during quiescence. The X-ray light curve of V404 Cyg shows several flares on time-scales of hours with a count rate change of a factor of about 5–8. The root-mean-square variability isFvar = 57.0 ± 3.2 per cent. The first-order structure function is consistent with both a power spectrum of index −1 (flicker noise), or with a power spectrum of index 0 (white noise), implying that the light curve is variable ...
The Unified Astronomy Thesaurus: Bringing Together People, Terms, And Organizations To Classify Infinity... And Beyond!, 2014 University of Massachusetts Medical School
The Unified Astronomy Thesaurus: Bringing Together People, Terms, And Organizations To Classify Infinity... And Beyond!, Katie Frey
University of Massachusetts and New England Area Librarian e-Science Symposium
To create a Unified Astronomy Thesaurus as an open, interoperable, and community supported thesaurus. The UAT will bring together existing Astronomy and Astrophysics vocabularies into a single, freely-available, online thesaurus, available to publishers, authors, and everyone else with an interest in classifying astronomical content.
Because astronomy and astrophysics are fast-moving fields, terms that are common today, such as ‘exoplanets’ and ‘dark energy’, were relatively unknown 10 years ago. In order to keep up with the ever-changing field of astronomy, the UAT will solicit suggestions and recommendations from the astronomy community at large. A librarian will be in place ...