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Astrophysics and Astronomy

Journal of the Arkansas Academy of Science

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Full-Text Articles in Physical Sciences and Mathematics

Binary Star Light Curve And Model Of Tyc 3670-588-1 From Professional-Amateur Collaboration, A, J. W. Robertson, B. Mcmath, D. Waters, R. T. Campbell, G. Roberts Jan 2014

Binary Star Light Curve And Model Of Tyc 3670-588-1 From Professional-Amateur Collaboration, A, J. W. Robertson, B. Mcmath, D. Waters, R. T. Campbell, G. Roberts

Journal of the Arkansas Academy of Science

We present the orbital light curve and model system parameters of a newly discovered eclipsing binary star in the constellation of Perseus. Our professional-amateur astronomy collaboration between Arkansas Tech University (ATU), the Central Arkansas Astronomy Society (CAAS) and Whispering Pine Observatory, produced photometry in two wavelengths (Johnson V and R) in order to model the system for fundamental parameters with a binary modeling code. We determined that this binary system contains two F-type stars orbiting each other with a short orbital period and having the following characteristics for the two components: mass ratio (q ~ 0.92), temperatures (T1~ 7170 K, …


Study Of The Relation Between The Spiral Arm Pitch Angle And The Kinetic Energy Of Random Motions Of The Host Spiral Galaxies, A, I. Al-Baidhany, M. Seigar, P. Treuthardt, A. Sierra, B. Davis, D. Kennefick, J. Kennefick, C. Lacy, Z. A. Toma, W. Jabbar Jan 2014

Study Of The Relation Between The Spiral Arm Pitch Angle And The Kinetic Energy Of Random Motions Of The Host Spiral Galaxies, A, I. Al-Baidhany, M. Seigar, P. Treuthardt, A. Sierra, B. Davis, D. Kennefick, J. Kennefick, C. Lacy, Z. A. Toma, W. Jabbar

Journal of the Arkansas Academy of Science

In this work, we report a relation between the kinetic energy of random motions of the corresponding host galaxies and spiral arm pitch angles (Mdynσ2- P), (M*σ2- P) where Mdyn is the bulge dynamical mass, M* is bulge stellar mass, and σ is the velocity dispersion of the host galaxy bulge. We measured the spiral arm pitch angle (P) for a sample of Spitzer/IRAC 3.6-μm images of 54 spiral galaxies, estimated by using a 2D Fast Fourier Transform decomposition technique (2DFFT). We selected a sample of nearly face-on spiral galaxies and used IRAF ellipse to determine the ellipticity and major-axis …


Dark Energy Interaction Models, H. Shojaei, D. Waters Jan 2013

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.


Interacting Dark Energy Models And The Cosmic Coincidence Problem, H. Shojaei, C. Smith, D. Waters Jan 2012

Interacting Dark Energy Models And The Cosmic Coincidence Problem, H. Shojaei, C. Smith, D. Waters

Journal of the Arkansas Academy of Science

Interacting dark energy models have been employed to study the behavior of dark energy and matter in the presence of an interaction between the two. One of the successful aspects of these models is how they explain the cosmic coincidence problem. In this work we consider a specific interaction to study the behavior of dark energy and matter through the history of evolution.


Flux Variation Of Cosmic Muons, N. Ramesh, M. Hawron, C. Martin, A. Bachri Jan 2011

Flux Variation Of Cosmic Muons, N. Ramesh, M. Hawron, C. Martin, A. Bachri

Journal of the Arkansas Academy of Science

In the current paper, we analyzed the variation of cosmic radiation flux with elevation, time of the year and ambient temperature with the help of a portable cosmic muon detector, the construction of which was completed by a team from Southern Arkansas University (SAU) at Lawrence Berkeley National Laboratory (LBNL). Cosmic muons and gamma rays traverse two synchronized scintillators connected to two photomultiplier tubes (PMT) via light guides, and generate electronic pulses which we counted using a Data Acquisition Board (DAQ). Because muons are the product of collisions between high-energy cosmic rays and atmospheric nuclei, and therefore shower onto earth, …


New Eclipsing Close Binary Star In The Constellation Of Sextants, Jeff W. Robertson Jan 2009

New Eclipsing Close Binary Star In The Constellation Of Sextants, Jeff W. Robertson

Journal of the Arkansas Academy of Science

No abstract provided.


Taking Another Look: Light N-Capture Element Abundances In Metal-Poor Halo Stars, D. Burris, E. Jones, J. Lusk Jan 2008

Taking Another Look: Light N-Capture Element Abundances In Metal-Poor Halo Stars, D. Burris, E. Jones, J. Lusk

Journal of the Arkansas Academy of Science

Elements are produced in stars through a variety of processes; some are well known, others are still the object of active research. The elements Zirconium (Zr) and Yttrium (Y) are produced via neutron capture (ncapture). These elements reside in the mass range where there is uncertainty about the production mechanism at early time. The rapid n-capture process (r-process) was believed to be responsible for the production, but no study (Burris et al 2000, Gilroy et al 1988 and others) has been able to successfully use the r-process to reproduce the abundance signature for elements in this mass range for metal-poor …


Variational Symmetries And Conservation Laws In Linearized Gravity, Balraj Menon Jan 2006

Variational Symmetries And Conservation Laws In Linearized Gravity, Balraj Menon

Journal of the Arkansas Academy of Science

The methods of symmetry group analysis are applied to the action functional of linearized gravity to derive necessary conditions for the existence of variational symmetries. Two classes of variational symmetries of linearized gravity are discussed, and the local conservation laws associated with these variational symmetries are presented by applying Noether's theorem


New Pulsating Variable Discovered In The Constellation Andromeda, Jeff W. Robertson Jan 2005

New Pulsating Variable Discovered In The Constellation Andromeda, Jeff W. Robertson

Journal of the Arkansas Academy of Science

No abstract provided.


Be Star Spectroscopy Using The Uca Fiber-Fed Spectrograph, Scott Austin Jan 2004

Be Star Spectroscopy Using The Uca Fiber-Fed Spectrograph, Scott Austin

Journal of the Arkansas Academy of Science

Beginning in June 2003, undergraduate students and the author have spectroscopically monitored bright Be stars using a custom built fiber-fed spectrograph attached to the UCA Observatory 11-inch Schmidt-Cassegrain telescope. We have obtained 0.8 Angstrom/pixel resolution spectra of the H-alpha line for over forty Be-Stars. Some have been observed on multiple dates in order to detect any temporal changes. Line profiles, velocities, and observed variations for some of these stars will be presented.


Multi-Phase Transport Study Of Relativistic Nuclear Collisions, Bin Zhang, C. M. Ko, Bao-An Li, Ziwei Lin, Subrata Pal Jan 2001

Multi-Phase Transport Study Of Relativistic Nuclear Collisions, Bin Zhang, C. M. Ko, Bao-An Li, Ziwei Lin, Subrata Pal

Journal of the Arkansas Academy of Science

A multi-phase transport model (AMPT) is developed for the study of hot and dense matter produced in relativistic nuclear collisions. This model includes both initial partonic and final hadronic scattering. Using the AMPT model, we study the momentum distributions of charged particles such as protons, antiprotons, pions, and kaons in central heavy ion collisions at Super Proton Synchrotron (SPS) and Relativistic Heavy Ion Collider (RHIC) energies. The results are consistent with experimental data at these energies. They indicate a significant nuclear shadowing but a relative weak jet quenching in the initial dense matter. Antiproton to proton ratio at mid-rapidity increases …


Estimating Milky-Way Dark Matter: Its Amount And Distribution, Jeffery E. Clayton, Sue Ellen Mccloskey, Wilfred J. Braithwaite Jan 1996

Estimating Milky-Way Dark Matter: Its Amount And Distribution, Jeffery E. Clayton, Sue Ellen Mccloskey, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

No abstract provided.


Creation And Implementation Of A Tracking Module For A Small-Geometry, Vertex Time Projection Chamber, Christine A. Byrd, Wilson H. Howe, Amber D. Climer, Wilfred J. Braithwaite Jan 1995

Creation And Implementation Of A Tracking Module For A Small-Geometry, Vertex Time Projection Chamber, Christine A. Byrd, Wilson H. Howe, Amber D. Climer, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

A charged-particle tracking module was written and tested using pixel data generated from CERN's Monte Carlo detector-modeling program GEANT. This tracking module was customized for testing the design of a micro-strip gas time project chamber, designed by Drs. Margetis and Wieman of the Relativistic Nuclear Collisions Group at Lawrence Berkeley Laboratory. This low-mass, high-resolution, small-geometry vertex time projection chamber was designed for possible use with a larger instrument in an experiment using the relativistic heavy ion collider, RHIC, under construction at Brookhaven National Laboratory in New York. Implementing this tracking module involved generating tables and source code in a manner …


Using Geant To Model Calrimeter Response For Electromagnetic Cascades From Nucleus-Nucleus Interactions In A Cosmic Ray Detector, Kazuhiko Murai, Carlos A. Sanchez, Donald C. Wold Jan 1995

Using Geant To Model Calrimeter Response For Electromagnetic Cascades From Nucleus-Nucleus Interactions In A Cosmic Ray Detector, Kazuhiko Murai, Carlos A. Sanchez, Donald C. Wold

Journal of the Arkansas Academy of Science

Ascintillating optical fiber calorimeter (SOFCAL) is being developed by NASA/Marshall Space Flight Center for use in balloon-borne experiments to study the spectrum of high-energy cosmic rays and gamma rays. SOFCAL will not saturate for long exposures and the calorimeter willbe useful in emulsion chambers to study primary cosmic-ray nuclei with energies from 100 GeV to 1,000 TeV. The event generator FRITIOF was used to model the collision of a cosmic-ray projectile with a target nucleus inan emulsion chamber. The measurements of charged particles from the interaction in the emulsions are related to the energy of the primary cosmic ray nucleus-nucleus …


Using Fritiof To Model Nucleus-Nucleus Interactions In A Cosmic Ray Detector, Carlos A. Sanchez, Kazuhiko Murai, Donald C. Wold Jan 1995

Using Fritiof To Model Nucleus-Nucleus Interactions In A Cosmic Ray Detector, Carlos A. Sanchez, Kazuhiko Murai, Donald C. Wold

Journal of the Arkansas Academy of Science

Ascintillating optical fiber calorimeter (SOFCAL) isbeing developed by NASA/Marshall Space Flight Center for use in experiments to study the spectrum of high-energy cosmic rays and gamma rays from 100 GeV to 1,000 TeV. SOFCAL willnot saturate for long exposures and this calorimeter inthese balloon-borne emulsion chambers willbe helpful for the study of the composition of primary cosmic-ray nuclei. For primary nuclei with energies much greater than 1014 eV, nucleus-nucleus interactions are likely to exhibit characteristics of a quark-gluon plasma (QGP). Aparticle event generator was used tomodel the collision of a cosmic-ray nucleus with a target nucleus inan emulsion chamber. FRITIOF …


Monte Carlo Simulation Of The Scintillating Optical Fiber Calorimeter (Sofcal), Zibin Yang, Russell Gillum, Donald C. Wold Jan 1994

Monte Carlo Simulation Of The Scintillating Optical Fiber Calorimeter (Sofcal), Zibin Yang, Russell Gillum, Donald C. Wold

Journal of the Arkansas Academy of Science

A scintillating optical fiber calorimeter (SOFCAL) is being developed by NASA/Marshall Space Flight Center for use in balloon-borne emulsion chambers to study the spectrum of high-energy cosmic rays and gamma rays. SOFCAL will not saturate for long exposures, and the detector will be helpful for the study of primary cosmic-ray nuclei energies from 100 GeV to 1,000 TeV. For a given incident particle and energy, computer simulations of electromagnetic cascades allow computation of energy deposited in different regions of the calorimeter. For these initial simulations, a 5-cm x 5-cm x 7-cm calorimeter was used. Each subsection contained a 0.4-cm thick …


Monte Carlo Director Modeling And Display, Using The Cern Laboratory, Christine A. Byrd, Charles M. Byrd, Wilfred J. Braithwaite Jan 1993

Monte Carlo Director Modeling And Display, Using The Cern Laboratory, Christine A. Byrd, Charles M. Byrd, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

Detectors for high energy nuclear physics experiments are being modeled using programs developed and maintained at CERN, the European Organization for Nuclear Research. These programs include data handling and display routines, as well as those using random-sampling Monte Carlo techniques to calculate energy depositions for high energy particles as they pass through the various parts of the detector system. The complete CERN library has been imported for use with our Workstation computers in a multiple user environment. The enormous CERN Monte Carlo program GEANT(French for GIANT) tracks the progress of a particle through a detector on a simulated event-by-event basis. …


Time Projection Chamber's Efficiency, Obtained Using Cern's Geant Code, Christine A. Byrd, Charles M. Byrd, Wilfred J. Braithwaite Jan 1993

Time Projection Chamber's Efficiency, Obtained Using Cern's Geant Code, Christine A. Byrd, Charles M. Byrd, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

Geometrical acceptance and reconstruction of tracks have been carried out for a Time Projection Chamber (TPC) used in Experiment NA35: the 35th experiment in the North Area of the Super Proton Synchrotron (SPS), located at the European Organization for Nuclear Research (CERN). NA35 used the SPS at CERN to produce 6.4 TeV beams of 32S for central collisions with Au nuclei. The TPC modeling effort used a modified version of CERN's Monte Carlo program GEANT, which simulates the response of the NA35 TPC to output from CERN's primary event generators. GEANT was used to simulate three-dimensional pixel data in the …


Pole Stars Of Other Planets, Paul C. Sharrah Jan 1975

Pole Stars Of Other Planets, Paul C. Sharrah

Journal of the Arkansas Academy of Science

The north celestial pole of the Earth and the other planets is discussed. Right ascension and declination information on the location of the poles on the celestial sphere is summarized. The name of the brightest visible star near each pole is given and the special case of Uranus is discussed.


Twenty Years Of Experience With The University Of Arkansas Planetarium, Paul C. Sharrah Jan 1974

Twenty Years Of Experience With The University Of Arkansas Planetarium, Paul C. Sharrah

Journal of the Arkansas Academy of Science

The Model A-1 Spitz planetarium was placed in operation at the University of Arkansas in 1954. It was moved to its present location in 1972 and has continued to have a much expanded use. More than 8,000 persons attended demonstrations between 1 August 1972 and 31 March 1974. Approximately one third of these were University students in classes and laboratories; the remaining two thirds were accounted for by school and other youth groups and the public demonstrations.