Astrophysics and Astronomy Commons^™

Feedback From The First Supernovae In Protogalaxies: The Fate Of The Generated Metals, Keiichi Wada, Aparna Venkatesan

Physics and Astronomy

We investigate the chemo-dynamical effects of multiple supernova explosions in the central region of primordial galaxies using three-dimensional hydrodynamical simulations of the inhomogenous interstellar medium down to parsec-scales. We find that the final protogalactic structure and metal distribution depend strongly on the number of SNe. Specifically, 1) 1000 SNe after an instantaneous burst of star formation are sufficient to almost completely blow away the gas in these systems, whereas 2) 100 SN explosions trigger the collapse of the protogalactic cloud, leading to the formation of a cold, dense clumpy disk (n > 300 cm^-3) with metallicity, Z = 4 10^-4 Z_sun. …

Evolving Spectra Of Population Iii Stars: Consequences For Cosmological Reionization, Aparna Venkatesan, Jason Tumlinson, J Shull

Physics and Astronomy

We examine the significance of the first metal-free stars (Population III) for the cosmological reionization of H I and He II. These stars have unusually hard spectra, with the integrated ionizing photon rates from a Population III stellar cluster for H I and He II being 1.6 and 10⁵ times stronger, respectively, than those from a Population II cluster. For the currently favored cosmology, we find that Population III stars alone can reionize H I at redshifts of z 9 and 4.7 and He II at z 5.1 and 0.7 for continuous and instantaneous modes of star formation, respectively. …

Cosmological Effects Of The First Stars: Evolving Spectra Of Population Iii, Jason Tumlinson, J Shull, Aparna Venkatesan

Physics and Astronomy

The first stars hold intrinsic interest for their uniqueness and for their potentially important contributions to galaxy formation, chemical enrichment, and feedback on the intergalactic medium (IGM). Although the sources of cosmological reionization are unknown at present, the declining population of large bright quasars at redshifts z > 3 implies that stars are the leading candidates for the sources that reionized the hydrogen in the IGM by z ~ 6. The metal-free composition of the first stars restricts the stellar energy source to proton-proton burning rather than the more efficient CNO cycle. Consequently, they are hotter, smaller, and have harder spectra …

Lisa, Binary Stars, And The Mass Of The Graviton, Curt Cutler, William A. Hiscock, Shane L. Larson

All Physics Faculty Publications

We extend and improve earlier estimates of the ability of the proposed LISA (Laser Interferometer Space Antenna) gravitational wave detector to place upper bounds on the graviton mass m_g by comparing the arrival times of gravitational and electromagnetic signals from binary star systems. We show that the best possible limit on m_g obtainable this way is ∼50 times better than the current limit set by solar system measurements. Among currently known, well-understood binaries, 4U1820-30 is the best for this purpose; LISA observations of 4U1820-30 should yield a limit ≈3-4 times better than the present solar system bound. AM …

Inverted Velocity Profile In The Cylindrical Couette Flow Of A Rarefied Gas, Alejandro Garcia, K. Aoki, H. Yoshida, T. Nakanishi

Faculty Publications

The cylindrical Couette flow of a rarefied gas is investigated, under the diffuse-specular reflection condition of Maxwell’s type on the cylinders, in the case where the inner cylinder is rotating whereas the outer cylinder is at rest. The inverted velocity profile for small accommodation coefficients, pointed out by Tibbs, Baras, and Garcia [Phys. Rev. E 56, 2282 (1997)] on the basis of a Monte Carlo simulation, is investigated extensively by means of a systematic asymptotic analysis for small Knudsen numbers as well as the direct numerical analysis of the Boltzmann equation, and the parameter range in which the phenomenon appears …

Lisa Data Analysis: Source Identification And Subtraction, Neil J. Cornish, Shane L. Larson

All Physics Faculty Publications

The Laser Interferometer Space Antenna will operate as an AM-FM receiver for gravitational waves. For binary systems, the source location, orientation and orbital phase are encoded in the amplitude and frequency modulation. The same modulations spread a monochromatic signal over a range of frequencies, making it difficult to identify individual sources. We present a method for detecting and subtracting individual binary signals from a data stream with many overlapping signals.

Temperature Variations From Hubble Space Telescope Spectroscopy Of The Orion Nebula, R. H. Rubin, P. G. Martin, R. J. Dufour, Gary J. Ferland, K. P. M. Blagrave, X.-W. Liu, J. F. Nguyen, J. A. Baldwin

Physics and Astronomy Faculty Publications

We present Hubble Space Telescope (HST)/STIS long-slit spectroscopy of NGC 1976. Our goal is to measure the intrinsic line ratio [O III] 4364/5008 and thereby evaluate the electron temperature (T_e) and the fractional mean-square T_e variation (t²_A)across the nebula. We also measure the intrinsic line ratio [N II] 5756/6585 in order to estimate T_e and t²_A in the N⁺region. The interpretation of the [N II] data is not as clear cut as the [O III] data because of a higher sensitivity to knowledge …

Inner-Shell Photoexcitation Of Fe Xv And Fe Xvi, R. Kisielius, A. Hibbert, Gary J. Ferland, M. E. Foord, S. J. Rose, P. A. M. Vanhoof, F. P. Keenan

Physics and Astronomy Faculty Publications

The configuration-interaction method as implemented in the computer code CIV3 is used to determine energy levels, electric dipole radiative transition wavelengths, oscillator strengths and transition probabilities for inner-shell excitation of transitions in Fe XV and Fe XVI. Specifically, transitions are considered of the type 1s²2s²2p⁶3s²–1s²2s²2p⁵3l3l′3l′′ (l, l′ and l′′= s, p or d) in Fe XV and 1s²2s²2p⁶3s–1s²2s²2p⁵3l3l′ (l …

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

President's Message

Journal of the South Carolina Academy of Science

No abstract provided.

Histological Effect Of Ascocotyle Tenuicollis (Digenea: Heterophyidae) Metacercarial Infection On The Heart Of Fundulus Heteroclitus (Teleostei: Cyprinodontidae), Toni Hicks, Edna Steele

Journal of the South Carolina Academy of Science

No abstract provided.

Par Mediation Of Thrombin-Induced Effects On Motoneurons, Nadim Salman, Drew Watkins, Kate Hamel, Lakisha Gadsden, Sarah Funderburk, Victoria Turgeon

Journal of the South Carolina Academy of Science

No abstract provided.

Embryogenesis In The Japanese Medaka, Oryzias Latipes, Laura Harris Harris, Lisa Sims, Roxann Stachiw

Journal of the South Carolina Academy of Science

No abstract provided.

2002 & 2003 Annual Meeting Extended Abstracts

Journal of the South Carolina Academy of Science

No abstract provided.

South Carolina Statewide Science Safety Project., Linda Sinclair, Jack Gerlovich, Rahul A. Parsa

Journal of the South Carolina Academy of Science

No abstract provided.

Some Notes On Multiplicative Congruential Random Number Generators With Mersenne Prime Modulus 261-1., James Harris

Journal of the South Carolina Academy of Science

No abstract provided.

Maternal And Sibling Influences On Seed Germination Of Aegilops Triuncialis Erin, Erin Scott, Andrew R. Dyer

Journal of the South Carolina Academy of Science

No abstract provided.

Scas Officers And Council Members 2003 - 2004

Journal of the South Carolina Academy of Science

No abstract provided.

Critical Thinking And Biology Instruction., David J. Stroup, John L. Frola

Journal of the South Carolina Academy of Science

No abstract provided.

Trace Analysis Of Organic Substances, Alan Giltinan

Theses

One of the major challenges facing the pharmaceutical industry is the control of the amount of trace contaminants during the manufacture of organic substances. Lowering the level of contamination improves the quality of the product and reduces possible side effects.

One of the main techniques used to detect trace contaminants is UV-VIS spectroscopy, where the unique absorption fingerprint of a chemical reveals its presence. UV-VIS absorption is based upon the Beer-Lambert Law. The critical point to note about this law is that the absorption is exponentially dependent on both the concentration of the absorber and the pathlength traversed by the …

Low-Flow Helmholtz Resonator For Molar Mass Detection, Brackman Amy, Amanda Kea, Kenneth Mcgill

The Corinthian

A simple apparatus was constructed for an undergraduate physical chemistry laboratory to determine a mathematical model of wavelike motion. The apparatus was assembled by attaching an airflow valve connected to a tank of argon gas to a GC column, thus creating regulated airflow. The air was manipulated to gently flow over a small sensitive microphone that was attached to an inexpensive resonator. A model will be developed to measure the speed of sound that will lead to the measurement of the molar mass.

Precision Measurement Of The Proton And Deuteron Spin Structure Functions G2 And Asymmetries A2, P. L. Anthony, R. G. Arnold, T. Averett, H. R. Band, N. Benmouna, W. Boeglin, H. Borel, P. E. Bosted, S. L. Bültmann, G. R. Court, C. E. Hyde-Wright, S. E. Kuhn, F. Sabatie, F. R. Wesselmann

Physics Faculty Publications

We have measured the spin struction functions g2(p) and g(2)(d) and the virtual photon asymmetries A(2)(p) and A(2)(d) over the kinetmatic range 0.02 less than or equal to x less than or equal to 0.8 and 0.7 less than or equal to Q² less than or equal to 20 GeV2 by scattering 29.1 and 32.3 GeV longitudinally polarized electrons from transversely polarized NH3 and (LiD)-Li-6 targets. Our measured g² approximately follows the twist-2 Wandzura-Wilczek calculation. The twist-3 reduced matrix elements d(2)(p) and d(2)(n) are less than two standard deviations from zero. The data are inconsistent with the Burkhardt-Cottingham …

The Neutron Charge Form Factor And Target Analyzing Powers From 3He (E→, E 'N) Scattering, J. Bermuth, P. Merle, C. Carasco, D. Baumann, R. Böhm, D. Bosnar, M. Ding, M. O. Distler, J. Friedrich, A. Klein

Physics Faculty Publications

The charge form factor of the neutron has been determined from asymmetries measured in quasi-elastic ³He(e→, e 'n) at a momentum transfer of 0.67 (GeV/c)². In addition, the target analyzing power, Ayo has been measured to study effects of final state interactions and mespn exchange currents.

Final State Interaction Effects In 3He (E→, E' P), C. Carasco, J. Bermuth, P. Merle, P. Bartsch, D. Baumann, R. Böhm, D. Bosnar, M. Ding, M. O. Distler, A. Klein

Physics Faculty Publications

Asymmetries in quasi-elastic ³He(e→, e 'p) have been measured at a momentum transfer of 0.67 (GeV/c)² and are compared to a calculation which takes into account relativistic kinematics in the final state and a relativistic one-body current operator. With an exact solution of the Faddeev equation for the ³He-ground state and an approximate treatment offinal state interactions in the continuum good agreement is found with the experimental data.

Spontaneous Magnetization Generated By Spin, Pulsating, And Planar Combustion Synthesis, Karen S. Martirosyan, J. R. Claycomb, G. Gogoshin, R. A. Yarbrough, J. H. Miller Jr., D. Luss

Physics & Astronomy Faculty Publications

The motion of the high temperature front during combustion synthesis of ferrite materials generates residual magnetization in cylindrical product samples. The combustion wave created a current density of up to 10 A/cm2, which influenced the magnetization distribution. The measured peak magnetic field intensity was up to 8 mT. Qualitatively different magnetic field maps were generated in ferrite samples synthesized by different combustion modes. The average magnetization vector generated by either planar or pulsating combustion was oriented at a smaller angle with respect to the pellet axis ~f<45°! than those generated by spin combustion ~60°

Mode-Cleaning And Injection Optics Of The Gravitational-Wave Detector Geo600, S. Goßler, M. M. Casey, A. Grant, H. Grote, Volker Quetschke

Physics & Astronomy Faculty Publications

The British–German interferometric gravitational-wave detector GEO600 uses two high-finesse triangular ring cavities of 8 m optical pathlength each, as an optical mode-cleaning system. The modecleaner system is housed in an ultrahigh-vacuum environment to avoid contamination of the optics and to minimize both the influence of refractive index variations of the air and acoustic coupling to the optics. To isolate the cavities from seismic noise, all optical components are suspended as double pendulums. These pendulums are damped at their resonance frequencies at the upper pendulum stage with magnet-coil actuators. A suspended reaction mass supports three coils matching magnets bonded onto the …

Comment On ‘‘Why Is The Dna Denaturation Transition First Order?’’, Andreas Hanke, Ralf Metzler

Physics & Astronomy Faculty Publications

A Comment on the Letter by . The authors of the Letter offer a Reply.

Measurement Of The Stochasticity Of Low-Latitude Geomagnetic Temporal Variations, Mark Anthony Reynolds, James A. Wanliss

Publications

Ground magnetometer measurements of total magnetic field strength from 6 stations at low latitudes were analyzed using power spectrum and Hurst range scaling techniques. The Hurst exponents for most of these time-series were near 0.5, which indicates stochasticity, with the highest latitude stations exhibiting some persistence with Hurst exponents greater than 0.6. Although no definite correlations are evident, the relative increase of the Hurst exponent with latitude suggests the possibility that the underlying dynamics of the magnetosphere change with latitude. This result may help quantify the dynamics of the inner magnetosphere itself without the direct presence of the solar wind …

He Ii Reverberation In Active Galactic Nucleus Spectra, Mark C. Bottorff, Jack A. Baldwin, Gary J. Ferland, Jason W. Ferguson, Kirk T. Korista

Physics and Astronomy Faculty Publications

This paper compares the observed reverberation response lags and the intensity ratios of the broad-line region (BLR) emission lines He II λ1640, He II λ4686, and C IV λ1549 with predictions. Published observations indicate that the He II λ1640 lag is 3 times shorter than the lags of He II λ4686 or C IV λ1549. Diverse models, however, do not reproduce this observation. Extensive improved numerical simulations of the hydrogenic isoelectronic sequence emission show that the He II spectrum remains especially simple, even in the central regions of a luminous quasar. Line trapping never builds up a significant population of …

Controlling Laser High-Order Harmonic Generation Using Weak Counter-Propagating Light, Sergei Leonidovich Voronov

Theses and Dissertations

Laser high-order harmonic generation in the presence of relatively weak interfering light is investigated. The interfering pulses intersect the primary harmonic-generating laser pulse at the laser focus. The interfering light creates a standing intensity and phase modulation on the field, which disrupts microscopic phase matching and shuts down local high harmonic production. Suppression of the 23rd harmonic (by two orders of magnitude) is observed when a counter-propagating interfering pulse of light is introduced. A sequence of counter-propagating pulses can be used to shut down harmonic production in out-of-phase zones of the generating volume to achieve quasi phase matching. Harmonic emission …