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2003

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Articles 91 - 120 of 135

Full-Text Articles in Astrophysics and Astronomy

A Dearth Of Dark Matter In Ordinary Elliptical Galaxies, Aaron J. Romanowsky, N. G. Douglas, M. Arnaboldi, K. Kuijken, M. R. Merrifield, N. R. Napolitano, M. Capaccioli Jan 2003

A Dearth Of Dark Matter In Ordinary Elliptical Galaxies, Aaron J. Romanowsky, N. G. Douglas, M. Arnaboldi, K. Kuijken, M. R. Merrifield, N. R. Napolitano, M. Capaccioli

Faculty Publications

The kinematics of the outer parts of three intermediate-luminosity elliptical galaxies were studied with the Planetary Nebula Spectrograph. The galaxies' velocity-dispersion profiles were found to decline with the radius, and dynamical modeling of the data indicates the presence of little if any dark matter in these galaxies' halos. This unexpected result conflicts with findings in other galaxy types and poses a challenge to current galaxy formation theories.

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Seven New Keck Planets Orbiting G And K Dwarfs, R. Paul Butler, Geoffrey W. Marcy, Steve S. Vogt, Debra A. Fischer, Gregory W. Henry, Gregory Laughlin, Jason Wright Jan 2003

Seven New Keck Planets Orbiting G And K Dwarfs, R. Paul Butler, Geoffrey W. Marcy, Steve S. Vogt, Debra A. Fischer, Gregory W. Henry, Gregory Laughlin, Jason Wright

Information Systems and Engineering Management Research Publications

Planetary mass companions orbiting seven nearby G and K dwarfs have been found from the Keck Precision Doppler Survey. A "51 Peg-like" planet orbiting HD 49674 has the smallest mass yet found, M sin i = 0.12 MJ. This system does not transit. A double-planet system orbits HD 37124, with periods of 153 days and 6 yr and minimum masses of 0.91 and 1.70 MJ. Single companions with moderate eccentricity have been found orbiting HD 108874, HD 72659, HD 114729, and HD 145675 with orbital periods ranging from 1.09 to 5.98 yr, yielding minimum masses ranging …

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Multiperiodicity In Five Small‐Amplitude Pulsating Red Giants, John R. Percy, Gurtina Besla, Vince Velocci, Gregory W. Henry Jan 2003

Multiperiodicity In Five Small‐Amplitude Pulsating Red Giants, John R. Percy, Gurtina Besla, Vince Velocci, Gregory W. Henry

Information Systems and Engineering Management Research Publications

We report multiperiodicity in five small‐amplitude pulsating red giants: RZ Ari, V523 Mon, BC CMi, UX Lyn, and FS Com. For each of these stars, two or three periods recur in each season of our 5000 day database of V observations. The periods and their ratios are consistent with low‐order radial pulsation modes. The amplitudes of the modes change significantly on timescales of 1–5 yr; specifically, the amplitudes of the dominant periods vary on timescales of 2000–3500 days. Most often, the amplitudes of the modes in a given star rise and fall in unison.

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A Sub-Saturn Mass Planet Orbiting Hd 3651, Debra A. Fischer, R. Paul Butler, Geoffrey W. Marcy, Steve Vogt, Gregory W. Henry Jan 2003

A Sub-Saturn Mass Planet Orbiting Hd 3651, Debra A. Fischer, R. Paul Butler, Geoffrey W. Marcy, Steve Vogt, Gregory W. Henry

Information Systems and Engineering Management Research Publications

We report precise Doppler velocities of HD 3651 obtained at Lick and Keck Observatories. The velocities reveal evidence of a planetary companion with an orbital period of 62.23 ± 0.03 days, an eccentricity of 0.63 ± 0.04, and a velocity semiamplitude of 15.9 ± 1.7 m s-1. With an assumed mass of 0.79 M☉ for this K0 V star, we derive M sin i = 0.20MJ and a semimajor axis of 0.284 AU. The star is chromospherically inactive, with log R = -5.01, and 10 years of observations at Fairborn Observatory show it to be …

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A Dozen New Γ Doradus Stars, Gregory W. Henry, Francis C. Fekel Jan 2003

A Dozen New Γ Doradus Stars, Gregory W. Henry, Francis C. Fekel

Information Systems and Engineering Management Research Publications

We use new high-dispersion spectroscopic and precise photometric observations to identify 12 new γ Doradus stars. Two of the 12 systems are double-lined binaries that show obvious velocity variability. Five other stars have metallic lines with composite profiles characterized by a narrow feature near the center of each broad component. Spectrograms of the Hα line indicate that all five stars are binaries rather than shell stars. The remaining five stars in our sample are probably single. All 12 stars are photometrically variable with amplitudes between 6 and 87 mmag in Johnson B and periods between 0.3 and 1.2 days. Four …

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A Planetary Companion To Hd 40979 And Additional Planets Orbiting Hd 12661 And Hd 38529, Debra A. Fischer, Geoffrey W. Marcy, R. Paul Butler, Steve Vogt, Gregory W. Henry, Dimitri Pourbaix, Bernard Walp, Anthony A. Misch, Jason T. Wright Jan 2003

A Planetary Companion To Hd 40979 And Additional Planets Orbiting Hd 12661 And Hd 38529, Debra A. Fischer, Geoffrey W. Marcy, R. Paul Butler, Steve Vogt, Gregory W. Henry, Dimitri Pourbaix, Bernard Walp, Anthony A. Misch, Jason T. Wright

Information Systems and Engineering Management Research Publications

We report the detection of three extrasolar planets from the Lick and Keck observatories. The F8 V star HD 40979 has a companion with orbital period P = 263.1 ± 3 days, eccentricity e = 0.25 ± 0.05, and velocity semiamplitude K = 101.2 ± 5.6 m s-1. The inferred semimajor axis is 0.83 AU and M sin i = 3.28MJup. Observations of planetary companions orbiting the G6 V star HD 12661 and the G4 IV star HD 38529 have already been published, and here we report additional, longer period companions for both of these stars. The outer companion to …

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Feedback From The First Supernovae In Protogalaxies: The Fate Of The Generated Metals, Keiichi Wada, Aparna Venkatesan Jan 2003

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. …

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Evolving Spectra Of Population Iii Stars: Consequences For Cosmological Reionization, Aparna Venkatesan, Jason Tumlinson, J Shull Jan 2003

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. …

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Cosmological Effects Of The First Stars: Evolving Spectra Of Population Iii, Jason Tumlinson, J Shull, Aparna Venkatesan Jan 2003

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 …

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Lisa, Binary Stars, And The Mass Of The Graviton, Curt Cutler, William A. Hiscock, Shane L. Larson Jan 2003

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 mg by comparing the arrival times of gravitational and electromagnetic signals from binary star systems. We show that the best possible limit on mg 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 …

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Inverted Velocity Profile In The Cylindrical Couette Flow Of A Rarefied Gas, Alejandro Garcia, K. Aoki, H. Yoshida, T. Nakanishi Jan 2003

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 …

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Properties Of High-Latitude Cme-Driven Disturbances During Ulysses Second Northern Polar Passage, Daniel B. Reisenfeld, J. T. Gosling, R. J. Forsyth, P. Riley, O. C. St. Cyr Jan 2003

Properties Of High-Latitude Cme-Driven Disturbances During Ulysses Second Northern Polar Passage, Daniel B. Reisenfeld, J. T. Gosling, R. J. Forsyth, P. Riley, O. C. St. Cyr

Physics and Astronomy Faculty Publications

Ulysses observed five coronal mass ejections (CMEs) and their associated disturbances while the spacecraft was immersed in the polar coronal hole (CH) flow above 70° N in late 2001. Of these CMEs, two were very fast (>850 km s−1) driving strong shocks in the wind ahead, and two others were over-expanding. The two fast CMEs were observed leaving the Sun by LASCO/SOHO, and were observed in the ecliptic by Genesis and ACE. These were large events, spanning at least from the northern heliospheric pole to the ecliptic. One-dimensional hydrodynamic simulations indicate that these could be described as …

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The Development Of Grape, A Gamma Ray Polarimeter Experiment, Mark L. Mcconnell, J Ledoux, John R. Macri, James M. Ryan Jan 2003

The Development Of Grape, A Gamma Ray Polarimeter Experiment, Mark L. Mcconnell, J Ledoux, John R. Macri, James M. Ryan

Space Science Center

The measurement of hard X‐ray polarization in γ‐ray bursts (GRBs) would add yet another piece of information in our effort to resolve the true nature of these enigmatic objects. Here we report on the development of a dedicated polarimeter design with a relatively large FoV that is capable of studying hard X‐ray polarization (50–300 keV) from GRBs. This compact design, based on the use of a large area position‐sensitive PMT (PSPMT), is referred to as GRAPE (Gamma‐RAy Polarimeter Experiment). The feature of GRAPE that is especially attractive for studies of GRBs is the significant off‐axis polarization response (at angles greater …

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Lisa Data Analysis: Source Identification And Subtraction, Neil J. Cornish, Shane L. Larson Jan 2003

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.

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Sedimentological And Plant Taphonomic Evaluation Of The Early Middle Devonian Trout Valley Formation, Jonathan Allen Jan 2003

Sedimentological And Plant Taphonomic Evaluation Of The Early Middle Devonian Trout Valley Formation, Jonathan Allen

Honors Theses

The Trout Valley Formation of Emsian-Eifelian age, outcropped in Baxter State Park, Maine, consists offluvial and coastal deposits preserving early land plants. Massive, crudely bedded conglomerate represents deposits of proximal braided channels on an alluvial fan complex. Lithic sandstone bodies in channel-form geometries represent deposits of river channels draining the Acadian highlands whereas associated siltstones represent overbank deposits, intertidal flats, and tidal channels. Localized lenticular quartz arenites represent nearshore shelf bar deposits that were storm influenced. The majority of plant assemblages preserved mainly in siltstone lithologies are allochthonous and parautochthonous, with only one autochthonous assemblage identified in the sequence. Plant …

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The Everchanging Pulsating White Dwarf Gd358, Souza Oliveira Kepler, Matt A. Wood, Nicole M. Silvestri, Thomas J. Ahrens Jan 2003

The Everchanging Pulsating White Dwarf Gd358, Souza Oliveira Kepler, Matt A. Wood, Nicole M. Silvestri, Thomas J. Ahrens

Aerospace, Physics, and Space Science Faculty Publications

We report 323 hours of nearly uninterrupted time series photometric observations of the DBV star GD 358 acquired with the Whole Earth Telescope (WET) during May 23rd to June 8th, 2000. We acquired more than 232 000 independent measurements. We also report on 48 hours of time-series photometric observations in Aug 1996. We detected the non-radial g-modes consistent with degree ℓ = 1 and radial order 8 to 20 and their linear combinations up to 6th order. We also detect, for the first time, a high amplitude ℓ = 2 mode, with a period of 796 s. In the 2000 …

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2mass J0516288+260738: Discovery Of The First Eclipsing Late K + Brown Dwarf Binary System?, Sonja L. Schüh, Matt A. Wood Jan 2003

2mass J0516288+260738: Discovery Of The First Eclipsing Late K + Brown Dwarf Binary System?, Sonja L. Schüh, Matt A. Wood

Aerospace, Physics, and Space Science Faculty Publications

We report the discovery of a new eclipsing system less than one arcminute south of the pulsating DB white dwarf KUV 05134+2605 . The object could be identified with the point source 2MASS J0516288+260738 published by the Two Micron All Sky Survey. We present and discuss the first light curves as well as some additional colour and spectral information. The eclipse period of the system is 1.29 d, and, assuming this to be identical to the orbital period, the best light curve solution yields a mass ratio of m₂/m₁=0.11, a radius ratio of r₂/r₁ ≈ 1 and an inclination of …

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Multisite Observations Of The Pms Δ Scuti Star V351 Ori, Vincenzo Ripepi, T D. Oswalt, Mark J. Rudkin, Kyle B. Johnston Jan 2003

Multisite Observations Of The Pms Δ Scuti Star V351 Ori, Vincenzo Ripepi, T D. Oswalt, Mark J. Rudkin, Kyle B. Johnston

Aerospace, Physics, and Space Science Faculty Publications

We present the results of multisite observations spanning two years on the pre-main-sequence (PMS) star V351 Ori. A total of around 180 hours of observations over 29 nights have been collected, allowing us to measure five different periodicities, most likely related to the δ Scuti variability of V351 Ori. Comparison with the predictions of linear nonadiabatic radial pulsation models put stringent constraints on the stellar parameters and indicate that the distance to V351 Ori is intermediate between the lower limit measured by Hipparcos (210 pc) and that of the Orion Nebula (450 pc). However, radial pulsation models are unable to …

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Ulysses Cospin Observations Of Cosmic Rays And Solar Energetic Particles From The South Pole To The North Pole Of The Sun During Solar Maximum, Robert Bruce Mckibben, Ming Zhang Jan 2003

Ulysses Cospin Observations Of Cosmic Rays And Solar Energetic Particles From The South Pole To The North Pole Of The Sun During Solar Maximum, Robert Bruce Mckibben, Ming Zhang

Aerospace, Physics, and Space Science Faculty Publications

In 2000–2001 Ulysses passed from the south to the north polar regions of the Sun in the inner heliosphere, providing a snapshot of the latitudinal structure of cosmic ray modulation and solar energetic particle populations during a period near solar maximum. Observations from the COSPIN suite of energetic charged particle telescopes show that latitude variations in the cosmic ray intensity in the inner heliosphere are nearly non-existent near solar maximum, whereas small but clear latitude gradients were observed during the similar phase of Ulysses’ orbit near the 1994–95 solar minimum. At proton energies above ∼10 MeV and extending up to …

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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 Jan 2003

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 (Te) and the fractional mean-square Te variation (t2A)across the nebula. We also measure the intrinsic line ratio [N II] 5756/6585 in order to estimate Te and t2A 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 …

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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 Jan 2003

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 …

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Table Of Contents Jan 2003

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

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President's Message Jan 2003

President's Message

Journal of the South Carolina Academy of Science

No abstract provided.

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Histological Effect Of Ascocotyle Tenuicollis (Digenea: Heterophyidae) Metacercarial Infection On The Heart Of Fundulus Heteroclitus (Teleostei: Cyprinodontidae), Toni Hicks, Edna Steele Jan 2003

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.

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Par Mediation Of Thrombin-Induced Effects On Motoneurons, Nadim Salman, Drew Watkins, Kate Hamel, Lakisha Gadsden, Sarah Funderburk, Victoria Turgeon Jan 2003

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.

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Embryogenesis In The Japanese Medaka, Oryzias Latipes, Laura Harris Harris, Lisa Sims, Roxann Stachiw Jan 2003

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.

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2002 & 2003 Annual Meeting Extended Abstracts Jan 2003

2002 & 2003 Annual Meeting Extended Abstracts

Journal of the South Carolina Academy of Science

No abstract provided.

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South Carolina Statewide Science Safety Project., Linda Sinclair, Jack Gerlovich, Rahul A. Parsa Jan 2003

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

Journal of the South Carolina Academy of Science

No abstract provided.

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Some Notes On Multiplicative Congruential Random Number Generators With Mersenne Prime Modulus 261-1., James Harris Jan 2003

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.

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Maternal And Sibling Influences On Seed Germination Of Aegilops Triuncialis Erin, Erin Scott, Andrew R. Dyer Jan 2003

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.

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