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The Initial-Final Mass Relationship: Spectroscopy Of White Dwarfs In Ngc 2099 (M37), Jasonjot Singh Kalirai, Ted Von Hippel, Et Al. Dec 2004

The Initial-Final Mass Relationship: Spectroscopy Of White Dwarfs In Ngc 2099 (M37), Jasonjot Singh Kalirai, Ted Von Hippel, Et Al.

Publications

We present new observations of very faint white dwarfs (WDs) in the rich open star cluster NGC 2099 (M37). Following deep, wide-field imaging of the cluster using the Canada-France-Hawaii Telescope, we have now obtained spectroscopic observations of candidate WDs using both the Gemini Multi-Object Spectrograph on Gemini North and the Low-Resolution Imaging Spectrometer on Keck. Of our 24 WD candidates (all fainter than V = 22.4), 21 are spectroscopically confirmed to be bona fide WDs, four or five of which are most likely field objects. Fitting 18 of the 21 WD spectra with model atmospheres, we find that most WDs …

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Discovery Of Co Gas In The Inner Disk Of Tw Hydrae, Terrence W. Rettig, Joe Haywood, Theodore Simon, Sean D. Brittain, Erika Gibb Dec 2004

Discovery Of Co Gas In The Inner Disk Of Tw Hydrae, Terrence W. Rettig, Joe Haywood, Theodore Simon, Sean D. Brittain, Erika Gibb

Publications

We report the detection of rovibrationally excited CO emission from the inner disk of the classical T Tauri star (cTTS) TW Hya. We observe ~6 × 1021 g of CO gas with a rotational temperature of 430 ± 40 K. The linearity of the excitation plot suggests that the CO is optically thin. Atypical for cTTSs, hot CO was not detected, implying that TW Hya has cleared its inner disk region out to a radial distance of ~0.5 AU. We discuss implications for the structure of the disk as it relates to replenishment and planet formation.

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Alkali-Activity Correlations In Open Clusters, Jeremy R. King, Simon C. Schuler Dec 2004

Alkali-Activity Correlations In Open Clusters, Jeremy R. King, Simon C. Schuler

Publications

We present a census of correlations between activity measures and neutral resonance lines of the alkali elements Li i and K i in open clusters and star-forming regions. The majority of very young associations and star formation regions show no evidence of Li-activity correlations, perhaps because their chromospheric activity indicators have a dominant origin in accretion processes with implied disk-clearing timescales in the range of a few times 106 to $4 ;107 yr. Alkali-alkali and/or alkali-activity correlations are newly noted within IC 2391, M34, and perhaps Blanco 1 and NGC 6475. Global X-ray luminosities are not as robust indicators as …

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Juju And Justice At The Movies: Vigilantes In Nigerian Popular Videos, John C. Mccall Dec 2004

Juju And Justice At The Movies: Vigilantes In Nigerian Popular Videos, John C. Mccall

Publications

This article examines the rise of vigilantism in southeastern Nigeria. Two opposing discourses on Nigerian vigilantism are examined. The first is characterized by the valorization of vigilantes as heroes in popular Nigerian video movies. The second is represented by a recent Human Rights Watch (HRW) report denouncing the vigilantes as criminals. My research utilizes ethnographic research to contextualize the video movies as a means toward understanding the ideological gap between these discourses. A close analysis of the Issakaba video series reveals a subtle treatment of the vigilante phenomenon designed to appeal to an indigenous perspective that is cognizant of the …

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Coordinate Conditions For A Uniformly Accelerated Or Static Plane Symmetric Metric, Preston Jones, Lucas Wanex Dec 2004

Coordinate Conditions For A Uniformly Accelerated Or Static Plane Symmetric Metric, Preston Jones, Lucas Wanex

Publications

The coordinate conditions for three exact solutions for the metric components of a coordinate system with constant acceleration or of a static plane symmetric gravitational field are presented. First, the coordinate condition that the acceleration of light is constant is applied to the field equations to derive the metric of a coordinate system of constant acceleration. Second, the coordinate conditions required to produce the metrics of Rindler and Lass are applied to the field equations to calculate the components of these two metrics and the coordinate velocities and coordinate accelerations for light of these two metrics are compared to the …

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Probing A Grb Progenitor At A Redshift Of Z=2: A Comprehensive Observing Campaign Of The Afterglow Of Grb 030226, S. Klose, J. Greiner, A. Rau, A. A. Henden, Dieter H. Hartmann, A. Zeh, C. Reis, N. Masetti, D. Malesani, E. Guenther Nov 2004

Probing A Grb Progenitor At A Redshift Of Z=2: A Comprehensive Observing Campaign Of The Afterglow Of Grb 030226, S. Klose, J. Greiner, A. Rau, A. A. Henden, Dieter H. Hartmann, A. Zeh, C. Reis, N. Masetti, D. Malesani, E. Guenther

Publications

We report results from a comprehensive follow-up observing campaign of the afterglow of GRB 030226, in-cluding VLTspectroscopy, VLT polarimetry, and Chandra X-ray observations. In addition, we present BOOTES-1 wide-field observations at the time of the occurrence of the burst. First observations at ESO started 0.2 days after the event when the gamma ray burst (GRB) afterglow was at a magnitude of R $19 and continued until the afterglow had faded below the detection threshold (R > 26). No underlying host galaxy was found. The optical light curve shows a break around 0.8 days after the burst, which is achromatic within the …

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Simultaneous Identification And Correction Of Systematic Error In Bioenergetics Models: Demonstration With A White Crappie (Pomoxis Annularis) Model, Przemyslaw G. Bajer, Robert S. Hayward, Gregory W. Whitledge, Richard D. Zweifel Nov 2004

Simultaneous Identification And Correction Of Systematic Error In Bioenergetics Models: Demonstration With A White Crappie (Pomoxis Annularis) Model, Przemyslaw G. Bajer, Robert S. Hayward, Gregory W. Whitledge, Richard D. Zweifel

Publications

Recent evidence indicates that important systematic error exists in many fish bioenergetics models (BEMs). An approach for identifying and correcting this error is demonstrated with a white crappie (Pomoxis annularis) BEM. Model-predicted trajectories of growth and cumulative consumption for 39 individual white crappie obtained from six 60-day laboratory experiments diverged from observed values by up to 42.5% and 227%, respectively, indicating systematic error in the BEM. To evaluate correlates of the systematic error, model prediction errors were regressed against three major input/output variables of BEMs that were covered by the laboratory experiments: fish body weight (80–341 g), temperature …

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Widespread Consumption-Dependent Systematic Error In Fish Bioenergetics Models And Its Implications, Przemyslaw G. Bajer, Gregory W. Whitledge, Robert S. Hayward Nov 2004

Widespread Consumption-Dependent Systematic Error In Fish Bioenergetics Models And Its Implications, Przemyslaw G. Bajer, Gregory W. Whitledge, Robert S. Hayward

Publications

Data from laboratory evaluations of seven fish bioenergetics models (BEMs) were used to investigate possible associations between BEM prediction error in relative growth rate (RGRerror) and levels of model input variables: mean daily food-consumption rate and fish body weight. Correlation between RGRerror and fish body weight was found in three BEMs applied under submaintenance feeding conditions. A strong correlation between RGRerror and mean daily consumption level was observed in all models over full consumption ranges; consumption level explained 70%–96% of variation in RGRerror. All BEMs underestimated (by 2- to 5-fold) growth at lower consumption levels and overestimated (by 2- to …

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Comparison Of Bluegill Consumption Rates By Largemouth Bass And Sunshine Bass In Structured And Nonstructured Artificial Environments, Christopher W. Hickey, Christopher C. Kohler Nov 2004

Comparison Of Bluegill Consumption Rates By Largemouth Bass And Sunshine Bass In Structured And Nonstructured Artificial Environments, Christopher W. Hickey, Christopher C. Kohler

Publications

We compared consumption rates of bluegills Lepomis macrochirus by largemouth bass Micropterus salmoides and sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) in structured (about 50% coverage with artificial vegetation) and nonstructured 2,000-L fiberglass tanks. In the presence of structure, instantaneous bluegill mortality from consumption by largemouth bass was significantly higher than that caused by sunshine bass but was similar when structure was absent. Instantaneous bluegill mortality from consumption by wild largemouth bass was significantly higher than by pellet-trained largemouth bass in both structured and nonstructured environments. When pellet-trained sunshine bass served as the predator, …

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The Economic Situation, 2004 October, Bruce Yandle Oct 2004

The Economic Situation, 2004 October, Bruce Yandle

Publications

Quarterly report on the economic situation of the United States and South Carolina.

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Funding And Managing America's Transportation Systems, 2004 October, Clinton H. Whitehurst Jr. Oct 2004

Funding And Managing America's Transportation Systems, 2004 October, Clinton H. Whitehurst Jr.

Publications

No abstract provided.

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The Correlation Of Lithium And Beryllium In F And G Cluster Dwarf Stars, Ann Merchant Boesgaard, Eric Armengaud, Constantine P. Deliyannis, Alex Stephens, Jeremy R. King Oct 2004

The Correlation Of Lithium And Beryllium In F And G Cluster Dwarf Stars, Ann Merchant Boesgaard, Eric Armengaud, Constantine P. Deliyannis, Alex Stephens, Jeremy R. King

Publications

Although Li has been extensively observed in main-sequence field and cluster stars, there are relatively fewer observations of Be. We have obtained Keck HIRES spectra of 36 late F and early G dwarfs in order to study the Li-Be correlation we found previously in the temperature regime of 5900–6650 K. The sample size for this temperature range with detectable and (usually) depleted Li and Be is now 88, including Li and Be abundances in both cluster and field stars. Therefore we can now investigate the influence of other parameters such as age, temperature, and metallicity on the correlation. The Be …

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Energetics, Predation, And Ration Affect Size-Dependent Growth And Mortality Of Fish During Winter, James E. Garvey, Kenneth G. Ostrand, David H. Wahl Oct 2004

Energetics, Predation, And Ration Affect Size-Dependent Growth And Mortality Of Fish During Winter, James E. Garvey, Kenneth G. Ostrand, David H. Wahl

Publications

Winter temperatures may reduce energy costs for ectotherms. However, variable mid-temperate and low-latitude winters may interact with scaling of size, metabolism, and energy reserves to cause energy deficits and require trade-offs between foraging and predation. A dynamic optimization model explored how ration, fall fat, and both non- and size-selective predation influenced foraging (i.e., fast or forage) and energy allocation (i.e., length or fat) decisions that maximize winter survival of age-0 largemouth bass (Micropterus salmoides). During a mid-latitude (38° N) winter, a pond experiment in which age-0 fish occurred with or without adult conspecific predators tested a subset of …

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Real-Time Spectroscopic Ellipsometry Study Of Ultrathin Diffusion Barriers For Integrated Circuits, S M. Aouadi, P K. Shreeman, M Williams Oct 2004

Real-Time Spectroscopic Ellipsometry Study Of Ultrathin Diffusion Barriers For Integrated Circuits, S M. Aouadi, P K. Shreeman, M Williams

Publications

The objective of this work is to monitor the growth process and the thermal stability of ultrathin tantalum nitride barrier nanostructures against copper diffusion in integrated circuits using real-time spectroscopic ellipsometry (RTSE). Single layers of copper and bilayer films of copper and tantalum nitride were produced on Si(111) substrates using unbalanced magnetron sputtering. The RTSE data was simulated using the Bruggeman effective medium approximation and a combined Drude-Lorentz model to obtain information about the growth process, film architecture, interface quality, and the conduction electron transport properties for these structures. The results deduced from the RTSE were verified by characterizing the …

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Photometric Identification Of Cool White Dwarfs, M. Kilic, D. E. Winget, Ted Von Hippel, C. F. Claver Oct 2004

Photometric Identification Of Cool White Dwarfs, M. Kilic, D. E. Winget, Ted Von Hippel, C. F. Claver

Publications

We investigate the use of a narrowband DDO51 filter for photometric identification of cool white dwarfs. We report photometric observations of 30 known cool white dwarfs with temperatures ranging from 10,000 K down to very cool temperatures (3500 K). Follow-up spectroscopic observations of a sample of objects selected using this filter and our photometric observations show that DDO51 filter photometry can help select cool white dwarf candidates for follow-up multiobject spectroscopy by rejecting 65% of main-sequence stars with the same broadband colors as the cool white dwarfs. This technique is not selective enough to efficiently feed single-object spectrographs. We present …

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Asymptotic Accuracy Of Geoacoustic Inversions, Michele Zanolin, Ian Ingram, Aaron Thode, Nicholas C. Makris Oct 2004

Asymptotic Accuracy Of Geoacoustic Inversions, Michele Zanolin, Ian Ingram, Aaron Thode, Nicholas C. Makris

Publications

Criteria necessary to accurately estimate a set of unknown geoacoustic parameters from remote acoustic measurements are developed in order to aid the design of geoacoustic experiments. The approach is to have estimation error fall within a specified design threshold by adjusting controllable quantities such as experimental sample size or signal-to-noise ratio (SNR). This is done by computing conditions on sample size and SNR necessary for any estimate to have a variance that (1) asymptotically attains the Cramer–Rao lower bound (CRLB) and (2) has a CRLB that falls within the specified design error threshold. Applications to narrow band deterministic signals received …

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Redefining The Empirical Zz Ceti Instability Strip, Anjum S. Mukadam, Ted Von Hippel, Et Al. Sep 2004

Redefining The Empirical Zz Ceti Instability Strip, Anjum S. Mukadam, Ted Von Hippel, Et Al.

Publications

We use the new ZZ Ceti stars (hydrogen-atmosphere white dwarf variables; DAVs) discovered within the Sloan Digital Sky Survey (Mukadam et al. 2004) to redefine the empirical ZZ Ceti instability strip. This is the first time since the discovery of white dwarf variables in 1968 that we have a homogeneous set of spectra acquired using the same instrument on the same telescope, and with consistent data reductions, for a statistically significant sample of ZZ Ceti stars. The homogeneity of the spectra reduces the scatter in the spectroscopic temperatures, and we find a narrow instability strip of width ~950 K, from …

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Involvement Of Raft-Like Plasma Membrane Domains Of Entamoeba Histolytica In Pinocytosis And Adhesion, Richard C. Laughlin, Glen C. Mcgugan, Rhonda R. Powell, Brenda H. Welter, Lesly A. Temesvari Sep 2004

Involvement Of Raft-Like Plasma Membrane Domains Of Entamoeba Histolytica In Pinocytosis And Adhesion, Richard C. Laughlin, Glen C. Mcgugan, Rhonda R. Powell, Brenda H. Welter, Lesly A. Temesvari

Publications

Lipid rafts are highly ordered, cholesterol-rich, and detergent-resistant microdomains found in the plasma membrane of many eukaryotic cells. These domains play important roles in endocytosis, secretion, and adhesion in a variety of cell types. The parasitic protozoan Entamoeba histolytica, the causative agent of amoebic dysentery, was determined to have raft-like plasma membrane domains by use of fluorescent lipid analogs that specifically partition into raft and nonraft regions of the membrane. Disruption of raft-like membrane domains in Entamoeba with the cholesterol-binding agents filipin and methyl-β-cyclodextrin resulted in the inhibition of several important virulence functions, fluid-phase pinocytosis, and adhesion to host …

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Recognizing And Overcoming Difficult Site Conditions For Afforestation Of Bottomland Hardwoods, William Conner, J A. Stanturf, E S. Gardiner, C J. Schweitzer, A W. Ezell Sep 2004

Recognizing And Overcoming Difficult Site Conditions For Afforestation Of Bottomland Hardwoods, William Conner, J A. Stanturf, E S. Gardiner, C J. Schweitzer, A W. Ezell

Publications

In the last decade, about 370,000 acres (150,000 ha) of economically marginal
farmland in the Lower Mississippi Alluvial Valley (LMAV) have been restored to
bottomland hardwood forests (Stanturf and others 1998, King and Keeland 1999,
Schoenholtz and others 2001). Planting of this considerable acreage is due to several federal programs, such as the Wetlands Reserve Program (WRP), that assist landowners by financing afforestation (Figure 1). Unfortunately, these operational plantings have not performed as well as smaller plantings or research plots (Stanturf and others 2001a). For example, a recent survey of WRP plantings in westcentral Mississippi revealed that more than 90 …

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Paternity And Relatedness Of American Black Bears Recolonizing A Desert Montane Island, Dave P. Onorato, Eric C. Hellgren, Ronald A. Van Den Bussche, J. Raymond Skiles, Jr. Aug 2004

Paternity And Relatedness Of American Black Bears Recolonizing A Desert Montane Island, Dave P. Onorato, Eric C. Hellgren, Ronald A. Van Den Bussche, J. Raymond Skiles, Jr.

Publications

American black bears (Ursus americanus (Pallas, 1780)) are characterized by female philopatry and malebiased dispersal, with predictable consequences for genetic structure of populations. We studied a recolonizing population of black bears on a desert montane island to test genetic-based predictions of bear social behavior. We assessed genetic paternity and relatedness among bears within Big Bend National Park, Texas, from 1998 to 2001 via maternally and biparentally inherited markers and field observations. Data from seven microsatellite loci permitted us to assign paternity for 7 of 12 cubs, and multiple paternity was revealed in one litter. Levels of relatedness in the …

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Size Induced Variations In Structural And Magnetic Properties Of Double Exchange La0.8sr0.2mno3−Δ Nano-Ferromagnet, Sujoy Roy, Igor Dubenko, Dossah D. Edorh, Naushad Ali Jul 2004

Size Induced Variations In Structural And Magnetic Properties Of Double Exchange La0.8sr0.2mno3−Δ Nano-Ferromagnet, Sujoy Roy, Igor Dubenko, Dossah D. Edorh, Naushad Ali

Publications

A detailed study on the influence of particle size varied from 8 nm to 53 nm on the structural and magnetic properties of La0.8Sr0.2MnO3−δ has been done. The unit cell volume increases and the microstrain in the compound shows peak formation as the particle size decreases. Nano particles of La0.8Sr0.2MnO3−δ exhibit superparamagnetism whose blocking temperature has a nonlinear and logarithmic decreasing tendency as function of particle size and applied magnetic field, respectively. Evidence of formation of a magnetically dead layer at the surface has been found and the …

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Proper Motion Objects In The Hubble Deep Field, M. Kilic, Ted Von Hippel, Et Al. Jul 2004

Proper Motion Objects In The Hubble Deep Field, M. Kilic, Ted Von Hippel, Et Al.

Publications

Using the deepest and finest resolution images of the universe acquired with the Hubble Space Telescope and a similar image taken 7 yr later for the Great Observatories Origins Deep Survey, we have derived proper motions for the point sources in the Hubble Deep Field–North. Two faint blue objects, HDF 2234 and HDF 3072, are found to display significant proper motion, 10:0 ± 2:5 and 15:5 ± 3:8 mas yr¯1. Photometric distances and tangential velocities for these stars are consistent with disk white dwarfs located at ~500 pc. The faint blue objects analyzed by Ibata et al. and Mendez & …

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The Coming North American Rail Mergers, 2004 July, Clinton H. Whitehurst Jr., Richard L. Clarke Jul 2004

The Coming North American Rail Mergers, 2004 July, Clinton H. Whitehurst Jr., Richard L. Clarke

Publications

No abstract provided.

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The Economic Situation, 2004 July, Bruce Yandle Jul 2004

The Economic Situation, 2004 July, Bruce Yandle

Publications

Quarterly report on the economic situation of the United States and South Carolina.

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The Near-Infared Survey Of The N49 Region Around The Soft Gamma Repeater Sgr 0526-66, S. Klose, A. A. Henden, U. Geppert, J. Greiner, H. H. Guetter, Dieter H. Hartmann, C. Kouveliotou, C. B. Luginbuhl, B. Stecklum, F. J. Vrba Jul 2004

The Near-Infared Survey Of The N49 Region Around The Soft Gamma Repeater Sgr 0526-66, S. Klose, A. A. Henden, U. Geppert, J. Greiner, H. H. Guetter, Dieter H. Hartmann, C. Kouveliotou, C. B. Luginbuhl, B. Stecklum, F. J. Vrba

Publications

We report the results of a deep near-infrared survey with the Very Large Telescope/Infrared Spectrometer and Array Camera of the environment of the supernova remnant N49 in the Large Magellanic Cloud, which contains the soft gamma repeater SGR 0526-66. Two of the four confirmed SGRs are potentially associated with compact stellar clusters. We thus searched for a similar association of SGR 0526-66 and imaged a young stellar cluster at a projected distance of ∼30 pc from the SGR. This constitutes the third cluster–SGR link and lends support to scenarios in which SGR progenitors originate in young dusty clusters. If confirmed, …

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The Upper Limit For Ch4 In The Protostellar Disk Toward Hl Tauri, E L. Gibb, T Rettig, Sean D. Brittain, R Haywood, Theodore Simon, C Kulesa Jul 2004

The Upper Limit For Ch4 In The Protostellar Disk Toward Hl Tauri, E L. Gibb, T Rettig, Sean D. Brittain, R Haywood, Theodore Simon, C Kulesa

Publications

We used high-resolution infrared spectra of the heavily embedded T Tauri star HL Tau to search for evidence of absorption due to the R0, R1, and R2 gas-phase CH4 ν3 lines near 3.3 μm. From this, we report a 3 σ upper limit of 1.3 × 1015 cm-2 for the CH4 gas column density toward HL Tau. Our results are compared to those found for CO gas toward this source and to the recent model for chemistry in the inner (10 AU) disks around T Tauri stars by Markwick et al. We find that the upper limit of methane ice+gas …

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The Cold War's "Undigested Apple Dumpling': Imaging Moby-Dick In 1956 And 2001, Walter C. Metz Jul 2004

The Cold War's "Undigested Apple Dumpling': Imaging Moby-Dick In 1956 And 2001, Walter C. Metz

Publications

A survey of the intertextual linkages between Herman Melville's Moby-Dick (1851) and the cinema, with special attention to the Cold War period.

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A Systematic Analysis Of Supernova Light In Gamma-Ray Burst Afterglows, A. Zeh, S. Klose, Dieter H. Hartmann Jun 2004

A Systematic Analysis Of Supernova Light In Gamma-Ray Burst Afterglows, A. Zeh, S. Klose, Dieter H. Hartmann

Publications

We systematically reanalyzed all gamma-ray burst (GRB) afterglow data published through the end of 2002 in an attempt to detect the predicted supernova light component and to gain statistical insight into its phe-nomenological properties. We fit the observed photometric light curves as the sum of an afterglow, an underlying host galaxy, and a supernova component. The latter is modeled using published multicolor light curves of SN 1998bw as a template. The total sample of afterglows with established redshifts contains 21 bursts (GRB 970228–GRB 021211). For nine of these GRBs a weak supernova excess (scaled to SN 1998bw) was found, which …

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An Integrated Analysis Of Pre-Hispanic Mortuary Practices: A Middle Sicán Case Study, Izumi Shimada, Ken-Ichi Shinoda, Julie Farnum, Robert Corruccini, Hirokatsu Watanabe Jun 2004

An Integrated Analysis Of Pre-Hispanic Mortuary Practices: A Middle Sicán Case Study, Izumi Shimada, Ken-Ichi Shinoda, Julie Farnum, Robert Corruccini, Hirokatsu Watanabe

Publications

Recent debate has raised serious questions about the viability of the social and ideological reconstruction of prehistoric culture on the basis of mortuary analysis. In recent years bioarchaeology has gained considerable prominence, underscoring the fact that death, burials, and associated mortuary practices are multifaceted phenomena shaped by biological, social, ideological, and taphonomic factors. Few studies attempting social reconstruction through mortuary analysis, including those of a bioarchaeological character, have adequately addressed this multidimensionality. This study shows that social, ideological, and bioarchaeological reconstruction can be productively pursued through tight integration of a multitude of approaches and perspectives set within a long‐term regional …

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Thirty-Five New Pulsating Da White Dwarf Stars, Anjum S. Mukadam, Ted Von Hippel, Et Al. Jun 2004

Thirty-Five New Pulsating Da White Dwarf Stars, Anjum S. Mukadam, Ted Von Hippel, Et Al.

Publications

We present 35 new pulsating DA (hydrogen atmosphere) white dwarf stars discovered from the Sloan Digital Sky Survey (SDSS) and the Hamburg Quasar Survey (HQS). We have acquired high-speed time series photometry of preselected DA white dwarfs with a prime focus CCD photometer on the 2.1 m telescope at McDonald Observatory over 15 months. We selected these stars on the basis of prior photometric and spectroscopic observations by the SDSS and HQS. For the homogeneous SDSS sample, we achieve a success rate of 80% for finding new variables at a detection threshold of 0.1%-0.3%. With 35 newly discovered DA variable …

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