bluuebunny/crossref_metadata_2025 huggingface dataset:
Paired AMS 14C Dates on Planktic Foraminifera from a Gulf of Mexico Sediment Core: An Assessment of Stratigraphic Continuity
Authors: Flower B P , Hastings D W , Randle N J
Published: July 2016

A series of recent papers has called for multiple radiocarbon dates on planktic foraminifera to assess stratigraphic continuity in deep-sea sediment cores. This recommendation comes from observations of anomalous 14C dates in planktic foraminifera from the same stratigraphic level. Potential reasons include bioturbation, downslope transport, secondary calcification, carbonate dissolution, and differential preservation. In this study, paired 14C dates on dissolution-susceptible Globigerinoides ruber and dissolution-resistant Neogloboquadrina dutertrei are used to evaluate a Gulf of Mexico sediment core. Fourteen of 15 pairs (between 8815 and 12,995 uncorrected 14C yr BP) yield concordant uncorrected 14C ages (mean difference −2 ± 75 yr), attesting to continuous deposition at high accumulation rates (>35 cm/kyr). For 1 pair, N. dutertrei is nearly 1000 yr younger, which is difficult to explain by any combination of dissolution and bioturbation or downslope transport, given the excellent carbonate preservation and persistent laminations. The concordant ages underscore the utility of paired 14C dates in planktic foraminifera as a means of assessing stratigraphic continuity in deep-sea sediment sequences.
Possible Factors Causing Older Radiocarbon Age for Bulk Organic Matter in Sediment from Daihai Lake, North China
Authors: Wu Yanhong , Wang Sumin , Zhou Liping
Published: July 2016

Many factors may influence the radiocarbon age results of lacustrine sediments, among which the hardwater effect is particularly important. Daihai Lake is a closed lake located in the semi-arid region of Inner Mongolia, China. High concentrations of HCO3- and CO32- and high pH values in the lake water imply that there is a hardwater effect when using bulk lacustrine sediment samples for 14C dating. To correct the apparent 14C age, we present a pilot study based on a series of 14C ages of lake surface sediment, lake water, submerged aquatic plant (Myriophyllum), fish bone (Cyprinus carpio), and surface soil samples from and around Daihai Lake. Assuming that the relationship between the 14C/12C ratio of DIC and of atmospheric CO2 was constant (at 0.816), the hardwater effect ages calculated for the past 8000 yr would have varied from 949 to 1788 yr. Together with the reservoir effect and soil organic matter input, the hardwater effect is a major factor causing changes in apparent age when using bulk organic matter for 14C dating.
Rice University Radiocarbon Dates I
Authors: Beck Barry F.
Published: July 2016

The radiocarbon dating laboratory at Rice University first became operative in the fall of 1970. A workable technique has been developed although operations are still in a state of flux. The benzene liquid scintillation counting method is used, the benzene being prepared as outlined by Noakes, Kim, and Akers (1967) with the following modifications. The CO2 is further purified prior to storage and measuring by passing it through 3 gas bubblers containing potassium permanganate solution, silver nitrate solution, and a sulfuric acid-sodium dichromate solution (S. Valastro, pers. commun., 1970). Since no C12 C13 analyses are available at present, to insure a complete reaction, both the CO2 generation and the C2H2 generation are continued for ½ hr after all visible signs of reaction have disappeared.
The Radiocarbon Content of Individual Lignin-Derived Phenols: Technique and Initial Results
Authors: McNichol A P , Ertel J R , Eglinton T I
Published: July 2016

We present a method for the isolation of phenolic compounds derived from lignin for radiocarbon analysis. These phenols are generated by chemical oxidation of polymeric materials and derivatized for separation and recovery by preparative capillary gas chromatography (PCGC). This technique yields tens of micrograms of pure, stable compounds that can be converted to graphite and analyzed by accelerator mass spectrometry (AMS). Analysis of model flavor compounds and dated woods indicates that, in most cases, the radiocarbon (14C) contents of the individual compounds, corrected for the contribution of the derivative, agree with that of the bulk material to within 20%.
Mammoths, Measured Time, and Mistaken Identities
Authors: Haynes Gary
Published: July 2016

Mammoth and mastodont sites containing broken or cut bones are not rare in the New World, but their meanings are ambiguous. Studies of recent African elephant bone sites indicate that certain processes in nature create bone modifications that are identical to the end-effects of human actions such as butchering. In designing a rational and efficient approach to the radiometric dating of fossil proboscidean sites, caution and skepticism should enter into interpretations of modified materials.
AMS Dating Mammoth Bones: Comparison with Conventional Dating
Authors: Vasil'chuk Yurij K , Vasil'chuk Alla C , Long Austin , Jull A J T , Donahue D J
Published: July 2016

Fossilized Siberian mammoth remains are important indicators of environmental change in the Late Pleistocene. The NSF-Arizona AMS Laboratory radiocarbon results on amino acid separations compare well with mammoth bone collagen from the same specimens treated by HCl and dated by beta counting (the Russian Academy Geological Institute Radiocarbon Laboratory). Neither laboratory was aware of the other's dates for these comparisons. The results coincide very closely (a difference of 50–800 yr), and demonstrate that AMS dating provides a very good perspective for applications of past mammoth population studies.
University of Georgia Radiocarbon Dates II
Authors: Brandau Betty Lee , Noakes John E.
Published: July 2016

The following list of dates is compiled from samples prepared since publication of our last date list (R., 1971, v. 13, p. 468-474). The counting equipment and operating procedures are the same. Ages are quoted with a lσ counting error which includes statistical variation of the sample count as well as for the background and standard, using a.d. 1950 as the reference year and 0.95% NBS oxalic acid for C14 dating as the standard. The half-life value used is 5570 years.
Ucr Radiocarbon Dates II
Authors: Taylor R E
Published: July 2016

UCR I (R, 1974, v 16, p 395–401) previously reported measurements carried out jointly by the UCR and UCLA radiocarbon laboratories between November 1972 and September 1973 and interlaboratory check samples used to calibrate the UCR 1.7L counter. This list reports the measurements of the UCR laboratory from September 1973 to August 1974.
Radiocarbon and 11-Year Variations of Cosmic Rays
Authors: Burchuladze A. A. , Pagava S. V. , Togonidze G. I. , Avtandilashvili M. V.
Published: July 2016

B. P. Konstantinov and G. E. Kocharov (1965, 1967) addressed the complex problem of astrophysical phenomena and radiocarbon. Currently available data show that the determination of cosmogenic 14C in accurately dated samples of terrestrial and atmospheric origin is one of the most reliable and promising methods for studying cosmic-ray variations in the past. 14C dating samples of terrestrial origin has helped solve the problem of long-term (100 yr or more) 14C variations and, accordingly, of cosmic-ray variations in the past. Short-term (ca. 11 yr or less) variations are still under investigation (Alexeyev et al. 1971; Damon, Long and Wallick 1973).
Reconstruction of Caspian Sea-Level Fluctuations: Radiocarbon Dating Coastal and Bottom Deposits
Authors: Karpytchev Yu. A.
Published: July 2016

Owing to the large basin area of the Caspian Sea, fluctuations in its level reflect climatic changes in the northern hemisphere. To reconstruct these fluctuations, I collected mollusk shells, plant debris, carbonates and organic matter samples for 14C dating from deposits of ancient salt marshes, depressions and bars formed during significant sea-level decline. I studied the impact of eolian sedimentation via parallel dating of carbonates and other materials. The data demonstrate that sea level rises during periods of cooling and falls during warming periods; this is true for both long-term (2–2.5 ka) and short-term climatic changes.
Evaluation of a Prototype Low-Level Liquid Scintillation Multisample Counter
Authors: Einarsson Sigurđur A.
Published: July 2016

A new, improved photomultiplier has been incorporated and a more efficient active guard installed in a single photomultiplier liquid scintillation counter. A special quartz vial was designed to improve the photoelectron cathode index (photoelectrons/keV), and thus, to reduce background. Four photomultipliers were installed so that four samples can be counted simultaneously. The measurements presented here cover background spectra and counting efficiency obtained under various conditions in the laboratory. These measurements and derived parameters, such as the figure of merit (E2/B) and the factor of merit (S/√B), are used to evaluate the system performance. Also presented are the results of measurements on the cathode index and further background spectra, obtained at an underground site.
High-Performance 14C Gas-Proportional Counting System Applying Pulse-Shape Discrimination
Authors: Äikää Osmo , Mäntynen Pertti , Kankainen Tuovi
Published: July 2016

The new 14C dating system of the Geological Survey of Finland consists of three CO2 proportional counters of conventional size, a liquid scintillation anticoincidence guard, and a passive shield of about 90-year-old iron. The counting room is an air-conditioned Faraday cage constructed of concrete with aggregate of crystalline Precambrian limestone. We apply pulse-shape discrimination that greatly improves the precision of our 14C analyses - the reduction of background is over 70%, while the modern count rate is reduced only by 15 to 20%. The purity of the counting gas is monitored by recording the cosmic muon pulse-height spectrum. At present, the dating limit for a two-day measurement is 57 ka. We summarize here the most significant results and aspects of pulse-shape discrimination
Prime Lab: A Dedicated AMS Facility at Purdue University
Authors: Elmore David , Rickey F. A. , Simms P. C. , Lipschutz M. E. , Mueller K. A. , Miller T. E.
Published: July 2016

A new facility for accelerator mass spectrometry has been established at Purdue University. First results have been obtained for 10Be and 36C1, and several internal research projects have been initiated. Plans are to become a national AMS facility to serve the Earth and planetary science communities for the full range of cosmogenic radionuclides.
The New National Ocean Sciences Accelerator Mass Spectrometer Facility at Woods Hole Oceanographic Institution: Progress and First Results
Authors: Von Reden K. F. , Jones G. A. , Schneider R. J. , McNichol A. P. , Cohen G. J. , Purser K. H.
Published: July 2016

Start-up performance and first results of the new Woods Hole Accelerator Mass Spectrometer are discussed. Special attention is given to the hemispherical ionizer sputter source and the triple-isotope injector design.
The New Groningen 14C Data Base
Authors: Van Der Plicht Johannes
Published: July 2016

The Groningen Radiocarbon Data base has been operating on an Apple IIe PC until recently. Both software and hardware of this data base made exchange with other systems very difficult. Therefore, the data base has been transferred to an IBM AT compatible computer. A new program has been written in Turbo-Pascal, using the Turbo-Pascal Database Toolbox. The program features versatile search routines. The output can be directed to various date-list formats, such as the International Radiocarbon Data Base (IRDB). The program is written in such a way that new date lists can be added with minor adjustments to the source code.
Experimental Determination of the 14C Initial Activity of Calcareous Deposits
Authors: Bronić Ines Krajcar , Horvatinčić Nada , Srdoč Dušan , Obelić Bogomil
Published: July 2016

We have reconstructed the initial activity of calcareous sediments by 1) measuring the 14C activity of recent pre-bomb-test calcareous deposits, 2) calculating the ratio of the 14C activity of the calcareous sediment to that of the adjacent coeval wood, and 3) extrapolating 14C activity of the deep lacustrine sediment layers to the surface, assuming a constant sedimentation rate. We show here that the uppermost sediment is affected by the global increase of atmospheric 14C activity due to thermonuclear bomb tests in the early 1960s. 14C activity of submerged aquatic plants showed values similar to 14C activity of DIC. Thus, organic residue of the sediment cannot be used for reliable 14C dating because of the unknown fraction of aquatic plant detritus. The initial activity, A0, obtained in a case study of the geochronology of carbonates in the Plitvice Lakes area, ranged from 70.5 to 72.2 pMC for Lake Prošće sediment, and from 75.9 to 76.7 pMC for Lake Kozjak sediment. These values also agree with calculated values based on the downstream increase of 14C activity of DIC in freshwater open to the atmosphere.
Comparing Continental Carbonates with Other Materials in Dating a Paleolake
Authors: Garcia J. F. , Mestres J. S. , Rauret Gemma
Published: July 2016

We have studied the application of carbonates and organic matter to the radiocarbon dating of a paleolake. The results show a systematic apparent age shift of these materials with respect to contemporary wood. The apparent age of carbonates is evidently due to the hard-water effect, whereas the apparent age of organic matter, systematically younger than carbonates, is attributed to aquatic plants, which metabolize dissolved CO2. Terrestrial plants that deposit organic matter also cause apparent age discrepancies between carbonates and organic matter.
Radiocarbon Dating of Travertines Precipitated from Freshwater
Authors: Mas-Pla Josep , Trilla Josep , Valls Maria Lluisa
Published: July 2016

We have studied the isotopic composition of recently precipitated travertines to determine the initial 14C activity of ancient travertine deposits. We found that the 14C activity of recent travertines of northeastern Spain was a function of the distance from the spring, resulting in variations in the initial 14C activity of the ancient travertine formations. We calculated the ancient travertine radiocarbon ages by using the ratio between the 14C activity of recent travertines and that of present atmospheric CO2 as the initial 14C activity.
Anthropogenic Radiocarbon in the Eastern Irish Sea and Scottish Coastal Waters
Authors: Begg F. H. , Cook G. T. , Baxter M. S. , Scott E. M. , McCartney Martin
Published: July 2016

14C is produced as an activation product in nuclear reactors, and may be discharged to both the atmosphere and the marine environment during nuclear fuel reprocessing. In the UK, 14C is discharged, under license, into the Eastern Irish Sea by the British Nuclear Fuels plc (BNFL) reprocessing plant at Sellafield, Cumbria, northwest England, and is then transported into Scottish coastal waters. We analyzed intertidal biota samples to determine the effect of these discharges. The specific activities of 14C found in these samples indicate that the uptake and bioaccumulation of 14C is dependent on the type of organism and its feeding behavior. Measured 14C concentrations in mussels (Mytilus edulis) were higher than those in winkles (Littorina littorea), which were greater than those found in seaweed (Fucus spp.); maximum observed activities were ca. 7, 5 and 3.5 times the accepted current ambient level of 260 Bq kg−1 C, respectively. Annual Nori (Porphyra umbilicalis) samples were analyzed for their 137Cs, 241Am and 14C contents; both the 137Cs and 241Am results correlated well with published Sellafield discharge data (r = 0.877 and 0.918, respectively), whereas there was no significant correlation between measured 14C activities and the discharge record, indicating increased complexity in the chemical and biological behavior of 14C or some discrepancy in the estimated discharge records.
14C Profiles in the Norwegian and Greenland Seas by Conventional and AMS Measurements
Authors: Nydal Reidar , Gislefoss Jorunn , Skjelvan Ingunn , Skogseth Fred , Jull A. J. T. , Donahue D. J.
Published: July 2016

CO2 in the atmosphere is an important climate gas because of its absorption of infrared radiation. More knowledge about CO2 uptake in the ocean is of critical significance in predicting future climate development. For a period of approximately 30 years, radioactive carbon from nuclear tests has been a very useful tracer in CO2 exchange studies. Up to now, the measurements have been based mainly on the conventional counting technique with large CO2 samples (ca. 5 liters). Accelerator mass spectrometry (AMS) with small CO2 samples (1–2 ml) has made sampling much easier, and has especially stimulated the use of 14C as a tracer in the ocean.

At higher latitudes, the ocean acts as a sink for CO2. In addition to Δ14C measurements, we are concerned here with dissolved inorganic carbon (DIC) and δ13C in the Norwegian and Greenland Seas. During cruises in 1989 and 1990, we obtained several Δ14C profiles, and also repeated a few GEOSECS profiles taken in 1972. The shape of these profiles changes with time, and provides information about the mixing rate and the age of the deep water. From changes in the profiles, it appears that the deep water in the Greenland Sea has obtained about 25% of the 14C concentration in the ocean surface over a period of 25 years. The Norwegian Sea deepwater is estimated to be 50–100 years older than that of the Greenland Sea.
Measurement of 14C Concentrations of Stratospheric CO2 by Accelerator Mass Spectrometry
Authors: Nakamura Toshio , Nakazawa Takakiyo , Nakai Nobuyuki , Kitagawa Hiroyuki , Honda Hideyuki , Itoh Tomizo , Machida Toshinobu , Matsumoto Eiji
Published: July 2016

In order to measure the concentrations of anthropogenically influenced gases in the stratosphere, we have collected air samples from the lower stratosphere since 1985, by a balloon-borne cryogenic sampling method, developed at the Institute of Space and Astronautical Science (ISAS). Air samples of ≃16 liters at STP were collected in the stratosphere at altitudes from 18.6 to 30.4 km, over the northeastern part of Japan (39.5°N, 139–142°E), on 1 September 1989. We conducted 14C analyses to study the vertical and horizontal air-mass movement in the stratosphere, and to investigate the air transport mechanism between troposphere and stratosphere. Carbon dioxide (containing a few mg carbon) was separated cryogenically from the air samples, and the 14C concentration of the CO2 was measured by a Tandetron accelerator mass spectrometer, using Fe-graphite targets prepared by reducing CO2 on Fe-powder with hydrogen in a Vycor tube at 650°. The 14C concentrations, expressed as Δ14C, of CO2 were 267–309‰ at altitudes of 21–30 km, and 134‰ at 19–20 km. The Δ14C values at 21–30 km were higher than those of the current tropospheric CO2, of around 80–200‰. The observed 14C concentrations, higher in the stratosphere than the troposphere, seem to be explained by large bomb-produced 14C inventories and/or high 14C production by cosmic rays, as well as weak vertical mixing of air masses in the stratosphere.
Bomb-Produced 14C in Tree Rings
Authors: Kaimei Dai , Youneng Qian , Fan C. Y.
Published: July 2016

The 14C content in 1961–1967 and 1970–1983 tree rings of a spruce grown in Dailing, China (47°N, 129°E) was measured by liquid scintillation. As a result of USSR bomb tests at Novaya Zemlya (72°N, 53°E), Δ14C values rose dramatically from 250‰ in 1961 to a maximum 909‰ in 1964, and then gradually decreased to 238‰ in 1983. We compared Δ14C values in the rings of an oak tree grown at 43°N, 74°W and that of a pine grown at 49°N, 9°E, and atmospheric Δ14C values in both northern and southern hemispheres. We observe that: 1) annual tree rings grown in the same latitude zone have the same Δ14C values, reflecting rapid longitudinal mixing of the atmosphere; 2) atmospheric 14C concentrations reached a global equilibrium distribution at the end of 1968, and tree ring 14C content reflects atmospheric 14C concentration; 3) 1976–1982 rings of the Dailing spruce show excessive 14C, likely due to the effect of 1976 and 1980 Chinese bomb tests; 4) Δ14C decreases exponentially, halving every 17 yr.
Radiocarbon Results for the British Beakers
Authors: Ambers Janet , Bowman Sheridan , Gibson Alex , Kinnes Ian
Published: July 2016

The beginning of the Bronze Age in the British Isles has traditionally been marked by the appearance, in the archaeological record, of Beaker assemblages, mainly characterized by the Beaker pottery form itself. Ceramic typologies based on this style, which is undoubtedly continental in origin, have been used both for relative dating and as evidence of the social and economic developments of the period. Systematic radiocarbon dating has been attempted for the continental European Beaker material (Lanting, Mook & van der Waals 1973), but no such program has been carried out on British material. An examination of the existing radiocarbon results for the British Beakers showed many to be flawed in some way, particularly in the use of materials, such as mature wood, where there is no a priori reason for assuming a direct relationship between sample death and context. An attempt has been made at the British Museum to test the validity of archaeologically derived chronologies for the Beaker pottery of the British Isles. This involved analysis of a group of carefully selected human bone samples from Beaker burials, where there is a known direct association between ceramic usage and the cessation of carbon exchange. Twenty such samples have been identified and measured. The results presented here, combined with other previously produced determinations, show no obvious relationship between pottery style and calendar date of deposition.
Louvain Natural Radiocarbon Measurements VII
Authors: Gilot E.
Published: July 2016

The following list comprises selected measurements made during 1967–68. The method is essentially the same as previously described. A 0.6 L proportional gas-counter at 3 atm CH4pressure is used. Ages are given relative to A.D. 1950 and half-life of 5570 yr has been assumed. The quoted error is the experimental standard deviation and includes the uncertainty on the unknown sample, the modern standard and the background.
Monaco Radiocarbon Measurements III
Authors: Thommeret J. , Thommeret Y.
Published: July 2016

The following list of dates contains most of the measurements obtained since our last list. Procedures of measurements and calculation are as previously described in Radiocarbon, 1964, v. 6, p. 194–196; 1966, v. 8, p. 286–291. A new 1.1 L counter, all metal and quartz, built in the laboratory has been in use since 1967.
University of Wisconsin Radiocarbon Dates VI
Authors: Bender Margaret M. , Bryson Reid A. , Baerreis David A.
Published: July 2016

The radiocarbon dates obtained since December 1967 are included in this report. The procedures followed have been described previously (Radiocarbon, 1966, v. 8, p. 522–533).
Radiocarbon Dating of Buried Holocene Soils in Siberia
Authors: Orlova Lyubov A , Zykina Valentina S
Published: July 2016

We have constructed a detailed chronological description of soil formation and its environments with data obtained on radiocarbon ages, palynology, and pedology of the Holocene buried soils in the forest steppe of western and central Siberia. We studied a number of Holocene sections, which were located in different geomorphic situations. Radiocarbon dating of materials from several soil horizons, including soil organic matter (SOM), wood, peat, charcoal, and carbonates, revealed three climatic periods and five stages of soil formation in the second part of the Holocene. 14C ages of approximately 6355 BP, 6020 BP, and 5930 BP showed that the longest and most active stage is associated with the Holocene Climatic Optimum, when dark-grey soils were formed in the forest environment. The conditions of birch forest steppe favored formation of chernozem and associated meadow-chernozem and meadow soils. Subboreal time includes two stages of soil formation corresponding to lake regressions, which were less intense than those of the Holocene Optimum. The soils of that time are chernozem, grassland-chernozem, and saline types, interbedded with thin peat layers 14C dated to around 4555 B P, 4240 BP and 3480 BP, and 3170 B P. Subatlantic time includes two poorly developed hydromorphic paleosols formed within inshore parts of lakes and chernozem-type automorphic paleosol. The older horizon was formed during approximately 2500–1770 BP, and the younger one during approximately 1640–400 B P. The buried soils of the Subatlantic time period also attest to short episodes of lake regression. The climate changes show an evident trend: in the second part of the Atlantic time period it was warmer and drier than at present, and in the Subboreal and Subatlantic time periods the climate was cool and humid.
A Radiocarbon Age Calculation Program for Windows
Authors: Gallagher D , McGee E J , Mitchell P I
Published: July 2016

The management of counting files, the calculation of radiocarbon age, and the creation and maintenance of databases for storage and retrieval of laboratory data are time-consuming and exacting tasks. These routine functions are essential to the successful operation of all 14C dating laboratories. However, since the number of 14C dating laboratories worldwide is rather limited, it is unlikely that a commercial software company will produce a program for use in 14C age calculation and associated data management. We have therefore developed Windows based software to meet some of these needs.
Radiocarbon to Calendar Date Conversion: Calendrical Band Widths as a Function of Radiocarbon Precision
Authors: McCormac F. G. , Baillie M. G. L.
Published: July 2016

Accurate high-precision14C dating (i.e.,± 20 yr precision or less on the14C date) provides the narrowest calendrical band width and, hence, the best age range determination possible. However, because of the structure in the14C calibration curve, the calendar age range for a given14C precision is not constant throughout the calibration range. In this study, we quantify the calendar band widths for a range of14C precisions throughout the calibration range. We show that an estimate of the likely calendar band width in years can be obtained from the expression: Band width (yr) = 2.12 x14C precision (1 σ) + 54.6. We also show that calendar band widths are widest around 4000 BP at the start of the Bronze Age, and become narrow through the later Bronze Age and Iron Age and back into the Neolithic.
Comments on Sveinbjörnsdóttir Et Al. (2004) and The Settlement of Iceland
Authors: Olsson Ingrid U
Published: July 2016

Radiocarbon dates on samples aimed to date the settlement of Iceland are given together with comments by the laboratory, since many of the results and descriptions given by Sveinbjörnsdóttir et al. (2004) in Radiocarbon, together with new results, are in error. The intention of this paper is to present correct dates and further relevant information regarding samples used earlier and to discuss possible complications inherent in the method of Sveinbjörnsdóttir et al. (2004). Examples are given of how critical the collection, treatment, and interpretation of samples may be. An age difference between birch charcoal and grains for a site is expected due to various reasons. If the difference amounts up to ∼100 yr, as reported by Sveinbjörnsdóttir et al. (2004), it must only to a small degree be due to biological age. Reference to an excavation report, details regarding stratigraphy, and discussions of the risk for displacement and contamination are missing in their paper. A final evaluation of the time for settlement should not be done until more research is completed and other possible or earlier suggested or even dated sites are discussed. A summary is given of the research on the island and volcanic effects on the 14C activity of the atmospheric CO2, especially over Iceland.
The Lanergans in Performance
Authors: Smith Mary Elizabeth
Published: July 2016

For twenty years beginning in 1857, James West Lanergan owned and operated his own Dramatic Lyceum on King Square in uptown Saint John, New Brunswick. Each summer, with regularity, he returned with a dramatic company to produce the legitimate drama for an audience whose appreciation was shown in its faithful patronage. The result was a widespread and increasing enthusiasm for dramatic entertainment that, in 1872, spawned two more theatres: Bishop's Opera House for variety, and the far more elegant Academy of Music, whose well-equipped stage could accommodate the most modern requirements for spectacle. Lanergan's success in Saint John is undeniable. Appreciated as an artist by his audiences and by the press, and as a public-spirited gentleman by the citizenry, he made money as well as friends while he enlivened the cultural life of a city that was then enjoying unprecedented material prosperity.
Arthur McKee Rankin'sThe Danites1877–1881: Prime Example of the American Touring Process
Authors: Phillips Levi Damon
Published: July 2016

Having secured production rights to Joaquin Miller'sThe Danites; or,The Heart of the Sierras, actor-manager Arthur McKee Rankin presented it in the United States, Canada, and the British Isles during the years 1877–1881. Rankin's method of operation typified an important phase of a period Alfred Bernheim refers to as “the industrial revolution in the theatre.” In this phase the dominance of the combination system over the stock company evolved. Although the combination system was firmly established by the early 1870's, it was not until the end of the 1870's that disbandment of nearly all remaining provincial stock companies signaled the close of a theatrical era — the end of isolation and local independence — and stimulated a momentous increase in the number of combination companies on the road.
Matter far from the galactic plane associated with spiral arms
Authors: Oort J. H.
Published: July 2016

Neutral hydrogen concentrations were studied in the region between 48° and 200° longitude (new) and +6° and +20° latitude. Gas associated with individual arms beyond the sun has been found up to distances from 1 to 2 kpc from the galactic plane with an average density between 1 and 2% of that in the arm centres. The gas with the highest negative velocities shows a different behaviour. This has no counterpart in the plane, and it shows little or no concentration towards lower latitudes. Contrary to the hydrogen associated with the arms its distribution is highly asymmetrical. It does not seem to exist at negative latitudes. It may be of a similar origin as the high-velocity gas in high galactic latitudes near the sun.
Pulsar distances, spiral structure and the interstellar medium
Authors: Mills B. Y.
Published: July 2016

The distances of all pulsars are calculated on the assumption that they are immersed in a uniform medium of average electron density 0.06 cm−3. It then appears that the pulsars are concentrated towards the local and Sagittarius spiral features and that their mean height above the plane is consistent with that of known supernova remnants. The mean distances appear to be approximately correct, but individual distances are uncertain by about a factor of two. Evidence from radio continuum results supports this model of the ionized interstellar medium.
Remarks on local structure and kinematics
Authors: Blaauw A.
Published: July 2016

Attention is drawn to a few aspects of the state of motion of the local population which may become of importance for the study of local spiral structure. Uncertainties in the present knowledge of the local standard of rest are discussed, (a) with regard to the possible outward or inward motion with respect to the galactic centre, and (b) with regard to the component in the direction of circular motion. We furthermore draw attention to the quiet state of motion of the local interstellar gas and to the contrasting fairly high group velocities among the recently formed OB associations.
The galactic structure and the appearance of the Milky Way
Authors: Pavlovskaya E. D. , Sharov A. S.
Published: July 2016

The appearance of the Milky Way for an observer situated within our Galaxy is determined by the spatial distribution of stars and absorbing interstellar matter. Hence it may be hoped that the study of the surface brightness of the Milky Way permits to derive the spiral structure of our Galaxy.
A progress report on the Carina spiral feature
Authors: Bok B. J. , Hine A. A. , Miller E. W.
Published: July 2016

The existing data on the distribution of O and B stars, of optical and radio H II sources, of H I and of cosmic dust have been assembled for the Carina-Centaurus Section of the Milky Way, lII = 265° to 305°. The published data have been supplemented by recent photoelectric UBV data and new photographic material. Two Working Diagrams (Figures 9 and 10) of the Carina Spiral Feature have been prepared. The Feature is sharply bounded at lII = 282° and again at lII = 295° in the range of distance from 1.5 to 6 kpc from the sun. Its outer rim is observed from the sun almost tangentially to a distance of 8 kpc from the sun. The Feature is found to bend at distances greater than 9 to 10 kpc from the sun, a result shown by both radio H I and radio H II data.

Figure 9 presents our basic data for the stellar, gas and dust components of the Feature. The O and early B stars and the H II Regions are closely associated and within 6 kpc of the sun they are concentrated in the range 285° < lII < 295°. The distribution in longitude of H I is broader and spills over on both sides of the O and B and the H II peak distributions. Long period cepheids yield a concentration similar to that shown by O and B stars and H II Regions. The visual interstellar absorption between lII = 282° and 295° is represented by a value AV = 0.5 mag kpc−1, or less, applicable to distances of 4 to 5 kpc. Much higher absorption is present on the outside of the Carina Spiral Feature, 265° < lII < 280°, where total visual absorptions as great as 3.5 mags. are found at distances of the order of 2 kpc. Even heavier absorption is indicated for these longitudes at 4 kpc from the sun, thus suggesting that the heavy obscuration on the outside of the Carina Spiral Feature is a phenomenon of general structural relevance (see Figures 8 and 9). Only small values of AV are found at the inside of the Spiral Feature.

The Working Diagram (Figure 10) shows that the O and B star peak and the H II peak have a width of 800 parsecs (12°) at 4 kpc from the sun, whereas the H I width is at least 1500 parsecs at the same distance. The peak of the O and B star distribution and of the H II distribution lies at about 600 parsecs (8° at 4 kpc) within the outer edge of the spiral feature. The heaviest interstellar absorption is on the outside of the Feature.
Photometric and spectroscopic data for some distant O and B stars
Authors: Lyngå G.
Published: July 2016

The open cluster Stock 16 and some distant OB stars in Crux have been studied. Lack of absorption between spiral arms -I and -II is apparent. Negative residual radial velocities are found at distances of about 6 kpc at lII = 298°.
Progress report on the Cleveland-Chile survey for southern OB stars
Authors: Stephenson C. B. , Sanduleak N.
Published: July 2016

From some standpoints it should seem surprising that not all of the OB stars of our Galaxy that can be identified to a feasible limiting magnitude (say 12–13) by conventional objective prism techniques have yet been so identified, but this is in fact the state of our published data. Some people here will recall that such a systematic survey for the northern Milky Way was carried out several years ago jointly by the Hamburg and Warner and Swasey Observatories. Now at the Warner and Swasey Observatory we are extending this northern survey into the southern Milky Way that could not be reached from the north, and we are making this extension as homogeneous as possible with respect to the northern survey.
Stellar rings and galactic structure
Authors: Isserstedt J.
Published: July 2016

Stellar rings are shell type prolate ellipsoidal stellar aggregates. The most important property is the constancy of the minor diameters which allows precise geometric distance determinations up to great distances. New photoelectric and photographic UBV-observations of two stellar rings confirm the reality and the diameter constancy of these objects. All A- and F-stars of a nearby ring in Aquila exhibit an UV-excess, similar to that observed in the very young open cluster NGC 2264.
On the distribution of space velocities of OB stars
Authors: Mirzoyan L. V. , Mnatsakanian M. A.
Published: July 2016

OB stars, as the most typical members of O-associations, are of great interest for the problems of stellar evolution. Their concentration in spiral arms indicates the importance of the O-associations for the formation of the spiral arm population in galaxies.
The theory of spiral structure of galaxies
Authors: Marochnik L. S.
Published: July 2016

A Landau-type instability mechanism for generating spiral waves is suggested.

Two populations of stars, Populations I and II, are considered, the second one with mean rotational velocity zero. Then a dispersion relation is derived which is reduced to the Lin-Shu dispersion relation in the case of vanishing Population II. The amplification of the wave is of the same type as the two-stream instability. It occurs if the angular velocity of the spiral pattern Ωs is smaller than the angular velocity of the Population I stars. A value of Ωs = 22–25 km s−1 kpc−1 was found, as well as the growth parameter. Spiral arms are formed in 108–109 yr, while trailing and leading waves grow at the same rate.

A quasi-linear theory is developed to account for the limited growth of the spiral waves.

Detailed accounts of the theory and of its implications are contained in recent publications (Marochnik, 1969; Marochnik and Suchkov, 1969a; 1969b; Marochnik and Ptitzina, 1969; Marochnik et al., 1969).
Large scale oscillations of galaxies
Authors: Hunter C.
Published: July 2016

The observational evidence that may indicate the presence of large scale modes of oscillation in galaxies is reviewed, and some results of theoretical modal calculations are described.
Density waves in galaxies of finite thickness
Authors: Vandervoort P. O.
Published: July 2016

The effect of the finite thickness of a galaxy on the propagation of density waves of the type described by Lin and his collaborators has been calculated. The calculated effect does not differ appreciably from what has been estimated previously on the basis of heuristic arguments.
Barred spiral galaxies
Authors: Freeman K. C.
Published: July 2016

We point out some properties of barred spiral galaxies which are important for the theory of their formation and spiral structure, and describe some theoretical work on the dynamics of these systems.
Local magnetic field and its relations to the local spiral arm structure
Authors: Verschuur G. D.
Published: July 2016

No paper was submitted.
Polarization of southern OB-stars
Authors: Klare G. , Neckel T.
Published: July 2016

The polarization data of 1421 southern OB-stars of the Heidelberg catalogue have been measured and plotted in a galactic lII, bII-diagram. For some longitude intervals the relationship of the standard deviation of the electric vector alignment and the galactic longitude was computed.
Correlations of Globular Cluster Properties as Constraints for Dynamical Evolution Models
Authors: Djorgovski S.G.
Published: July 2016

Correlations between globular cluster (GC) properties are reviewed, including some new work on cluster tidal radii and densities. Most of the observed correlations can be interpreted within the framework of our current understanding of their dynamical evolution. These correlations provide empirical constraints for models of GC formation and evolution.
HST Observations of the Globular Cluster M4
Authors: Fahlman G. G. , Richer H.B. , Ibata R.I. , Ivanans N.C. , Mandushev G. , Hesser J.E. , Stetson P.B. , Wood M. A. , Vandenberg D.A. , Pryor C. , Harris W.E. , Bond H.E. , Bolte M. , Bell R.A.
Published: July 2016

The WFPC2 aboard the Hubble Space Telescope has been used to obtain deep images in three fields at different radial positions in the nearest Globular cluster, M4 (NGC 6121). In this paper, we discuss the white dwarf cooling sequence and show how the dynamical structure of the cluster will affect their cumulative distribution function. We also present the first discussion of our observations of the faint cluster main sequence stars.
Lives of Hierarchical Triple Systems in Clusters and in the Field
Authors: Kiseleva Ludmila G.
Published: July 2016

Evolution with time of isolated hierarchical triple stars, stable from a dynamical point of view, is studied using analytical and numerical approaches. The results are applied to the study of the evolutionary cycle of hierarchical systems formed by dynamical capture in open clusters (up to 10,000 stars).
Frequency of Stellar Collisions in Three-Body Heating
Authors: Chernoff David F. , Huang Xiaolan
Published: July 2016

The probability for collisional interaction of three body binaries is calculated as a function of the physical radius and mass of the stellar objects and the depth of the cluster potential well. For typical cluster parameters, there is a significant chance of physical collision for objects as small as white dwarfs. One consequence of the collisions is to lower the amount of heat produced from hardening a binary, thereby diminishing the efficiency of the three-body heating mechanism.
Dynamics of Galactic Nuclei Containing Massive Remnant Stars
Authors: Lee H. M.
Published: July 2016

We have examined the dynamical evolution of stellar system containing massive remnant stellar component. If individual mass of remnant stars is much heavier than that of normal stars which comprise most of the mass in the cluster, remnant stars quickly form a subsystem within the core of cluster of ordinary stars. The subsystem evolves on its own relaxation time scale which is very short. However, the post collapse expansion driven by the three-body binary heating becomes very slow because the expansion energy of the compact subcluster can be easily absorbed by surrounding cluster. The gravitational radiation can lead to the merger of binaries when binaries become very hard. A central seed black hole might form if repeated merger becomes very efficient. Otherwise, relatively stable two-component phase of central compact cluster of remnant stars surrounded by larger cluster of low mass stars would last for a long time.
Dark Matter in Globular Clusters
Authors: Heggie Douglas C. , Hut Piet
Published: July 2016

We first review reasons why dark matter is an interesting issue in connection with star clusters. Next we consider to what extent the presence of dark matter is consistent with their dynamics and structure. We review various model-dependent and model-independent methods which have been applied to two well studied clusters, NGC 6397 and 47 Tuc. We suggest that about half of the mass in each object is still unobserved, possibly in the form of a mixture of low-mass stars and white dwarfs.
Adaptive Optics NIR Imaging of R136 in 30 Doradus: The Stellar Population of a Nearby Starburst
Authors: Brandl B. , Sams B.J. , Bertoldi F. , Eckart A. , Genzel R. , Drapatz S. , Hofmann R. , Löwe M. , Quirrenbach A.
Published: July 2016

The center of the stellar association in 30 Doradus, R136 (HD 38268), is an unusually high concentration of massive and bright O, B and Wolf-Rayet stars and represents the closest example of an intense starburst region.
A Search for Variables in the Central Regions of Southern Globular Clusters
Authors: Menzies J. W.
Published: July 2016

Preliminary results are presented for 3 southern globular clusters that have been searched via CCD photometry for new short-period variables that might be associated with blue stragglers. The clusters considered here are NGC6121, NGC3201 and NGC6809.
The Fate of Binary Systems After the Explosion of SNe 1993J and 1994I
Authors: Yamaoka Hitoshi
Published: July 2016

The kinematics of the binary systems to which supernovae(SNe) 1993J and 1994I belonged are studied. The kick velocity caused by supernova(SN) asymmetry will highly influence the fate of the system. The survival rates with assumed kick velocity distribution are discussed.
Time-Symmetrized Kustaanheimo-Stiefel Regularization
Authors: Funato Yoko , Makino Junichiro , Hut Piet , McMillan Steve
Published: July 2016

In this paper, we show a new algorithm to integrate the orbits of binaries. Our new algorithm has the good properties of both symmetrized timesteps and KS regularization: (1) no secular error in either energy or angular momentum; (2) a constant number of timesteps per orbit for a binary with arbitrary eccentricity (Funato et al., 1995).
A Numerical Approximation for Hierarchical Triples
Authors: Heggie Douglas C.
Published: July 2016

This paper describes a numerical method for following the evolution of the orbit of a perturbed binary (e.g. the inner binary of a hierarchical triple) by means of averaging.
Dynamical Evolution of Rotating Globular Clusters
Authors: Longaretti P.-Y. , Lagoute C.
Published: July 2016

We have computed simplified globular cluster evolutionary tracks which take into account the effects of internal relaxation, of the cluster rotation, of the galactic tidal field, and, in a cruder way, of stellar evolution and of gravitational shocking. The objectives are first to quantify the influence of rotation in the dynamical evolution of globular clusters; and second, to investigate the evolution of globular cluster angular momentum and flattening (Lagoute and Longaretti 1995a, Longaretti and Lagoute 1995b,c).
A Proper-Motion Search for Dwarf Carbon and S Stars
Authors: MacConnell D. J. , Williamson R. L. , Roberts W. J.
Published: July 2016

We report on an effort to identify further members of the dwarf carbon class and new members of a putative dwarf S group in the general field through determination of proper motions of catalogued stars. Examination of nearly 1500 C stars and over 300 S stars reveals some interesting false alarms but no new dwarf members of these classes.
Surveys for Carbon Stars in External Galaxies
Authors: Azzopardi Marc
Published: July 2016

Prominent molecular absorption bands in the spectra of carbon stars make their detection possible, even in relatively distant external galaxies. Although extensive surveys for carbon stars have been carried out mainly in the Magellanic Clouds and the dwarf spheroidals in the Galactic halo, more distant galaxies in the Local Group and beyond have been successfully searched for this kind of object.
Model Atmospheres for Normal and Peculiar Red Giant Stars
Authors: Plez Bertrand
Published: July 2016

I review the current status of model atmospheres for red giants, with special emphasis on recent progress and newer grids. I draw attention to some specific problems regarding opacity sources and present current and forthcoming efforts in cool-star atmospheric modeling.