AMBER and CRIRES observations of the binary sgB[e] star HD 327083: evidence of a gaseous disc traced by CO bandhead emission

HD 327083 is a sgB[e] star that forms a binary system with an orbital semi-major axis of ~1.7 AU. Our previous observations using the VLTI and AMBER in the medium resolution K-band mode spatially resolved the environment of HD 327083. The continuum visibilities obtained indicate the presence of a circumbinary disc. CO bandhead emission was also observed. However, due to the limited spectral resolution of the previous observations, the kinematic structure of the emitting material was not constrained. In this paper, we address this and probe the source of the CO emission with high spectral resolution and spatial precision. We have observed HD 327083 with high spectral resolution (25 & 6 km/s) using AMBER and CRIRES. The observations are compared to kinematical models to constrain the source of the emission. It is shown that the CO bandhead emission can be reproduced using a model of a Keplerian disc with an inclination and size consistent with our previous VLTI observations. The model is compared to AMBER differential phase measurements, which have a precision as high as 30-micro-arcseconds. A differential phase signal corresponding to 0.15 milli-arcseconds (~5 sigma) is seen over the bandhead emission, which is in excellent agreement with the model that fits the CRIRES observations. In comparison, a model of an equatorial outflow, as envisaged in the standard sgB[e] scenario, does not reproduce the observations well. The excellent agreement between the disc model and observations in the spatial and spectral domains is compelling evidence that the CO bandhead emission of HD 327083 originates in a circumbinary Keplerian disc. In contrast, the model of an equatorial outflow cannot reproduce the observations well. This suggests that the standard sgB[e] scenario is not applicable to HD 327083, which supports the hypothesis that the B[e] behaviour of HD 327083 is due to binarity (ABRIDGED).Comment: Accepted for publication in A&

The Role of Family Functioning in the Association Between Childhood Sexual Victimization and Substance Use in Non-treatment Populations: Results from a Native Canadian Community and Comparisons with the General Population

Using path analytic techniques, this study examines the relationship between childhood sexual victimization and alcohol consumption in adult life, focusing in particular on the role of family functioning and the surrounding social support network of family and friends. Two non-treatment populations are compared, one, an Ontario Native community, and the other, the general Ontario population. The models are estimated separately for males and females. While the results for the two samples differ significantly in certain respects (including by sex), the importance of family functioning as an intervening factor is apparent for both Natives and non-Natives. The results of the path analyses for the two samples suggest that, among the Native group, sexual abuse is significantly and positively related to alcohol consumption through the family dysfunction measure for both males and females and through non-family support for females alone. In the general population sample, conversely, none of the three social support measures tested link sexual abuse to alcohol consumption. Instead, quality of parental relationships appears relatively more important among males in particular in predicting level of family dysfunction and supportive relations with family. These findings provide limited support for the hypothesized mediating influence of the informal support network in the relationship of childhood sexual victimization to substance abuse outcomes; they also point to notable differences for males and females in the dynamics of family life and substance use. The comparability of the Native and non-Native populations with respect to prevalence estimates and implications of the findings for policy are discussed

Determinants of the Risk and Timing of Alcohol and Illicit Drug Use Onset Among Natives and Non-natives: Similarities and Differences

Objective: Employing probability samples from the Ontario Health Survey Supplement (Ontario Ministry of Health, 1990/91) and a community of Native Ontario reserve residents (Embree, 1993), this study compared and contrasted Natives\u27 and Non-natives\u27 determinants of drug and alcohol use onset. Method: Proportional Hazards techniques identified factors associated with the risk and timing of onset of substance use (alcohol and illicit drugs) for both cultural groups, and special attention was paid to the role of family background characteristics as precursors to early alcohol and drug-use onset. Results: The multivariate results reveal that, for both Natives and Non-natives alike, and considering both drinking and drug use onset together, age cohort predominates as a risk factor, with youngest groups at greatest risk, and especially in the case of drug use other than alcohol. Males also exhibit consistently higher risks of both alcohol and other substance use, and this is true to a greater extent for Non-natives. For the model of drug use timing, age of alcohol use onset is the second best predictor for Natives, although its effect is still apparent, albeit weaker, in the case of Non-natives. The results concerning age at first regular drinking lend further support to previous findings that alcohol use is a powerful predisposing factor to the use of illicit substances. However, the evident cultural disparity in the predictive power of this measure also suggests that Natives may lag behind the general population with respect to recently observed shifts in the pattern of substance use progression (i.e., away from alcohol use as a necessary precondition to illicit use of other drugs). As for family characteristics, a number of factors emerge as determinants of risk but appear to depend, at least in part, on the cultural group and the substance under consideration: namely, parental substance abuse, paternal history of depression, quality of parental relations, parental occupational background, and sexual abuse during childhood. Conclusions: Overall, the findings point to the salience of family background in affecting early onset drinking and drug use, behaviors well-recognized to have potentially adverse mental and physical health consequences, as well as negative social outcomes

Rigid N=2 superconformal hypermultiplets

We discuss superconformally invariant systems of hypermultiplets coupled to gauge fields associated with target-space isometries.Comment: Invited talk given at the International Seminar "Supersymmetries and Quantum Symmetries", July 1997, Dubna. Latex, 9 p

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The resolution at which foraminiferal stable isotopes are applied in paleo-environmental studies is ever increasing, resulting in continuous sampling of sediment cores. The resolution of such continuously sampled records depends on the rate of sedimentation of foraminiferal shells in its relation to the intensity of bioturbation. Bioturbation essentially mixes sediment layers of different age, altering the primary climate signal, thereby impacting the accuracy of both the timing and magnitude of reconstructed climate changes. A new approach to assess and correct the impact of bioturbation is investigated here, based on the δ18O of individual specimens of planktonic foraminifera Globorotalia inflata from a series of boxcore samples in the Eastern North Atlantic. Average δ18O values decrease southward from 1.62 to 1.07‰ with the exception of site T86-11 (1.35‰). The δ18O distribution of each station can be fitted with a uni- to polymodal distribution. A nonunimodal distribution strongly suggests admixing of bioturbated individuals. Quantification of these distributions allows deconvolving the original and bioturbated signals and subsequently provides a correction for bioturbation. © 2013. American Geophysical Union. All Rights Reserved

A Massive S-duality in 4 dimensions

We reduce the Type IIA supergravity theory with a generalized Scherk-Schwarz ansatz that exploits the scaling symmetry of the dilaton, the metric and the NS 2-form field. The resulting theory is a new massive, gauged supergravity theory in four dimensions with a massive 2-form field and a massive 1-form field. We show that this theory is S-dual to a theory with a massive vector field and a massive 2-form field, which are dual to the massive 2-form and 1-form fields in the original theory, respectively. The S-dual theory is shown to arise from a Scherk-Schwarz reduction of the heterotic theory. Hence we establish a massive, S-duality type relation between the IIA theory and the heterotic theory in four dimensions. We also show that the Lagrangian for the new four dimensional theory can be put in the most general form of a D=4, N=4 gauged Lagrangian found by Schon and Weidner, in which (part of) the SL(2) group has been gauged.Comment: 20 pages, references adde

Probing discs around massive young stellar objects with CO first overtone emission

We present high resolution (R~50,000) spectroastrometry over the CO 1st overtone bandhead of a sample of seven intermediate/massive young stellar objects. These are primarily drawn from the red MSX source (RMS) survey, a systematic search for young massive stars which has returned a large, well selected sample of such objects. The mean luminosity of the sample is approximately 5 times 10^4 L_\odot, indicating the objects typically have a mass of ~15 solar masses. We fit the observed bandhead profiles with a model of a circumstellar disc, and find good agreement between the models and observations for all but one object. We compare the high angular precision (0.2-0.8 mas) spectroastrometric data to the spatial distribution of the emitting material in the best-fitting models. No spatial signatures of discs are detected, which is entirely consistent with the properties of the best-fitting models. Therefore, the observations suggest that the CO bandhead emission of massive young stellar objects originates in small-scale disks, in agreement with previous work. This provides further evidence that massive stars form via disc accretion, as suggested by recent simulations.Comment: Accepted for publication in MNRA