NBC News Scripts
WBAP-TV (Television station : Fort Worth, Tex.)
1954-12-31
Search results
16 records were found.
The international reputation of a university is heavily based on the quality and influence of its research and hence the competence of its researchers. To provide support and enable the research community, an university library needs to have a good understanding of their current needs, and insight into areas for future support. To gain this information, a survey of Massey University researchers was undertaken by the Library in 2014. The survey instrument was based on the Research Libraries UK (RLUK) Re-skilling for Research report and used a ranking scale response to statements of current and potential areas of support through the stages of the research life cycle. The data was further analysed according to respondents’ faculties and their career stages to highlight specific areas that needed to be addressed. Traditional academic libra...
We present radio and submillimetre observations of the O4I(n)f star zeta Pup, and discuss structure in the outer region of its wind (similar to10-100 R-*). The properties of bremsstrahlung, the dominant emission process at these wavelengths, make it sensitive to structure and allow us to study how the amount of structure changes in the wind by comparing the fluxes at different wavelengths. Possible forms of structure at these distances include Corotating Interaction Regions (CIRs), stochastic clumping, a disk or a polar enhancement. As the CIRs are azimuthally asymmetric, they should result in variability at submillimetre or radio wavelengths. To look for this variability, we acquired 3.6 and 6 cm observations with the Australia Telescope Compact Array (ATCA), covering about two rotational periods of the star. We supplemented these wit...
We present Far Ultraviolet Spectroscopic Explorer (FUSE) satellite time-series data of the low-inclination, nova-like cataclysmic variable RW Sex. The data span the wavelength range between similar to905 and 1188 Angstrom, which contains the resonance lines of C III, N III, S IV, P V, S VI and O VI. All these spectral lines are present in the form of blueshifted absorption components, with no evidence for the lines redward of rest velocity; the FUSE data probe the fast disc-wind of RW Sex. The time-variable nature of these features is established. Substantial line profile variability is observed, confined between similar to-1000 and 0 km s(-1), and modulated on the orbital period of the system (similar to0.245 d). The fundamental characteristics of the temporal behaviour are very similar between the low and high ionization lines. The w...
We present the results of a detailed non-LTE analysis of the ultraviolet and optical spectrum of the O6.5 Iaf(+) star HD 153919 - the mass donor in the high-mass X-ray binary 4U1700-37. We find that the star has a luminosity log(L-*/L-.) = 5.82 +/- 0.07, T-eff = 35 000 +/- 1000 K, radius R-* = 21.9(-0.5)(+1.3) R-., mass-loss rate (M) over dot = 9.5 x 10(-6) M-. yr(-1), and a significant overabundance of nitrogen (and possibly carbon) relative to solar values. Given the eclipsing nature of the system these results allow us to determine the most likely masses of both components of the binary via Monte Carlo simulations. These suggest a mass for HD 153919 of M-* = 58 +/- 11 M-.. - implying the initial mass of the companion was rather high (greater than or similar to60 M-.). The most likely mass for the compact companion is found to be M-x...
Mass-loss in massive stars plays a critical role in their evolution, although the precise mechanism(s) responsible - radiatively driven winds, impulsive ejection and/or binary interaction -remain uncertain. In this paper we present ALMA line and continuum observations of the supergiant B[e] star Wd1-9, a massive post-Main Sequence object located within the starburst cluster Westerlund 1. We find it to be one of the brightest stellar point sources in the sky at millimetre wavelengths, with (serendipitously identified) emission in the H41alpha radio recombination line. We attribute these properties to a low velocity (~100 km/s) ionised wind, with an extreme mass-loss rate 6.4x10^-5(d/5kpc)^1.5 Msol/yr. External to this is an extended aspherical ejection nebula indicative of a prior phase of significant mass-loss. Taken together, the mill...
We present a compilation of spectroscopic observations of the sgB[e] star CI Cam, the optical counterpart of XTE J0421+560. This includes data from before, during, and after its 1998 outburst, with quantitative results spanning 37 years. The object shows a rich emission line spectrum originating from circumstellar material, rendering it difficult to determine the nature of either star involved or the cause of the outburst. We collate all available pre-outburst data to determine the state of the system before this occurred and provide a baseline for comparison with outburst and post-outburst data. During the outburst all lines become stronger, and hydrogen and helium lines become significantly broader and asymmetric. After the outburst, spectral changes persist for at least three years, with Fe II and [N II] lines still a factor of simi...
Aims. We analyze the multiplicity properties of the massive O-type star population. With 360 O-type stars, this is the largest homogeneous sample of massive stars analyzed to date. Methods. We use multi-epoch spectroscopy and variability analysis to identify spectroscopic binaries. We also use a Monte-Carlo method to correct for observational biases. Results. We observe a spectroscopic binary fraction of 0.35\pm0.03, which corresponds to the fraction of objects displaying statistically significant radial velocity variations with an amplitude of at least 20km/s. We compute the intrinsic binary fraction to be 0.51\pm0.04. We adopt power-laws to describe the intrinsic period and mass-ratio distributions: f_P ~ (log P)^\pi\ (with 0.15 < log P < 3.5) and f_q ~ q^\kappa\ with 0.1 < q=M_2/M_1 < 1.0. The power-law indexes that best reproduce t...
© 2016 John Wiley & Sons Ltd. We synthesize insights from current understanding of drought impacts at stand-to-biogeographic scales, including management options, and we identify challenges to be addressed with new research. Large stand-level shifts underway in western forests already are showing the importance of interactions involving drought, insects, and fire. Diebacks, changes in composition and structure, and shifting range limits are widely observed. In the eastern US, the effects of increasing drought are becoming better understood at the level of individual trees, but this knowledge cannot yet be confidently translated to predictions of changing structure and diversity of forest stands. While eastern forests have not experienced the types of changes seen in western forests in recent decades, they too are vulnerable to drough...
