1,160 research outputs found

    Proper Motions of H-alpha filaments in the Supernova Remnant RCW 86

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    We present a proper motion study of the eastern shock-region of the supernova remnant RCW 86 (MSH 14-63, G315.4-2.3), based on optical observations carried out with VLT/FORS2 in 2007 and 2010. For both the northeastern and southeastern regions, we measure an average proper motion of H-alpha filaments of 0.10 +/- 0.02 arcsec/yr, corresponding to 1200 +/- 200 km/s at 2.5kpc. There is substantial variation in the derived proper motions, indicating shock velocities ranging from just below 700 km/s to above 2200 km/s. The optical proper motion is lower than the previously measured X-ray proper motion of northeastern region. The new measurements are consistent with the previously measured proton temperature of 2.3 +/- 0.3 keV, assuming no cosmic-ray acceleration. However, within the uncertainties, moderately efficient (< 27 per cent) shock acceleration is still possible. The combination of optical proper motion and proton temperature rule out the possibility that RCW 86 has a distance less than 1.5kpc. The similarity of the proper motions in the northeast and southeast is peculiar, given the different densities and X-ray emission properties of the regions. The northeastern region has lower densities and the X-ray emission is synchrotron dominated, suggesting that the shock velocities should be higher than in the southeastern, thermal X-ray dominated, region. A possible solution is that the H-alpha emitting filaments are biased toward denser regions, with lower shock velocities. Alternatively, in the northeast the shock velocity may have decreased rapidly during the past 200yr, and the X-ray synchrotron emission is an afterglow from a period when the shock velocity was higher.Comment: Accepted for publication in MNRA

    Representing or defecting ? : the pursuit of individual upward mobility in low status groups

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    This dissertation investigated the conditions under which the individual upward mobility of mem-bers of low status groups is likely to succeed and when it is likely to meet resistance. In addition, it examines how upwardly mobile individuals can create such beneficial conditions. The results presented in this dissertation show support from fellow members of the low status group to be a key resource. Such ingroup support enables members of low status groups to persevere in the pursuit of individual upward mobility, even in the face of opposition from the high status outgroup. The results indicate that ingroup support is given to individuals the more they are perceived to represent the ingroup with their upward mobility. Moreover, the extent to which upwardly mobile individuals are perceived as representatives depends on how they associate with the low status ingroup. The results also show that the degree to which upwardly mobile individuals display their association with the low status group affects whether they meet resistance from the outgroup. While the high status outgroup is concerned about behavioral displays, it is less concerned with affective identification of upwardly mobile individuals of low status groups with their group. Explanations of these effects are offered.LEI Universiteit LeidenNWOSocial decision makin

    High- and low energy nonthermal X-ray emission from the cluster of galaxies A 2199

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    We report the detection of both soft and hard excess X-ray emission in the cluster of galaxies A 2199, based upon spatially resolved spectroscopy with data from the BeppoSAX, EUVE and ROSAT missions. The excess emission is visible at radii larger than 300 kpc and increases in strength relative to the isothermal component. The total 0.1-100 keV luminosity of this component is 15 % of the cluster luminosity, but it dominates the cluster luminosity at high and low energies. We argue that the most plausible interpretation of the excess emission is an inverse Compton interaction between the cosmic microwave background and relativistic electrons in the cluster. The observed spatial distribution of the non-thermal component implies that there is a large halo of cosmic ray electrons between 0.5-1.5 Mpc surrounding the cluster core. The prominent existence of this component has cosmological implications, as it is significantly changing our picture of a clusters's particle acceleration history, dynamics between the thermal and relativistic media, and total mass budgets.Comment: Accepted for publication in Astrophysical Journal, Letter

    Clinical validation of Anyplex? II HPV HR Detection according to the guidelines for HPV test requirements for cervical cancer screening.

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    BACKGROUND: Anyplex? II HPV HR Detection (Seegene, Seoul, Korea) is a multiplex real-time PCR using tagging oligonucleotide cleavage and extension (TOCE) technology for simultaneous detection and genotyping of 14 high-risk (HR) HPV types, including HPV16 and HPV18. OBJECTIVES: To evaluate whether the clinical performance and reproducibility of Anyplex? II HPV HR Detection meet the international consensus guidelines for HPV test requirements for cervical cancer screening [1]. STUDY DESIGN: The clinical performance of Anyplex? II HPV HR Detection for detecting cervical intraepithelial neoplasia grade 2 or worse (CIN2+) was determined relative to that of the reference assay, i.e., HR HPV GP5+/6+-PCR-EIA, by analysis of a total of 879 cervical liquid based cytology (LBC) specimens from a screening population, of which 60 were from women with CIN2+. The intra-laboratory reproducibility and inter-laboratory agreement were determined on 509 LBC samples, of which 172 were positive by the reference assay. RESULTS: Anyplex? II HPV HR Detection showed a clinical sensitivity for CIN2+ of 98.3% (59/60; 95% CI: 89.1-99.8) and a clinical specificity for CIN2+ of 93.6% (764/816; 95% CI: 89.8-96.1). The clinical sensitivity and specificity were non-inferior to those of HR HPV GP5+/6+-PCR-EIA (non-inferiority score test: P=0.005 and P=0.023, respectively). Both intra-laboratory reproducibility (96.8%; 95% CI: 95.3-98.1; kappa value of 0.93) and inter-laboratory agreement (96.0%; 95% CI: 94.3-97.4; kappa value of 0.91) were high. CONCLUSIONS: Anyplex? II HPV HR Detection performs clinically non-inferior to HR HPV GP5+/6+-PCR-EIA. Anyplex? II HPV HR Detection complies with international consensus validation metrics for HPV DNA tests for cervical cancer screening [1]

    The Radial Structure of the Cygnus Loop Supernova Remnant --- Possible evidence of a cavity explosion ---

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    We observed the North-East (NE) Limb toward the center region of the Cygnus Loop with the ASCA Observatory. We found a radial variation of electron temperature (kTe) and ionization timescale (log(\tau)) whereas no variation could be found for the abundances of heavy elements. In this paper, we re-analyzed the same data set and new observations with the latest calibration files. Then we constructed the precise spatial variations of kTe, log(\tau), and abundances of O, Ne, Mg, Si, and Fe over the field of view (FOV). We found a spatial variation not only in kTe and in log(\tau) but also in most of heavy elements. As described in Miyata et al. (1994), values of kTe increase and those of log(\tau) decrease toward the inner region. We found that the abundance of heavy elements increases toward the inner region. The radial profiles of O, Ne, and Fe show clear jump structures at a radius of 0.9 Rs, where Rs is the shock radius. Outside of 0.9 Rs, abundances of all elements are constant. On the contrary, inside of 0.9 Rs, abundances of these elements are 20--30 % larger than those obtained outside of 0.9 Rs. The radial profile of kTe also shows the jump structure at 0.9 Rs. This means that the hot and metal rich plasma fills the volume inside of 0.9 Rs. We concluded that this jump structure was the possible evidence for the pre-existing cavity produced by the precursor. If the ejecta fills inside of 0.9 Rs, the total mass of the ejecta was roughly 4\Msun. We then estimated the main-sequence mass to be roughly 15\Msun, which supports the massive star in origin of the Cygnus Loop supernova remnant and the existence of a pre-existing cavity.Comment: 37 pages, 14 figures. Accepted for publication of Ap
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