Hepatitis C virus.

Pereira, Chrystopher A.M.; Lee, C A; Dusheiko, GM

doi:10.1136/bmj.303.6805.783

Cited by 8 publications

(5 citation statements)

References 7 publications

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“…• 8 ± 1. • 7 (Harries & Howarth 1996, 2000, P orb = 624.5 d and v sin i = 7 ± 1 km s −1 (Schmutz et al 1994; Pereira, Vogel & Nussbaumer 1995). We calculate P rot ≈ 830−1230 d. [If we use R g ≈ 80 R (see Section 4.3), we get P rot ≈ 480−705 d, a range which includes the orbital period.]…”

Section: Objects With Known Periods Not Observed By Usmentioning

confidence: 93%

Rotational velocities of the giants in symbiotic stars - II. Are S-type symbiotics synchronized?★

Zamanov

Bode

Melo

et al. 2007

Monthly Notices of the Royal Astronomical Society

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We have measured the projected rotational velocities (v sin i) of the mass donors for 29 S‐type symbiotic stars (SSs) using high‐resolution spectroscopic observations and the cross‐correlation function (CCF) method. The results of the CCF have been controlled with synthetic spectra. The typical rotational velocity of the K and M giants in S‐type symbiotics appeared to be 4.5 < v sin i < 11.7 km s−1. In a subsample of 16 S‐type SSs (with known orbital periods and well‐measured v sin i), 15 have deviations from synchronization less than the 3σ level. This means that we did not find evidence for a statistically significant deviation from the synchronization for any of these 15 objects. The deviation from synchronization is statistically significant (at confidence level >99 per cent) only for the recurrent nova RS Oph. For 22 S‐type symbiotics we give clues as to what their orbital periods could be.

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Section: Objects With Known Periods Not Observed By Usmentioning

confidence: 93%

Rotational velocities of the giants in symbiotic stars - II. Are S-type symbiotics synchronized?★

Zamanov

Bode

Melo

et al. 2007

Monthly Notices of the Royal Astronomical Society

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“…There has been much observational work on symbiotic systems, showing that complicated kinematics is responsible for variabilities and complex structures in the line profiles (e.g. Mueller & Nussbaumer 1985, Pereira et al 1995. We do not attempt to give a detailed dynamical model in this work, but adopt rather simple models in order to find out the main features contributing to the polarization structures and the profiles in the Raman scattered lines (e.g.…”

Section: Modelmentioning

confidence: 99%

“…Valuable kinematic information on the emission nebula of a symbiotic system is obtained in a detailed analysis of the profiles of the emission lines, which often accompany non-trivial structures including double-peaked or partial absorption troughs (e.g. Mueller & Nussbaumer 1985, Pereira et al 1995. The Raman scattered features can provide a useful diagnostic to constrain many kinematical parameters of a symbiotic system, because they have broadened profiles due to the relative motion of the stellar wind around the cool giant with respect to the emission nebula.…”

Section: Introductionmentioning

confidence: 99%

On the profiles and the polarization of Raman-scattered emission lines in symbiotic stars -- II. Numerical simulations

Lee

1997

Monthly Notices of the Royal Astronomical Society

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A Monte Carlo method is used to calculate the profiles and the polarization of the Raman scattered O VI lines (λλ6827, 7088) in symbiotic stars, which are believed to be a binary system of a cool giant and a hot star with an emission nebula around it. A point-like isotropic UV radiation source is assumed and a simple spherical wind model is adopted for the kinematics of the scattering material from the cool giant.We first investigate the case where the incident line photons are described by a Gaussian profile having a width of 10 4 K. We subsequently investigate the effects of the extended ionized region and non-spherical wind models including a disk-type wind and a bipolar wind. The cases where the emission source is described by non-Gaussian profiles are briefly studied.Finally as an additional component for the kinematics of symbiotic stars the orbital motion of the hot component around the cool giant is included and the effect on the spectropolarimetry is investigated. In this case the polarization direction changes around the red part of the Raman-scattered emission lines, when the observer's line of sight is perpendicular to the orbital plane, and no such effect is seen when the line of sight lies in the orbital plane. Furthermore, complex peak structures are seen in the degree of polarization and the polarized flux, which have often been observed in several symbiotic systems including RR Tel.Brief observational consequences and predictions are discussed in relation to the present and future spectropolarimetry for symbiotic stars. It is concluded that spectropolarimetry may provide a powerful diagnostic of the physical conditions of symbiotic stars.

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“…Their profile along the orbit can be compared to a sine function (for SY Mus, see Fig. 2 of Pereira et al 1995;Skopal 2009).…”

Section: Components Of the Continuum Radiationmentioning

confidence: 99%

Wind asymmetry imprint in the UV light curves of the symbiotic binary SY Mus

Shagatova

Skopal

2017

A&A

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Context. Light curves (LCs) of some symbiotic stars show a different slope of the ascending and descending branch of their minimum profile. The origin of this asymmetry is not understood well. Aims. We explain this effect in the ultraviolet LCs of the symbiotic binary SY Mus. Methods. We model the continuum fluxes in the spectra obtained by the International Ultraviolet Explorer at 10 wavelengths, from 1280 to 3080 Å. We consider that the white dwarf radiation is attenuated by H 0 atoms, H − ions and free electrons in the red giant wind. Variation in the nebular component is approximated by a sine wave along the orbit as suggested by spectral energy distribution models. The model includes asymmetric wind velocity distribution and the corresponding ionization structure of the binary. Results. We determined distribution of the H 0 and H + , as well as upper limits of H − and H 0 column densities in the neutral and ionized region at the selected wavelengths as functions of the orbital phase. Corresponding models of the LCs match well the observed continuum fluxes. In this way, we suggested the main UV continuum absorbing (scattering) processes in the circumbinary environment of S-type symbiotic stars. Conclusions. The asymmetric profile of the ultraviolet LCs of SY Mus is caused by the asymmetric distribution of the circumstellar matter at the near-orbital-plane area.

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Hepatitis C virus.

Cited by 8 publications

References 7 publications

Rotational velocities of the giants in symbiotic stars - II. Are S-type symbiotics synchronized?★

Rotational velocities of the giants in symbiotic stars - II. Are S-type symbiotics synchronized?★

On the profiles and the polarization of Raman-scattered emission lines in symbiotic stars -- II. Numerical simulations

Wind asymmetry imprint in the UV light curves of the symbiotic binary SY Mus

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