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Wareing, Shân; Funnell, Peter; Boullier, Brian; Dalgleish, Heather; Morss, Kate; McAleese, Ray; Barker, Philip

doi:10.1080/0968776980060308

Cited by 4 publications

(8 citation statements)

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“…They proposed that its AGB wind has been stopped by the surrounding ISM and the swept-up 'wall' is now expanding at the local sound speed. Simulations by Villaver, Garcia-Segura & Manchado (2003) and Wareing et al (2006) confirmed the viability of this mechanism. It is likely that both mechanisms occur, but whether the external mechanism of an ISM wall or the internal mechanism of long-term mass-loss variations is the dominant cause of detached shells is not known.…”

Section: Introductionmentioning

confidence: 62%

“…The simulation is performed in the frame of reference of the star and the motion through the ISM is like that of an oncoming wind -hence our 'two-wind' model. Further details of the model are explained in Wareing et al (2006). We model a period of 5.5 × 10 4 yr on the AGB and have used a simulation grid of 200 3 cubic cells (cell size of 4 × 10 −3 pc) producing a grid of 0.8 pc in each direction.…”

Section: S I M U L At I O N Smentioning

confidence: 99%

“…We set the AGB wind parameters of the model with a mass-loss rate of 3 × 10 −7 M yr −1 and a velocity of 10 km s −1 . The temperature of the wind is set at 10 4 K, which is the lowest value for which the cooling function is defined (Wareing 2005). The real temperature will be considerably less than this, and indeed the temperature of the undisturbed AGB wind in the simulation is of the order of a few tens of K. Our simulations do not model dust physics or radiation transport.…”

Section: S I M U L At I O N Smentioning

confidence: 99%

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Detached shells as tracers of asymptotic giant branch–interstellar medium bow shocks

Wareing

Zijlstra

Speck

et al. 2006

Monthly Notices of the Royal Astronomical Society: Letters

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New Spitzer imaging observations have revealed the structure around the Mira variable star R Hya to be a one‐sided parabolic arc 100 arcsec to the west, stretching from north to south. We successfully model R Hya and its surroundings in terms of an interaction of the stellar wind from an asymptotic giant branch (AGB) star with the interstellar medium (ISM) the star moves through. Our three‐dimensional hydrodynamic simulation reproduces the structure as a bow shock into the oncoming ISM. We propose this as another explanation of detached shells around such stars, which should be considered alongside current theories of internal origin. The simulation predicts the existence of a tail of ram‐pressure‐stripped AGB material stretching downstream. Indications for such a tail behind R Hya are seen in IRAS maps.

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Section: Introductionmentioning

confidence: 62%

Section: S I M U L At I O N Smentioning

confidence: 99%

Section: S I M U L At I O N Smentioning

confidence: 99%

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Detached shells as tracers of asymptotic giant branch–interstellar medium bow shocks

Wareing

Zijlstra

Speck

et al. 2006

Monthly Notices of the Royal Astronomical Society: Letters

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“…The numerical scheme, CUBEMPI, used in our simulations to solve the hydrodynamics equations employs a second-order Godunov solution due to Falle (1991). In recent years, variants of CUBEMPI have been used to shed light on nova explosions (Lloyd, O'Brien & Bode 1997;Porter, O'Brien & Bode 1998), extragalactic jetcloud interactions (Higgins, O'Brien & Dunlop 1999) and most recently PNe (Wareing et al 2006a;Mitchell 2007). The version of the scheme used here is posed in three-dimensional cartesian coordinates, fully parallel and includes the effect of radiative cooling due to the cooling curves of Raymond, Cox & Smith (1976) above 10 4 K as the cooling curves extend no farther.…”

Section: T H E H Y D Ro Dy Na M I C S C H E M E a N D T R I P L E -W mentioning

confidence: 99%

“…In order to investigate the interaction further, we have developed a 'triple-wind' model including an initial slow AGB wind, a subsequent fast post-AGB wind, and a third continuous wind reflecting the movement through the ISM. Employing a parallel three-dimensional hydrodynamic scheme developed by Wareing (2005), we have understood the formation of the extreme PN Sh 2-188 (Wareing et al 2006a) and the structure around the AGB star R Hya (Wareing et al 2006b).…”

Section: Introductionmentioning

confidence: 99%

The interaction of planetary nebulae and their asymptotic giant branch progenitors with the interstellar medium

Wareing¹,

Zijlstra²,

O’Brien³

2007

Monthly Notices of the Royal Astronomical Society

111

132

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Interaction with the interstellar medium (ISM) cannot be ignored in understanding planetary nebula (PN) evolution and shaping. In an effort to understand the range of shapes observed in the outer envelopes of PNe, we have run a comprehensive set of three‐dimensional hydrodynamic simulations, from the beginning of the asymptotic giant branch (AGB) superwind phase until the end of the post‐AGB/PN phase. A ‘triple‐wind’ model is used, including a slow AGB wind, fast post‐AGB wind and third wind reflecting the linear movement through the ISM. A wide range of stellar velocities, mass‐loss rates and ISM densities have been considered. We find that ISM interaction strongly affects outer PN structures, with the dominant shaping occurring during the AGB phase. The simulations predict four stages of PN–ISM interaction whereby (i) the PN is initially unaffected, (ii) then limb‐brightened in the direction of motion, (iii) then distorted with the star moving away from the geometric centre, and (iv) finally so distorted that the object is no longer recognizable as a PN and may not be classed as such. Parsec‐size shells around PNe are predicted to be common. The structure and brightness of ancient PNe are largely determined by the ISM interaction, caused by rebrightening during the second stage; this effect may address the current discrepancies in Galactic PN abundance. The majority of PNe will have tail structures. Evidence for strong interaction is found for all known PNe in globular clusters.

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Fundamentals and applications of self-assembled plasmonic nanoparticles at interfaces

2016

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This tutorial review will introduce and explore fundamental and applied aspects of electrolytic interfaces incorporating nanoscale building blocks for use in novel applications such as sensors and tunable optics. In order to do this, it is important to understand the principles behind even the simplest of immiscible interfaces such as those of the liquid|liquid and solid|liquid. Qualitatively, the picture is simple however the complexity is easily compounded by the addition of electrolyte, and further compounded by the addition of more complex entities such as nanoparticles. Nevertheless combining all these components surprisingly results in an elegant solution, where the nanoparticles have the ability to self-assemble at the interface with a high level of control. Importantly, this opens up the door to the development of new types of materials with a range of applications which have only recently been exploited. Initially we begin with a description of the fundamentals related to liquid|liquid and solid|liquid interfaces both with and without electrolyte. The discussion then shifts to a description of biasing the interface by the application of an electric field. This is followed by an exploration of nanoparticle assembly and disassembly at the interface by controlling parameters such as ligand composition, charge, pH, and electric field. Finally a description of the state-of-the-art is given in terms of current applications and possible future directions. It is perhaps fair to say that these new frontiers have caused great excitement within the sensing community not only due to the simplicity of the technique but also due to the unprecedented levels of sensitivity and control.

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Reviews

Cited by 4 publications

References 0 publications

Detached shells as tracers of asymptotic giant branch–interstellar medium bow shocks

Detached shells as tracers of asymptotic giant branch–interstellar medium bow shocks

The interaction of planetary nebulae and their asymptotic giant branch progenitors with the interstellar medium

Fundamentals and applications of self-assembled plasmonic nanoparticles at interfaces

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