| 1. |
- Chomiuk, L., et al.
(författare)
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Binary orbits as the driver of gamma-ray emission and mass ejection in classical novae
- 2014
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 514:7522, s. 339-
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Tidskriftsartikel (refereegranskat)abstract
- Classical novae are the most common astrophysical thermonuclear explosions, occurring on the surfaces of white dwarf stars accreting gas from companions in binary star systems(1). Novae typically expel about 10(-4) solar masses of material at velocities exceeding 1,000 kilometres per second. However, the mechanism of mass ejection in novae is poorly understood, and could be dominated by the impulsive flash of thermonuclear energy(2), prolonged optically thick winds(3) or binary interaction with the nova envelope(4). Classical novae are now routinely detected at gigaelectronvolt gamma-ray wavelengths(5), suggesting that relativistic particles are accelerated by strong shocks in the ejecta. Here we report high-resolution radio imaging of the gamma-ray-emitting nova V959 Mon. We find that its ejecta were shaped by the motion of the binary system: some gas was expelled rapidly along the poles as a wind from the white dwarf, while denser material drifted out along the equatorial plane, propelled by orbital motion(6,7). At the interface between the equatorial and polar regions, we observe synchrotron emission indicative of shocks and relativistic particle acceleration, thereby pinpointing the location of gamma-ray production. Binary shaping of the nova ejecta and associated internal shocks are expected to be widespread among novae(8), explaining why many novae are gamma-ray emitters(5).
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| 2. |
- Overington, A. R., et al.
(författare)
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Flavour release and perception in cheese bases
- 2010
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Ingår i: Australian Journal of Dairy Technology. - 0004-9433. ; 65:3, s. 162-164
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Tidskriftsartikel (refereegranskat)abstract
- To be able to deliver customised flavours from cheese matrices that have different textures and compositions, it is important to understand how the cheese matrix affects the perception of flavour. It is known that perceived flavours depend not only on the combination of tastants and aroma compounds in a food, but also on the way in which those flavour compounds are released from the food matrix. In addition, flavour perception can be influenced by cross-modal sensory interactions between taste, aroma and texture. In a collaborative research project between Fonterra Research Centre, The University of Otago in New Zealand and CSIRO in Australia, we are evaluating flavour release and cross-modal sensory interactions in a cheese base. Our aim is to understand how perceived flavour is affected by the texture and composition of the cheese and by the combination of tastants and aroma compounds making up the flavour. Sets of cheese bases were created with similar textures but different compositions, and similar compositions but different textures. Flavour compounds were added, and the equilibrium flavour release was studied using proton transfer reaction mass spectrometry, and related to flavour perception using descriptive sensory analysis.
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