A5102902376- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- Evolution and Paleontology Studies
- Paleontology and Stratigraphy of Fossils
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Spaceflight effects on biology
- Planetary Science and Exploration
- Molecular Spectroscopy and Structure
- Atmospheric Ozone and Climate
- Space Science and Extraterrestrial Life
- Material Science and Thermodynamics
University of Leeds
2021
University of Central Lancashire
2018
University of Leicester
2012-2015
Pontificia Universidad Católica de Chile
2014-2015
University of Bristol
2011
The finding of residual gas in the large central cavity HD142527 disk motivates questions on origin its non-Keplerian kinematics, and possible connections with planet formation. We aim to understand physical structure that underlies intra-cavity gaseous flows, guided by new molecular-line data CO(6-5) unprecedented angular resolutions. Given warped inferred from identification scattered-light shadows cast outer disk, kinematics are consistent, first order, axisymmetric accretion onto inner...
The identification of ongoing planet formation requires the finest angular resolutions and deepest sensitivities in observations inspired by state-of-the-art numerical simulations. Hydrodynamic simulations planet–disk interactions predict circumplanetary disks (CPDs) around accreting planetary cores. These CPDs have eluded unequivocal detection—their predictions CPD tracers. In this work, we aim to assess observability embedded with Atacama Large Millimeter/submillimeter Array (ALMA) as...
We present high-resolution 3D simulations of the planet–disc interaction using smoothed particle hydrodynamics to investigate possibility driving eccentricity growth by this mechanism. For models with a given disc viscosity (α = 0.01), we find that for small planet masses (a few Jupiter masses) and canonical surface densities, no significant is seen over duration our simulations. This contrasts limiting case large mass (over 20 MJup) extremely high where in agreement previously published...
We present the results of smoothed particle hydrodynamics (SPH) simulations disc around young, eccentric stellar binary HD 104237. find that clears out a large cavity in disc, driving significant eccentricity at edge. This then precesses rate |$\dot{\varpi } = 0{^{\circ}_{.}} 48T_{\mathrm{b}}^{-1}$|, which for 104237 corresponds to precession period 40 years. accretion pattern into and on changes with this precession, resulting periodic variability driven purely by physical parameters its...
The recent discovery of a number circumbinary planets lends new tool to astrophysicists seeking understand how and where planet formation takes place. Of the increasingly numerous systems, Kepler-16 is arguably most dynamically interesting: it consists on an almost perfectly circular orbit (e = 0.0069) around moderately eccentric binary 0.16). We present high-resolution 3D smoothed-particle hydrodynamics simulations analogue embedded in disc, show that planet's eccentricity damped by its...
We present the results of high-resolution numerical simulations gas clouds falling on to binary supermassive black holes form circumbinary accretion discs, with both prograde and retrograde cloud orbits. explore a range masses cooling rates. find that for low-mass discs cool fast enough fragment, are significantly shorter lived than similar orbiting respect binary. For fragmenting all masses, we also fragment across narrower radial region. If is slow disc enters self-regulating...
Radiative transfer is an important component of hydrodynamic simulations as it determines the thermal properties a physical system. It especially in cases where heating and cooling regulate significant processes, such collapse molecular clouds, development gravitational instabilities protostellar discs, disc-planet interactions, planet migration. We compare two approximate radiative methods which indirectly estimate optical depths within using different metrics: (i) potential density gas...
I present the results of 1D models circumplanetary discs around planets on eccentric orbits. use a classical viscous heating model to calculate emission fluxes at wavelengths targeted by NIRCam instrument JWST, and compare variability this signal with published sensitivity specifications. This is theoretically detectable JWST for sufficiently disc ($\alpha \sim 10^{-2}$) planet ($e 0.1-0.2$) if accretes material from its parent rate $\dot{M} \gtrsim 10^{-7}\,...
I present the results of semi-analytic calculations migrating planets in young, outbursting circumstellar discs. Formed far out disc via gravitational fragmentation early on its lifetime, these typically migrate at very slow rates and are therefore mostly expected to remain large radii (such as is case HR 8799). show that changes structure during FU Orionis outbursts affect planet’s ability maintain a gap can allow massive giant semimajor axis reduce by almost 5 per cent single outburst...
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<p>Records of sulfur cycling during mass extinction events increasingly show that they are associated with rapid shifts in the isotope composition seawater indicative low concentrations ocean sulfate [1-4]. These also often spread anoxic conditions marine realm. We propose a feedback mechanism whereby production methane sediments increases proportion to decreasing and consumes bottom water oxygen, thus acting as positive on waters. This can be further amplified via increased...