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2D condensation model for the inner Solar Nebula: an enstatite-rich environment

Infrared observations provide the dust composition in the protoplanetary discs surface layers, but cannot probe the dust chemistry in the mid-plane, where planet formation occurs. Meteorites show ... to be considered if we are to understand the global chemistry in discs. 1D radial condensation sequences can only simulate one disc layer at a time and cannot describe the global chemistry or the

ISM chemistry in metal-rich environments: molecular tracers of metallicity

In this paper we use observations of molecular tracers in metal-rich and α-enhanced galaxies to study the effect of abundance changes on molecular chemistry. We selected a sample of metal-rich spiral ... neighbourhood (Shields & Ferland 1994; Maeda et al. 2002) . In the next decade, as the power of millimetre wavelength facilities continues to grow we will be able to investigate in greater detail the chemistry

Chemistry in a gravitationally unstable protoplanetary disc

when self-gravity is important. In this case, spiral waves and shocks cause temperature and density variations that affect the chemistry. We have adopted a dynamical model of a solar-mass star surrounded ... -gravitating disc, similar to those that may be found around Class 0 and early Class I protostars, in a study of disc chemistry. We find that for each of a number of species, e.g. H2O, adsorption and desorption

Chemistry in cosmic ray dominated regions

rays. Historically, the cosmic ray ionization rate in Galactic diffuse and molecular clouds has normally been determined by treating it as a free parameter and matching the predicted chemistry to that ... observed (e.g. Black & Dalgarno 1977; Hartquist, Doyle & Dalgarno 1978a; Hartquist, Black & Dalgarno 1978b). Here, it is necessary to reverse that procedure and to compute the variation of the chemistry as

An analytical model of radiation-induced Charge Transfer Inefficiency for CCD detectors

in order to characterize the CTI effects. Monte Carlo (e.g. Prod’homme et al. 2011) and analytical models have also been developed which go some way to reproducing Gaia radiation test data. However ... present our conclusions. 2 B AC K G R O U N D T O T H E M O D E L The objective is to derive an analytical CDM that takes into account recent illumination and charge injection history5 and is based upon

Carbon chemistry in Galactic bulge planetary nebulae

Galactic bulge planetary nebulae show evidence of mixed chemistry with emission from both silicate dust and polycyclic aromatic hydrocarbons (PAHs). This mixed chemistry is unlikely to be related to ... Telescope (HST ) images and Ultraviolet and Visual Echelle Spectrograph (UVES) spectra show that the mixed chemistry is not related to the presence of emission-line stars, as it is in the Galactic disc

High-order analytical solutions around triangular libration points in the circular restricted three-body problem

High-order analytical solutions around the triangular libration points in the circular restricted three-body problem (CRTBP) are constructed in this paper. It is known that the linearized equations ... all be parametrized. To check the validity of series expansions, numerically integrated orbits with the same initial states as analytical orbits are computed, and the practical convergence of analytical

Yields of AGB and SAGB models with chemistry of low- and high-metallicity globular clusters

We present yields from stars of mass in the range M⊙ ≤ M ≤ 8 M⊙ of metallicities Z = 3 × 10−4 and 8 × 10−3, thus encompassing the chemistry of low- and high-Z globular clusters. The yields are based ... third dredge-up, thus ejecting into their surroundings gas enriched in carbon and nitrogen. Conversely, hot bottom burning is mainly responsible for the modification of the surface chemistry of more

Analytical maximum likelihood estimation of stellar magnetic fields

) . Here we present analytical expressions for inferring the magnetic field vector from the observed Stokes profiles induced by the Zeeman effect in the weak-field approximation. The weak-field ... approximation is broadly applied for the inference of solar and stellar magnetic fields from the observation of the Stokes profiles. It is an analytical solution to the radiative transfer equation whose main

Chemistry of dense clumps near moving Herbig–Haro objects

of the shock front, typically travelling at a few hundred km s1 through a molecular cloud. Raga & Williams (2000) investigated, using a simple chemistry, the effect of a moving field on the expected ... morphology of the emission but the full consequences on the chemistry of allowing the radiation source to move have not been explored. In this scenario, the HHO (the source of the radiation driving the

Warm non-equilibrium gas phase chemistry as a possible origin of high HDO/H2O ratios in hot and dense gases: application to inner protoplanetary discs

gas (T= 100–1000 K) by gas-phase photochemistry in the absence of grain surface chemistry. We derive analytical solutions, taking into account the major neutral–neutral reactions for gases at T > 100 K ... because of the difference in activation energy between deuteration enrichment and the back reactions. The analytical solutions were confirmed by the time-dependent chemical results in a 10−3 M disc around a

Analytical potential–density pairs for bars

An identity that relates multipolar solutions of the Einstein equations to Newtonian potentials of bars with linear densities proportional to Legendre polynomials is used to construct analytical

Analytical approximations to numerical solutions of theoretical emission measure distributions

. The scaling laws that exist between coronal parameters arise from the dimensions of the terms in the energy balance equation. Here, analytical approximations to numerical solutions for Emdt(Te) are ... ). It is shown that, for the energy balance and geometry adopted, the analytical values of the emission measure and electron pressure at To and Tc depend on only three parameters: the stellar surface

Approximations for modelling CO chemistry in giant molecular clouds: a comparison of approaches

We examine several different simplified approaches for modelling the chemistry of CO in 3D numerical simulations of turbulent molecular clouds. We compare the different models both by looking at the ... -scale chemistry is modelled. molecular processes - ISM; clouds - ISM; molecules - galaxies; ISM 1 I N T R O D U C T I O N Carbon monoxide (CO) is a key constituent of the gas making up the giant

Magnetic bubbles and magnetic towers – I. General properties and simple analytical models

to discuss some recent results of Braithwaite on MBEq formation by relaxation from an initial non-equilibrium state. We next present two families of exact analytical axisymmetric MBEqs with ... results established in Appendices A and B, we derive in particular integral relations involving various energies. Thus, we present explicit analytical solutions for both MBEqs and MTEqs, the one based on a

Analytical solution of a satellite orbit disturbed by atmospheric drag

In this paper, we derive the analytical solution of a satellite orbit disturbed by atmospheric drag. The disturbance force vector is first transformed and rotated to the orbital frame so that it can ... with respect to M , (ω, i) and t, respectively, to obtain the analytical solutions of satellite orbits disturbed by atmospheric drag. Some interesting conclusions are obtained theoretically. The

An analytical solution for Kepler's problem

In this paper, we present a framework which provides an analytical (i.e. infinitely differentiable) transformation between spatial coordinates and orbital elements for the solution of the ... use instead of M. Since is an integral of the motion, = M = n. Therefore for circular orbits 0 and equations (4) and (5) should be replaced by To obtain an analytical solution to the problem, i.e

BOOMERanG constraints on primordial non-Gaussianity from analytical Minkowski functionals

analytical formulae, derived by Hikage et al., which can be used to constrain the coupling parameter fNL without the need for non-Gaussian simulations. We find −770 < fNL < 500 at 95 per cent CL, significantly ... temperature fluctuation f T /T normalized by its standard deviation f 2 1/2. Following the formalism by Matsubara (2003) and Hikage et al. (2006), we can write the analytical formula for the kth MF of weakly

Spherically averaging ellipsoidal galaxy clusters in X-ray and Sunyaev–Zel’dovich studies – I. Analytical relations

–Zel’dovich (SZ) studies, though many of the results also apply to isotropic dispersion-supported stellar dynamical systems. Here we present analytical formulae for galaxy clusters described by a gravitational ... different biases owing to spherical averaging, which leads to an offset in the spherically averaged YSZ-YX relation. A potentially useful application of the analytical formulae presented is to assess the

KiDS-450: cosmological parameter constraints from tomographic weak gravitational lensing

independent techniques based on angular cross-correlations and the properties of the photometric redshift probability distributions. Our covariance matrix is determined using an analytical approach, verified ... . (2012) as this estimate can be used to directly populate numerical simulations to create an unweighted mock galaxy catalogue, and it is also used in the creation of the analytical covariance (Section 5.3