We present synthetic spectra and SEDs computed along evolutionary tracks at Z=1/5 Zsun and Z=1/30 Zsun, for masses between 15 and 150 Msun. We predict that the most massive stars all start their evolution as O2 dwarfs at sub-solar metallicities. The fraction of lifetime spent in the O2V phase increases at lower metallicity. The distribution of dwarfs and giants we predict in the SMC accurately reproduces the observations. Supergiants appear at slightly higher effective temperatures than we predict. More massive stars enter the giant and supergiant phases closer to the ZAMS, but not as close as for solar metallicity. This is due to the reduced stellar winds at lower metallicity. Our models with masses higher than ~60 Msun should appear as O and B stars, whereas these objects are not observed, confirming a trend reported in the recent literature. At Z=1/30 Zsun, dwarfs cover a wider fraction of the MS and giants and supergiants appear at lower effective temperatures than at Z=1/5 Zsun. The UV spectra of these low-metallicity stars have only weak P-Cygni profiles. HeII 1640 sometimes shows a net emission in the most massive models, with an equivalent width reaching ~1.2 A. For both sets of metallicities, we provide synthetic spectroscopy in the wavelength range 4500-8000 A. This range will be covered by the instruments HARMONI and MOSAICS on the ELT and will be relevant to identify hot massive stars in Local Group galaxies with low extinction. We suggest the use of the ratio of HeI 7065 to HeII 5412 as a diagnostic for spectral type. We show that this ratio does not depend on metallicity. Finally, we discuss the ionizing fluxes of our models. The relation between the hydrogen ionizing flux per unit area versus effective temperature depends only weakly on metallicity. The ratios of HeI and HeII to H ionizing fluxes both depend on metallicity, although in a slightly different way.

We present recent progress on quantum trajectories method for one dimensional resonant reactive scattering processes.

Cumulative reaction probability plays a central role in the calculation of reaction rate constant of any bimolecular chemical reaction of interest. In order to give meaningful results, these calculations should be performed for chemical systems with a large number of degrees of freedom leadingto expensive and often infeasible simulations. In this work, a new computational scheme is proposed to allow high dimensional quantum reactive simulations. This scheme is based on the Green’s function operator technics combined to absorbing boundary conditions, a powerful approach introduced by W.H. Miller, T. Seideman and U. Manthe many years ago [1,2]. The new implementation takes benefit that the initial quantum reactive scattering problem can be cast into an eigenvalue problem [2] and uses the high efficiency and accuracy of Smolyak algorithm [3] to build very compact basis for eigenvalue problems [4]. Using this new computational framework, it is now possible to perform quantum dynamics simulations for multidimensional systems pushing away the curse of dimensionality problem. Some preliminary results will be presented [5] using this new powerful scheme

In Bohmian quantum mechanics, both Schrödinger's wavefunction and an ensemble of quantum trajectories are propagated together to describe the evolution of a given system. Said trajectories are driven by anadditional, fully quantum potential deduced from the "pilot" wave function. Displacement of the trajectory ensemble symmetrically dictates the evolution of the wave function. However a recent reformulation allows the exclusive use of the trajectory ensemble to modelize the scattering process. The resulting equations of motion for the trajectories can be put in an Hamiltonian form, with coupled first order ODEs describing exactly the behaviour of a 1D time-independent process. In this case, propagation of a single trajectory is sucient to completely characterize the system. This ecient procedure ( great stability and accuracy ) was applied to scattering processes through simple potential barrier model and more recently in a quantum capture model of ultra-cold chemical reaction. I will highlight the virtues of this approach when applied to scattering through multiple potential barriers. In this more complex situation often encountered in chemistry, coupling with metastable states breaks themonotonicity of the cumulated reaction probability prole through the presence of resonance peaks. Strong interference patterns are observed inbetween the barrier and necessitate the use of an adaptative ODE solving procedure. Numerical simulations will be presented both on system models and on a 1D-reaction path hamiltonian model of ketene izomerisation for which conventional quantum mechanical calculations (using grid methods and absorbing boundary conditions) are available. I will also present how Hamiltonianform allows for a straightforward extension of the one-dimensional quantum formalism to multidimensional processes through the use of hybrid quantum-classical trajectories. The efficiency of this dual-level theorywill be illustrated on the ketene isomerization process.

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Until recently, camera networks designed for monitoring fireballs worldwide were not fully automated, implying that in case of a meteorite fall, the recovery campaign was rarely immediate. This was an important limiting factor as the most fragile - hence precious - meteorites must be recovered rapidly to avoid their alteration. Aims: The Fireball Recovery and InterPlanetary Observation Network (FRIPON) scientific project was designed to overcome this limitation. This network comprises a fully automated camera and radio network deployed over a significant fraction of western Europe and a small fraction of Canada. As of today, it consists of 150 cameras and 25 European radio receivers and covers an area of about 1.5 million square kilometers.