POSSIS: predicting spectra, light curves and polarization for multi-dimensional models of supernovae and kilonovae. (arXiv:1906.04205v1 [astro-ph.HE])

<a href="http://arxiv.org/find/astro-ph/1/au:+Bulla_M/0/1/0/all/0/1">Mattia Bulla</a>

We present POSSIS, a time-dependent three-dimensional Monte Carlo code for

modelling radiation transport in supernovae and kilonovae. The code

incorporates wavelength- and time-dependent opacities and predicts

viewing-angle dependent spectra, light curves and polarization for both

idealized and hydrodynamical explosion models. We apply the code to a kilonova

model with two distinct ejecta components, one including lanthanide elements

with relatively high opacities and the other devoid of lanthanides and

characterized by lower opacities. We find that a model with total ejecta mass

$M_mathrm{ej}=0.04,M_odot$ and half-opening angle of the lanthanide-rich

component $Phi=30^circ$ provides a good match to GW 170817 / AT 2017gfo for

orientations near the polar axis (i.e. for a system viewed close to face-on).

We then show how crucial is the use of self-consistent multi-dimensional models

in place of combining one-dimensional models to infer important parameters as

the ejecta masses. We finally explore the impact of $M_mathrm{ej}$ and $Phi$

on the synthetic observables and highlight how the relatively fast computation

times of POSSIS make it well-suited to perform parameter-space studies and

extract key properties of supernovae and kilonovae. Spectra calculated with

POSSIS in this and future studies will be made publicly available.

We present POSSIS, a time-dependent three-dimensional Monte Carlo code for

modelling radiation transport in supernovae and kilonovae. The code

incorporates wavelength- and time-dependent opacities and predicts

viewing-angle dependent spectra, light curves and polarization for both

idealized and hydrodynamical explosion models. We apply the code to a kilonova

model with two distinct ejecta components, one including lanthanide elements

with relatively high opacities and the other devoid of lanthanides and

characterized by lower opacities. We find that a model with total ejecta mass

$M_mathrm{ej}=0.04,M_odot$ and half-opening angle of the lanthanide-rich

component $Phi=30^circ$ provides a good match to GW 170817 / AT 2017gfo for

orientations near the polar axis (i.e. for a system viewed close to face-on).

We then show how crucial is the use of self-consistent multi-dimensional models

in place of combining one-dimensional models to infer important parameters as

the ejecta masses. We finally explore the impact of $M_mathrm{ej}$ and $Phi$

on the synthetic observables and highlight how the relatively fast computation

times of POSSIS make it well-suited to perform parameter-space studies and

extract key properties of supernovae and kilonovae. Spectra calculated with

POSSIS in this and future studies will be made publicly available.

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