Benchmarks and models for time-dependent grey radiation transport with material temperature in binary stochastic media

2001 ◽  
Vol 70 (1) ◽  
pp. 115-128 ◽  
Author(s):  
D.S Miller ◽  
F Graziani ◽  
Garry Rodrigue
Keyword(s):  
Radiation Transport ◽  
Time Dependent ◽  
Stochastic Media ◽  
Material Temperature

scholarly journals Hydrodynamics of Accretion Columns

1987 ◽  
Vol 93 ◽  
pp. 591-594
Author(s):  
H. Herold ◽  
K. Wolf ◽  
H. Ruder
Keyword(s):  
Accretion Rate ◽  
Radiation Transport ◽  
Critical Value ◽  
Stationary Solutions ◽  
Time Dependent ◽  
Physical Parameters ◽  
High Luminosity ◽  
Accretion Flows ◽  
Accretion Rates ◽  
Parameter Ranges

AbstractA detailed understanding of how the infalling matter in accretion columns is decelerated is essential for the calculation of the emitted radiation. On neutron stars, the deceleration takes place mainly by the interaction of the plasma with radiation, at least for the high-luminosity sources. We report on our two-dimensional calculations of the hydrodynamic flow in such accretion columns. The radiation transport is treated in the diffusion approximation, and we are looking for a stationary solution for the velocity field. The dependence of the results on physical parameters, especially on the accretion rate is discussed. Due to the non-linearity of the problem it turns out that only in certain parameter ranges stationary solutions seem to exist. For accretion rates higher than a critical value there are no stationary accretion flows. This leads us to the conclusion that a time-dependent picture for the accretion is unavoidable.

scholarly journals possis: predicting spectra, light curves, and polarization for multidimensional models of supernovae and kilonovae

2019 ◽  
Vol 489 (4) ◽  
pp. 5037-5045 ◽  
Author(s):  
M Bulla
Keyword(s):  
Radiation Transport ◽  
Three Dimensional ◽  
Polar Axis ◽  
Light Curves ◽  
Time Dependent ◽  
Opening Angle ◽  
Monte Carlo Code ◽  
Lanthanide Elements ◽  
The Impact ◽  
Multidimensional Models

ABSTRACT 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 $M_\mathrm{ej}=0.04\, \mathrm{M}_\odot$ and half-opening angle of the lanthanide-rich component Φ = 30° 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 multidimensional models in place of combining one-dimensional models to infer important parameters, such as the ejecta masses. We finally explore the impact of Mej and Φ 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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