Sim, S. A., Kromer, M., Roepke, F. K., Sorokina, E. I., Blinnikov, S. I., Kasen, D., ...
The theory of radiative transfer provides the link between the physical conditions in an astrophysical object and the observable radiation which it emits. Thus accurately modelling radiative transfer...
Late-time supernova light curves: The effect of internal conversion and Auger electrons (2009)
Seitenzahl, I. R., Taubenberger, S., Sim, S. A.
Energy release from radioactive decays contributes significantly to supernova light curves. Previous works, which considered the energy deposited by gamma-rays and positrons produced by 56Ni, 56Co,...
Nebular emission-line profiles of Type Ib/c supernovae – probing the ejecta asphericity (2009)
Taubenberger, S., Valenti, S., Benetti, S., Cappellaro, E., Della Valle, M., Elias-Rosa, N., ...
In order to assess qualitatively the ejecta geometry of stripped-envelope core-collapse supernovae (SNe), we investigate 98 late-time spectra of 39 objects, many of them previously unpublished. We...
Time-dependent 3D spectrum synthesis for type Ia supernovae (2009)
A Monte Carlo code (ARTIS) for modelling time-dependent three-dimensional spectral synthesis in chemically inhomogeneous models of Type Ia supernova ejecta is presented. Following the propagation of...
3D non-LTE spectrum synthesis for Type Ia supernovae (2009)
Kromer, M., Sim, S. A., Hillebrandt, W.
Despite the importance of Type Ia supernovae as standard candles for cosmology and to the chemical evolution of the Universe, we still have no consistent picture of the nature of these events. Much...
Nebular emission-line profiles of Type Ib/c Supernovae - probing the ejecta asphericity (2009)
Taubenberger, S., Valenti, S., Benetti, S., Cappellaro, E., Della Valle, M., Elias-Rosa, N., ...
In order to assess qualitatively the ejecta geometry of stripped-envelope core-collapse supernovae, we investigate 98 late-time spectra of 39 objects, many of them previously unpublished. We perform...
Nebular emission-line profiles of type Ib/c supernovae – probing the ejecta asphericity (2009)
Taubenberger, S., Valenti, S., Benetti, S., Cappellaro, E., Della Valle, M., Elias-Rosa, N., ...
Multi-dimensional modelling of X-ray spectra for AGN accretion-disk outflows (2008)
Sim, S. A., Long, K. S., Miller, L., Turner, T. J.
We use a multi-dimensional Monte Carlo code to compute X-ray spectra for a variety of active galactic nucleus (AGN) disk-wind outflow geometries. We focus on the formation of blue-shifted absorption...
On the gamma-ray emission of Type Ia Supernovae (2007)
A multi-dimension, time-dependent Monte Carlo code is used to compute sample gamma-ray spectra to explore whether unambiguous constraints could be obtained from gamma-ray observations of Type Ia...
Light curves for off-centre ignition models of type Ia supernovae (2007)
Sim, S. A., Sauer, D. N., Röpke, F. K., Hillebrandt, W.
Motivated by recent models involving off-centre ignition of type Ia supernova explosions, we undertake three-dimensional time-dependent radiation transport simulations to investigate the range of...
Hillebrandt, W., Sim, S. A., Röpke, F. K.
The recent discovery of a very bright type Ia supernova, SNLS-03D3bb ($\equiv$ SN 2003fg), in the Supernova Legacy Survey (SNLS) has raised the question of whether super-Chandrasekhar-mass white...
Multi-dimensional simulations of radiative transfer in Type Ia supernovae (2006)
A three-dimensional Monte Carlo code for modelling radiation transport in Type Ia supernovae is described. In addition to tracking Monte Carlo quanta to follow the emission, scattering and deposition...
2-D Monte Carlo simulations of H I line formation in massive YSO disk winds (2005)
Sim, S. A., Drew, J. E., Long, K. S.
Massive young stellar objects (YSOs) are powerful infrared H I line emitters. It has been suggested that these lines form in a outflow from a disk surrounding the YSO. Here, new two-dimensional Monte...
Modelling the chromosphere and transition region of Epsilon Eri (K2 V) (2005)
Measurements of ultraviolet line fluxes from Space Telescope Imaging Spectrograph and Far-Ultraviolet Spectroscopic Explorer spectra of the K2-dwarf Epsilon Eri are reported. These are used to...
Modelling the X-ray spectra of high velocity outflows from quasars (2004)
High velocity outflows from supermassive black holes have been invoked to explain the recent identification of strong absorption features in the hard X-ray spectra of several quasars. Here, Monte...
Mass-loss rates for hot luminous stars: the influence of line branching (2004)
The effect of photon frequency redistribution by line branching on mass-loss rates for hot luminous stars is investigated. Monte Carlo simulations are carried out for a range of OB-star models which...
On the filling factor of emitting material in the upper atmosphere of Epsilon Eri (K2 V) (2003)
The emission measure distribution in the upper transition region and corona of Epsilon Eri is derived from observed emission line fluxes. Theoretical emission measure distributions are calculated...
A study of velocity fields in the transition region of Epsilon Eri (K2 V) (2003)
Analyses of the widths and shifts of optically thin emission lines in the ultraviolet spectrum of the active dwarf Epsilon Eri (K2 V) are presented. The spectra were obtained using the Space...
Jordan, C., McMurry, A. D., Sim, S. A., Arulvel, M.
We report observations of the dwarf star Epsilon Eri (K2 V) made with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST). The high sensitivity of the STIS instrument...