Stuart Sim

• Position:

  SkyMapper Fellow

• The title of your research proposal:

  Modelling the spectra and light curves of supernovae

• A brief description of your research aims:

  I use a Monte Carlo radiative transfer (written by myself and Markus Kromer, MPA) to compute synthetic spectra and light curves for models of supernova explosions. By comparison with data, these synthetic spectra allow us to constrain both the explosion physics and the nature of the supernova progenitor systems. To date the code has mostly been applied to multi-dimensional models of Type Ia supernova - at Stromlo I will keep working on the modelling of Type Ias but also plan to extend the work to include Type Ib/c supernovae, including GRB supernovae (the physics of Ib/c supernovae is very similar to that of Ias). This work will interface with those working at Stromlo on observations of supernovae, particularly those involved with the transient search in the SkyMapper project.

• A brief description of the nature of the computations to be performed (resources required, interactive/batch job, i/o requirements, single processor/parallel jobs, scalability):

  The computations (Monte Carlo radiative transfer code) would all be performed in a batch mode with parallel processors. The code has already been extensively tested and used on the machines at MPA and scales very well up to several thousand processors - so it will perform very well on a machine with a moderate numbers of processors like Coala. The code has a hybrid MPI-OPENMP parallelisation so that it can run on systems with either (or both) in operation. Coala does not have enough processors for me to undertake full multi-dimensional simulations - for these I will apply for time via the ANU partner share on the big machine. However, Coala will be ideal for doing code development tests (I plan to add several new capabilities to the code in the near future - polarization and late-phase nebular spectra) and should also be adequate for running 1D models (which will form the initial phase of work on the modelling of SN Ib/c). I would expect that a serious test calculation might use around 32 or 64 processors for anywhere from a few hours up to one day. A full production-level 1D calculation (with all physics switched on) would use up to 64 processors for a few days. [The code can be restarted from any state so, although production level simualtions will require fairly long integrated run times, they do not require that resources be allocated continuously for a very long period.]

• Any additional information:

  I also have a very similar Monte Carlo radiative transfer code with which I work on the modelling of X-ray spectra (this time for the study of AGN). Although I will initially be mainly focused on getting my supernova code operational here, I will later want to continue to work with the X-ray code. Those simulations are less demanding that the supernova calculations but scale equally well - that code is MPI parallel only. So, in due course, I would also like to be allowed to use Coala for that project.