Dr Ahmad Ali
Postdoctoral Research Fellow
I study star formation and stellar feedback, particularly for massive stars (spectral type O, > 20 solar masses). My research focuses on radiative processes such as photoionization and radiation pressure and (1) how these feedback mechanisms disperse gas from clusters in giant molecular clouds; (2) how star formation rates and efficiencies are modified via heating, dispersal, or collect-and-collapse of gas reservoirs; (3) how the radiative processes interplay with other mechanisms such as stellar winds and supernovae; (4) how the intense radiation fields inside H II regions affect structures such as protoplanetary discs and gas globules via photoevaporation.
I carry out numerical simulations to investigate these processes using TORUS, the code developed in Exeter by Prof. Tim Harries and collaborators including myself. TORUS uses a Monte Carlo radiative transfer scheme coupled with hydrodynamics on a 3D grid. This calculates in detail the photoionization, thermal, and radiative equilibria for multiple atomic species and dust grains. TORUS also calculates synthetic observations of line and continuum emission from gas and dust directly from the radiation-hydrodynamics models.
Such models are computationally demanding, requiring the efficient use of High Performance Computing machines (e.g. Isca in Exeter, and national DiRAC facilities). As such, I also work on improving the parallelism of TORUS, in particular with MPI.
Employment and education
- Oct 2019 to present -- Postdoctoral Research Fellow (University of Exeter) with Prof. Clare Dobbs in ERC project ICYBOB
- Jul 2018 to Sep 2019 -- Postdoctoral Research Associate (University of Exeter) with Prof. Tim Harries
- 2014 to 2018 -- PhD Physics (University of Exeter) supervised by Prof. Tim Harries on formation and feedback processes of massive stars
- 2010 to 2014 -- MSci Astrophysics (University College London)
- 2018/19 -- Stage 2 maths problems senior tutor
- 2015 to 2018 -- Stage 2 maths problems tutor
- 2015 to 2018 -- Stage 1 physics problems tutor
- 2014 to 2018 -- Stage 2 physics lab demonstrator
- 2017 -- Stage 1 IT skills demonstrator