PROJECT

Proposing a new mechanism of dust formation around carbon-rich stars through atomistic simulations of the aggregation of polyaromatic hydrocarbons

Using computer simulations to describe a mechanism for cosmic dust grain seed formation around carbon-rich stars

 

Observations from radio telescopes have determined that an envelope of dust surrounds certain stars. These particular stars emit more carbon and less oxygen than most other stars. Other work has accumulated evidence that polycyclic aromatic hydrocarbons (PAHs) exist in the interstellar medium. Since from terrestrial investigations, it is known that flames produce PAHs, a hypothesis has grown that around these carbon rich stars polycyclic aromatic hydrocarbons are synthesized in a manner similar to that occurring in flames.

As these molecules become larger the forces of attraction between the large molecules become sufficient to allow molecules to aggregate together in the prevailing temperature of 1000 K or a little less. In this project you will study the clustering of PAHs using molecular dynamics simulations (MD) and perform highly accurate ab initio simulations to investigate the interaction energy of these clusters. You will be using MD simulations to provide evidence of a mechanism of the aggregation to form heterogeneous clusters, which are made up of different polycyclic aromatic hydrocarbons. You will also be investigating the driving force of this aggregation mechanism by using ab initio simulations. 

The results of this project will form the basis of a model that will provide evidence of how dust forms in outer space, which then go on to form larger celestial objects.

Project goals:

  • Determine the temperatures required for aggregation of polyaromatic hydrocarbons
  • Understand the differences in the properties of aggregation between homogenous and heterogenous mixtures
  • Understand the structure and stability of the particles
As part of this project the successful PhD applicant will:
  • Perform a series of large scale molecular dynamic simulations of polyaromatic hydrocarbons
  • Perform a series of highly accurate ab initio calculations to determine the interaction energies of dimers and trimers
  • Analyse the structures of these particles and understand the stability




Suggested readings

 


Research team leader: Dr Dino Spagnoli

I am a computational chemist and senior lecturer in the School of Molecular Sciences at UWA. My research is focused on the application of computer simulations to investigate the aggregation of polyaromatic hydrocarbons which have astrochemical and environmental implications.

 


Collaborations

  External Collaborators:
    • Dr Irene Suarez Martinez, Curtin University
    • Dr Dahbia Talbi, Université Montpellier

     

Handshake


How to Apply 

Check criteria
  • To be accepted into the Doctor of Philosophy, an applicant must demonstrate they have sufficient background experience in independent supervised research to successfully complete, and provide evidence of English language proficiency
  • Requirements specific to this project:
    • A bachelor’s degree with honours (or equivalent) in chemistry, physics or related disciplines.
    • Experience with atomistic simulation software and working with a Linux operating system is desirable but not essential.
Submit enquiry to research team leader 
  • Contact the research team leader by submitting an Expression of Interest form via the button below
  • After you have discussed your project with the research team leader, contact hdr-science@uwa.edu.au to proceed with your application

Scholarships