| Date | Place | Level | Subject | Qualification |
|---|---|---|---|---|
| 2002- | Monash University Melbourne Australia | PDRF | Observational Astrophysics | . |
| 2001-2002 | The Open University Milton Keynes UK | PDRA | Stellar Chemistry | . |
| 1998-2001 | Keele University | PhD | Astrophysics | . |
| 1995-98 | Keele University UK | BSc. (hons) | Astrophysics Chemistry | Joint Hons Class I |
| 1993-95 | Cadbury College Birmingham UK | A-Level | Chemistry| A | A A |
My astrophysics work has focussed around stellar spectroscopy, especially using Echelle spectrographs. My main studies so far have been my undergraduate final year project, "The composition of chemically peculiar star Nu Dra", and my PhD thesis, "Lithium in young open clusters and halo stars".
My current project is a detailled abundance analysis of halo stars, comparing those which are lithium poor against others which are "lithium normal", to look for any trends which might explain the differences. I also have a project under way to do detailed analyses of open cluster stars in order that we can better understand what is going on in them and how they work.
This object is actually a close binary system, made up of two chemically-peculiar (Am) stars. These have unusual abundances of elements such as iron (Fe), calcium (Ca), strontium (Sr) and other lanthanides. The study measured the abundances of a range of elements in both objects to see if they shared the same abundance patterns.
Lithium is an important element in astrophysics: accurate determination of its abundance in stars today, and extrapolation to the primordial abundance has implications for cosmology, stellar structure, stellar evolution and other branches of study.
Clusters for excellent laboratories for the study of star formation, evolution and structure, since they are composed of many objects with similar ages, distances, compositions and so on, and so most parameters relating to cluster stars can be found to a high degree of accuracy. This then limits the number of parameters available to explain observations to those which vary from star-to-star within clusters such as temperature or rotation) and to those parameters which vary between clusters, namely the metallicity and age.
Halo (Pop. II) stars
Pop. II stars are those which are predominantly found in a halo around the main plane of the Galaxy. They formed earlier in the evolution of the Galaxy, and so have lower metallicities than cluster stars, as well as being older and redder.
Their importance lies in the discovery of the `Spite plateau' (Spite & Spite, 1982) of Li abundances, which suggested that the amount of lithium in the Pop. II objects in the range of the plateau (Teff > 5800 K; [Fe/H] < -1.5 ) was uniform. If this were indeed the case, we would have a direct view of the amount of Li which was in these objects from the Big Bang, the primordial Li abundance or Lip. Unfortunately nothing is ever this simple, and recent investigations of the plateau suggest that it is not flat, instead sloping slightly with metallicity. This implies that the metal content of the material from which Pop. II stars formed was gradually enriched over the formation era for these objects. However, Li abundances in these stars are still our best indicator of Lip.
My studies focussed on the detection of Li in both Pop. I and Pop. II stars. Until recently, almost all Li abundances in main sequence objects has been derived from only one spectral line, the resonance feature at 6708A. My studies (in collaboration with my PhD supervisor Rob Jeffries, as well as Barry Smalley from Keele University) focussed around using the weaker Li subordinate line at 6104A to measure abundances. In theory, this weak line should be less subject to atmospheric inhomogeneities, NTLE effects, and other chromospheric effects which may alter the line or abundances determined from it than the 6708A feature. Our analysis has shown that abundances from the two lines are not in agreement, with the weaker line indicating larger Li abundances. We suspect that this is, at least in part, due to the presence of star spots on the young Pleiades objects, though we are still trying to explain our observations in the Pop. II stars.
(Ford et al. 2002a; Ford et al. 2002b, both in prep).
Finally, in addition to this work, we considered Li abundances in the Coma Berenices open cluster. Coma has a similar age to the Hyades, but a metallicity more like that of the Pleiades. Standard models predict that Li depletion is determined almost entirely by metallicity, with age playing a minor role. In practice, we found that the Coma abundances were much more like those of Hyades stars.
(Ford et al. 2001, A&A)
Conferences are a very important part of academic life: sharing of ideas, networking, and keeping up to date on all the latest developments are all imperative. To date my conference budget has been quite small, but I've managed to get to a few different events:
Following on from the Model Atmospheres meeting, Richard Ogley and I decided to set up the Keele Model Atmosphere Directory (K-MAD) to try to foster links between those who write models and those who use them, in addition to trying to keep track of what developments are made by the very diverse collection of people who work in this field.