About

Olivia Jones Hong-Kong in Jodcast T-shirt

Dr. Olivia Jones

I am a post-doctoral research fellow at the Space Telescope Science Institute, working with Dr. Margaret Meixner. I started working at STScI in August 2014, after a short postdoc at the Jodrell Bank Centre for Astrophysics. I was here where I also completed my PhD on dusty evolved stars under the guidance of Dr. Ciska Kemper and Professor Albert Zijlstra.

My research interests include the production of dust in evolved stars, the life cycle of dust in galaxies and the stellar population of local group galaxies. The vast majority of my research involves analysing Spitzer spectroscopy and photometry as part of the Spitzer SAGE collaboration.

You can listen to me talk about my research on the April 2014 Extra Jodcast.

Email: ojones-AT-stsci.edu

Research

My main area of research is dusty AGB stars, these are low to intermediate mass stars that up till now have had a quiet life on the main sequence. In their old age once the star has exhausts its supply of hydrogen in its core, the core contracts and its temperature increases, causing the outer layers of the star to expand and cool, after traversing both the red giant branch and the horizontal branch, the star reaches its final evolutionary stage the asymptotic giant branch (AGB). An AGB stars life is very interesting, it becomes luminous, pulsates and develops an intense mass-loosing stellar wind. This extensive mass loss creates an extended circumstellar envelope of gas and dust which surrounds the star, and obscures it from view.

In the outer layers of the AGB stars circumstellar envelope lots of interesting chemical reactions occur and star dust forms. Around oxygen-rich AGB stars (where the C/O ratio < 1) the dust tends to be composed of silicates (both in chaotic lattice structures [Amorphous silicates] or in regulated arrangements [Crystalline silicates]), alumina rich species (such as sapphire) and iron. While around Carbon-rich stars (C/O >1) amorphous Carbon, SiC and MgS dominate the dust production. I am particularly interested the chemical composition and abundances of dust as a function of the metallicity (the ratio of heavy elements to helium), in order to understand the chemical evolution and enrichment of the Universe.

Cool dusty stars emit radiation in the infrared, thus using infrared cameras on board the Spitzer Space Telescope and the (soon to be launched) JWST the dust producing evolved stellar populations of Local Group galaxies can be observed. This allows evolved stars to be characterised on a galactic scale and constraints put on the chemical content of the existing stars e.g. the fraction of stars which are Carbon or oxygen rich. It also enables total dust-production rates to be calculated and the impact these sources have on the dust budget of galaxies can be assessed.

Publications

  • ORCID: 0000-0003-4870-5547

  • 2017

    2016

    2015

    2014

    2013

    2012

    2011

    2010

    2009


    External Talks

      Keel University, UK; June 2016

      Onsala Space Observatory, Sweden; June 2016

      JBCA, UK; November 2015

      Leeds, UK; January 2014

      ASIAA, Taiwan; Febuary 2013

      Leiden Observatory, The Netherlands; January 2012


    Teaching

      2016   Supervisor to STScI summer student: Mathew Maclay

      2015   Supervisor to STScI summer student: Helen Meskhidze


    Alumina-Silicate Model Grid

      If you wish to use the grid of Alumina and silicate models for oxygen-rich evolved stars published in Jones et al. 2014 please drop me an email. The grid, generated using the Modust radiative transfer code, samples a range of stellar and dust shell parameters and is optimized for oxygen-rich dusty evolved stars. This grid is best used to investigate the dust composition as a function of the dust-production rate.

    Outreach

    Jodcast

    The Jodcast was the UK's first astronomy podcast and is produced by astronomers based at Jodrell Bank Observatory and JBCA. I made my Jodcast presenting debut on the July 2010 Extra show and haven't looked back. My favourite jodcast event so far was the e-merlin road trip visiting all the e-merlin telescopes in a day and filming the trip to explain how interferometers work. In the summer of 2014 I hung up my Jodcast recorder (but not my t-shirt) for pastures new, but maybe you will here me in the occasional future episode.



    Libby et al. at the e-merlin Defford Telescope



    Libby putting a stick through a baloon without it bursting.

    Other Outreach

    Other public engagement events to do with with astronomy and science include:

    Connect

    Space Telescope Science Institute (STScI)
    3700 San Martin Drive
    Baltimore, MD 21218
    USA

    Email: ojones-AT-stsci.edu