Mairi O'Brien
I am a second-year PhD student in the Astronomy & Astrophysics group at the University of Warwick. My supervisor is Pier-Emmanuel TremblayLink opens in a new windowLink opens in a new window. I began my PhD in October 2021.
My Research
I have contributed to the creation of a volume-complete sample of white dwarfs within 40 pc, where candidates were identified using GaiaLink opens in a new windowLink opens in a new window EDR3. I have analysed a subsample of white dwarf candidates with X-ShooterLink opens in a new window spectroscopy, identifying almost 200 new white dwarfs with a variety of features and compositions. By fitting the atmospheric parameters of these white dwarfs, I can learn about their properties including their mass, temperature and cooling age. We need to know the spectral classification of each white dwarf so we can use pure-H, pure-He or mixed H/He model atmospheres to accurately calculate their properties.
The 40 pc White Dwarf Sample
The 40 pc sample now has 97% spectroscopic completeness, and is the largest volume-complete sample of white dwarfs to date. The sample can be used for statistical analysis to learn more about white dwarfs and their evolution.
The sample has already been used to look at the local stellar formation history of our Galaxy.
Please contact me if you would like to make use of the 40 pc sample.
Publications
First-author:
M. W. O'Brien et al. “Contributing:
E. Cukanovaite et al. “Local stellar formation history from the 40 pc white dwarf sampleLink opens in a new windowLink opens in a new window". In: MNRAS (Submitted Sept. 2022). arXiv: 2209.13919Link opens in a new windowLink opens in a new window [astro-ph.SR]S. Scaringi et al. “Localized thermonuclear bursts from accreting magnetic white dwarfsLink opens in a new windowLink opens in a new window". In: Nature 604, 447–450 (Apr. 2022). DOI: 10.1038/s41586-022-04495-6. arXiv: 2204.09070 [astro-ph.HE]
Data
Table 3 from my paper O'Brien et al. (2023) is available to download in csv format hereLink opens in a new window.
Conferences
National Astronomy Meeting, July 2022 - Warwick, UK: Completing the 40 pc sample of Gaia white dwarfs. Parallel Session Talk.
EuroWD22, August 2022 - Tübingen, Germany: Completing the 40 pc sample of Gaia white dwarfs. Talk.
Stellar Evolution along the HR Diagram with Gaia, September 2022 - Naples, Italy. Attended.
Teaching and Responsibilities
2021-2022 and 2022-2023: Lab demonstrator for the undergraduate physics module PX152 Physics LaboratoryLink opens in a new window.
2021-2022 and 2022-2023: Exam Invigilator in the Physics Department.
2021-2022: Organiser of our weekly White Dwarf Group Meetings.
2022-2023: Committee member (Speaker Liaison) for the Warwick Astronomy Equitea group.
2022-2023: Physics Postgraduate Wellbeing Rep.
Other Interests
I completed a masters' project at Durham University in 2021 where I helped to uncover a new type of stellar explosion - micronovaeLink opens in a new window.
I am the Physics Postgraduate Wellbeing Rep, and I organise weekly wellbeing coffee sessions for the postgraduate students in our department.
I helped with the organisation of the Warwick Astronomy Knowledge Exchange (WAKELink opens in a new windowLink opens in a new window) programme in 2022. I helped to run a workshop and organised group introduction sessions with our white dwarf group.
Write to:
Mairi O'Brien,
Department of Physics,
University of Warwick,
Coventry CV4 7AL