Elizabeth Tasker

I am a theoretical astrophysicist, specialising in the formation of stars and planets. 

 
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Stars are born in cold clouds of gas known as the Giant Molecular Clouds. These stellar nurseries determine the rate stars are born, yet what controls their evolution is less clear. My research group models their formation in different environments, using the astrophysics simulation code Enzo. Enzo is known as a hydrodynamical, adaptive mesh refinement code. In more sensible terms, this means the code models the gas on a series of grids whose cell size changes depending on what resolution is required.  

My more recent work on planet formation focusses on understanding exoplanet diversity. At the moment, our data on exoplanets is usually limited to size and insolation level (the amount of radiation the planet receives from the star). The fact this is a poor indication of planet conditions can be easily demonstrated within our own Solar System: Venus is very close to the Earth in size and mass and receives only slightly more radiation from the Sun. A guess at the surface temperature if we saw Venus as an exoplanet might be in the region of 27 Celsius: perfect beach weather temperature! Yet, Venus's true surface temperature exceeds 450 Celsius; lead-melting conditions that point to a wildly different evolution. 

In my current projects, I have been exploring trends in the current data to try and impute missing data values using neural networks. With my student, Ngan Nguyen, we have also been looking at how planets migrate during the early years of their formation, changing their orbits such that planets found on similar paths may not have similar histories.

This video was filmed at Hokkaido University while I was an assistant professor in the Faculty of Science. The full video can be found here.

After a week long systems science workshop about the search for habitable worlds, Elizabeth Tasker (ISAS/JAXA) hosts a panel discussion of astrobiologists to discuss the myriad approaches to understanding the search for life in the universe.
 

Earth-Like: exploring the diversity of planets very like our own 

One project we recently developed for outreach and education is ‘Earth-Like’: an interactive website where you can alter the coverage of surface water, rate of volcanism and location within the habitable zone around a star (effectively, the amount of radiation received by the planet) and calculate the resulting surface temperature.

Earth-Like models a simple carbon-silicate cycle to move carbon between the atmosphere, oceans and sediment. The more carbon rich atmosphere results in a higher fraction of carbon dioxide; a greenhouse gas that acts as a thermal blanket to keep the planet warm.

While we do not know yet if the exoplanets we have discovered might have such similar geological cycles as our own, it is interesting to explore how different even a very Earth-Like planet could be from our own.

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Teaching & Research Grants

 

From 2012 - 2016, I taught two physics courses at Hokkaido University. These lectures covered core physics topics for first year undergraduates, including classical mechanics, vibrations, waves, optics, thermodynamics, electromagnetism and a touch of quantum mechanics.

Since most of my students were not native-level English speakers, my courses used keynote presentations that included many graphics and movies. I also used the clicker system for in-class questions (keeps students awake and allows me a 5 minute break!). Three or four times during the semester, we watched short movies and read science news stories to see physics beyond the first year syllabus.

I was delighted to be awards the Hokkaido University President's Award for Education in 2014, 2015 and 2016 and be listed as an Excellent Teacher for those last three years.

I’ve also held the following national-level grants:

[2013 - 2016] Ministry of Education Culture, Sports, Science & Technology, Program to Disseminate Tenure-Track System (文部科学省 「テニュアトラック普及・定着事業」). 15 million yen / year grant for tenure-track level faculty.

[2014] Suhara Memorial Foundation / 寿原記念財団 for development and promotion of science in Hokkaido. 1,000,000 yen.

[2016 - 2020] Grants-in-Aid for Scientific Research (Kakenhi / 科研費): Young Scientist B / 若手研究(B). Four year grant for researchers under 39 years old: total amount 4,160,000 yen.

A research talk I gave at the Otaru University of Commerce in Hokkaido, Japan to students from mixed disciplines. 

Recent Journal Papers

  1. The impact of galactic disc environment on star-forming clouds, Nguyen, Ngan K.; Pettitt, Alex R.; Tasker, Elizabeth J.; Okamoto, Takashi. MNRAS, 03/2018

  2. The effect of photoionizing feedback on star formation in isolated and colliding clouds, Shima, Kazuhiro; Tasker, Elizabeth J.; Federrath, Christoph; Habe, Asao, PASJ, 05/2018

  3. The language of exoplanet ranking metrics needs to change,
    Tasker, Elizabeth; Tan, Joshua; Heng, Kevin; Kane, Stephen; Spiegel, David; Brasser, Ramon; Casey, Andrew; Desch, Steven; Dorn, Caroline; Hernlund, John; Houser, Christine; Laneuville, Matthieu; Lasbleis, Marine; Libert, Anne-Sophie; Noack, Lena; Unterborn, Cayman; Wicks, June.
    Nature Astronomy, 02/2017

 
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Curriculum Vitae

 

employment

[2016 - ] Japan Aerospace Exploration Agency (JAXA), Institute for Space and Astronautical Sciences (ISAS)
Associate Professor in the Division of Solar System Sciences

[2011 - 2016] Hokkaido University, Japan
Assistant/Associate Professor in the Department of Physics, Faculty of Science

[2009 - 2011] McMaster University, Canada
CITA National Postdoctoral Fellow

[2006 - 2009] University of Florida, USA
Theoretical Astrophysics Postdoctoral Fellow

 

education

[2006] University of Oxford, UK
D.Phil in computational astrophysics

[2002] Durham University, UK
M.Sci (Hons) Theoretical Physics