Welcome to Zhao Guo (John)'s page
PhD in Astronomy, Dec 2016 (Georgia State University, USA)
Title: Asteroseismology in Binary Stars with Applications of Bayesian Inference Tools
Advisor: Douglas Gies
Committee: Rich Townsend, Fabien Baron, Russel White, Hal McAlister,Vadym Apalkov
Postdoc fellow in the asteroseismology group at the Copernicus Astronomical Center, Polish Academy of Sciences, Warsaw, Poland (Jan 2017 - July 2018, host: Gerald Handler)
Postdoc scholar, The Pennsylvania State Univeristy, Department of Astronomy and Astrophysics, USA (July 2018- Aug 2020, host: Eric Ford)
Research Associate, Department of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge, UK (Sep 2020- present, host: Gordon Ogilvie)
I am interested in both observational data reductions (photometry[Kepler], spectroscopy[KPNO, APO, Keck] and interferometry[CHARA array]) and theoretical interpretations.
My research frequently uses the MESA stellar evolution code and the GYRE oscillation code.
I am involved in the further development of the GYRE oscilation code to include the tidal effect. A demo can be found Here.
Exoplanet Host Stars and Eclipsing Binaries ( especially those with pulsating components, such as δ Scuti / γ Doradus Stars,
Paper1, 2, 3 Slowly Pulsating B stars / β Cephei stars Paper4, solar-like oscillators Paper4,and Cataclysmic Variables Paper1,
Binary Star Evolution with Mass Transfer Paper1,Paper2
Tidally Excited Oscillations in Heartbeat Binaries ("Tidal Asteroseismology") Paper1 ,2 ,3 ,4
Nonlinear Asteroseismology Paper1
Optical Interferometry and Asteroseismology of Delta Scuti Stars Slides for the talk in Nice, France
Bayesian Inference (e.g., hierarchical models, model comparison) SCMA,Poster1,Paper1, Chapter8
Inverse Problems (Tomography, Asteroseismic Inversion) Chapter9
Time Series Analysis, Machine Learning
Reviewer for ApJ, AJ, ApJS, MNRAS, A&A, Nature Astronomy, RMxAA
My ADS library
Please feel free to drop me an email, I am happy to talk with interested collaborators.
Asteroseismology of Close Binary Stars: Tides and Mass Transfer (PIMMS workshop, Surrey, UK, Jan 2021)
A table of 22 Heartbeat Binaries with TEOs (Guo 2021, Frontiers in Astronomy and Space Sciences)
Modeling the stellar granulation and oscillation in the RV time series: A Fourier method (Queen's University Belfast, Nothern Ireland, Nov 2020)
Asteroseismology of Binary Stars (Lehigh University, Oct 2019)
Asteroseismology of Binary Stars (Georgia State University, Atlanta, Oct 2019)
Granulation in Radial Velocities and Linear Inverse Problems (Yale University, New Haven, Oct 2019) (Invited Seminar)
Asteroseismology of Binary Stars (Yale University, New Haven, Oct 2019) (Invited)
Asteroseismology of Binary Stars (University of Virginia & URAO, Charlottesville, Sept 2019) (Invited Colloquium)
Listening to the Heartbeat (Stars and their variabilities, Vienna, Austria, Aug 2019) (Invited talk)
Tidal Asteroseismology: Challenges and Opprortunities (TASC5/KASC12 meeting, MIT, July 2019)
The variability of TESS eclipsing binaries (TESS science conference, MIT, July 2019)
Listening to the Heartbeat: Tidal Asteroseismology (Science Talk, University of Wisconsin-Madison, March 2019)
Inverse Problems in Asteroseismology and Binary Star Spectroscopy (Math + X Symposium on Inverse Problems and Deep Learning in Space Exploration, Rice University, Houston, Jan 2019)
Tidal Asteroseismology of Heartbeat Stars (Physics of Oscillating Stars, Banyuls-sur-mer, France, Sept 2018)
Asteroseismology of Binary Stars: Mass Transfer and Tides ( TASC4/KASC11 meeting, Aarhus University, Denmark, July 2018 )
Asteroseismology of Delta Scuti Stars ( University of Granada, Granada, Spain, June 2018 )
Asteroseismology of Binary Stars ( Max Planck Institute for Solar System Research, Gottingen, Germany, Mar 2018 )
Asteroseismology of Binary Stars: Mass Transfer and Tidally Excited Oscillations ( Max Planck Institue for Astrophysics, Munich, Germany Jan 2018 )
Asteroseismology and Interferometry of Delta Scuti Stars ( Observatoire de la Cote d'Azur, Nice, France, Oct 2017 )
Planet Induced Stellar Pulsations ( Copernicus Astronomical Center, Polish Academy of Sciences, Warsaw, Poland, Mar 2017 )
Pulsations in Binary Stars: Delta Scuti/Gamma Dor Pulsators and Tidally Induced Heartbeat Stars ( IAU Focus Meeting 17, Hawaii, USA, 2015 )
Stellar Evolution in a Nutshell ( Georgia State University, Atlanta, USA, June 2015 )
The IDL code to reconstruct the individual component spectra in spectroscopic binaries.tomography is the original version
in wavelength domain by Gies & Wiemker. The new code tomoft and tomoftregu are in Fourier domain.
tomoregu includes Tikhonov regularization and a prior estimation of the spectrum is needed, it can give better
reconstructions for faint components. For examples and Tutorials,please see Chapter9.
My PhD Dissertation
The MATLAB code to calculate adiabatic tidal eigenfunctions of forced oscillations following the algorithm in GYRE (Townsend&Teitler 2013) and
the expressions in Valsecchi et al. (2013).
The non-adiabatic eigenfunctions can be calculated by a revised version of GYRE code, please see my poster.
For details,please refer to Chapter3.
The JAGS/STAN code to analyze the radial velocity data in binaries with hierarchical Bayesian models. The model can be used to model RV data with red noise.
Four files are required: data, initial,
The RV data are given in the data file.The inital parameters are given in the initial file.The statistical model is decribed
in model file in BUGS language. The scripte file specifies which parameters to monitor and details of the Markov chain.
Examples and Tutorials, please see Chapter8.