Welcome to Zhao (John) Guo'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
I am now a post-doc fellow in the asteroseismology group at Copernicus Astronomical Center, Warsaw, Poland, collaborating with Gerald Handler, Alexey Pamyatnykh and Wojciech Dziembowski.
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 GYRE to include the dynamical tidal effect.
Exoplanet Host Stars and Eclipsing Binaries ( especially those with pulsating components, such as δ Scuti / γ Doradus Stars, Slowly Pulsating B stars / β Cephei stars, solar-like oscillators, and Cataclysmic Variables.) Paper1, 2, 3
Binary Star Evolution with Mass Transfer Paper1
Tidally Induced Pulsations in Eccentric Binaries ("Tidal Asteroseismology") Paper1
Optical Interferometry and Asteroseismology of Delta Scuti Stars
Bayesian Inference (e.g., hierarchical models, model comparison) SCMA,Poster1,Paper1, Chapter8
Inverse Problems (Tomography, Asteroseismic Inversion) Chapter9
Time Series Analysis, Machine Learning
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 needed: 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.