4 citations · 13 across the 15 of their papers we have counts for
8 papers · 1 filter
Bayesian Doppler Imaging: Simultaneous Inference of Surface Maps and Geometric Parameters
Yamato Ureshino, Hajime Kawahara, Hibiki Yama +1
We present a fully Bayesian, pixel-based Doppler imaging framework that enables the simultaneous inference of surface brightness maps and geometric parameters, including the inclin…
ExoJAX Retrievals of VLT/CRIRES Spectra of Luhman 16AB: C/O Ratios and Systematic Uncertainties
Hibiki Yama, Kento Masuda, Yui Kawashima +1
We present atmospheric retrievals of the benchmark brown dwarf binary Luhman 16AB using high-resolution VLT/CRIRES spectra and the differentiable framework ExoJAX. We derive elemen…
microJAX: A Differentiable Framework for Microlensing Modeling with GPU-Accelerated Image-Centered Ray Shooting
Shota Miyazaki, Hajime Kawahara
We introduce microJAX, the first fully differentiable implementation of the image-centered ray-shooting (ICRS) algorithm for gravitational microlensing. Built on JAX and its XLA ju…
Unveiling the Atmosphere of HR 7672 B from the Near-Infrared High-Resolution Spectrum Using REACH/Subaru
Yui Kasagi, Yui Kawashima, Hajime Kawahara +12
Characterizing the atmospheres of exoplanets and brown dwarfs is crucial for understanding their atmospheric physics and chemistry, searching for biosignatures, and investigating t…
Measurement of Methane Line Broadening in Hot Hydrogen/Helium Atmospheres at = 1.60-1.63 μm for Substellar Object Spectroscopy
Ko Hosokawa, Takayuki Kotani, Hajime Kawahara +4
Recent high-dispersion spectroscopy from ground-based telescopes and high-precision spectroscopy from space observatories have enabled atmospheric observations of substellar object…
Probing Two-dimensional Asymmetries of an Exoplanet Atmosphere from Chromatic Transit Variation
Shotaro Tada, Hajime Kawahara, Yui Kawashima +2
We propose a new method for investigating atmospheric inhomogeneities in exoplanets through transmission spectroscopy. Our approach links chromatic variations in conventional trans…
Atmospheric retrieval of Subaru/IRD high-resolution spectrum of the archetype T-type brown dwarf Gl 229 B
Yui Kawashima, Hajime Kawahara, Yui Kasagi +14
Brown dwarfs provide a unique opportunity to study atmospheres and their physical and chemical processes with high precision, especially in temperature ranges relevant to exoplanet…
Differentiable Modeling of Planet and Substellar Atmosphere: High-Resolution Emission, Transmission, and Reflection Spectroscopy with ExoJAX2
Hajime Kawahara, Yui Kawashima, Shotaro Tada +11
Modeling based on differentiable programming holds great promise for astronomy, enabling advanced techniques such as gradient-based posterior sampling and optimization. This paradi…