4 citations · 13 across the 15 of their papers we have counts for
15 papers
DOLPHIN (Device of Line Photometry in Nasmyth): A Switchable Multiband Photometer for the ISAS 1.3-m Telescope
Kohei Miyakawa, Hirokazu Kataza, Teruyuki Hirano +3
We present the design, construction, and commissioning of DOLPHIN (Device of Line Photometry in Nasmyth), a compact instrument for switchable broad- and narrow-band photometry at t…
GREX-PLUS Science Book v2
PLUS Science Team, Shunsuke Baba, Sirio Belli +52
GREX-PLUS (Galaxy Reionization EXplorer and PLanetary Universe Spectrometer) is a mission candidate for a JAXA strategic L-class mission to be launched in the 2030s. Its primary sc…
Japan's Possible Contributions for Coronagraph of the Habitable Worlds Observatory (HWO)
Keigo Enya, Kenta Yoneta, Naoshi Murakami +20
In this paper, we describe Japan's possible contributions for coronagraph of the Habitable Worlds Observatory (HWO) based on our independent study. We are considering to contribute…
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…
Discovery of a Low-Mass Companion to the Accelerating Star HIP 53005 with Strongly Conflicting Mass Estimates
Taichi Uyama, Thayne Currie, Jerry W. Xuan +22
We present the discovery of a low-mass companion located at 0\farcs{}85 () from the early-type 1.2 Gyr-old star HIP 53005 using direct imagin…
PyIRD: A Python-Based Data Reduction Pipeline for Subaru/IRD and REACH
Yui Kasagi, Hajime Kawahara, Ziying Gu +4
PyIRD is a Python-based pipeline for reducing spectroscopic data obtained with IRD (InfraRed Doppler; Kotani et al. (2018)) and REACH (Rigorous Exoplanetary Atmosphere Characteriza…
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…
Weighing Single-lined Spectroscopic Binaries Using Tidal Effects on Radial Velocities: The Case of V723 Monocerotis
Mio Tomoyoshi, Kento Masuda, Teruyuki Hirano +6
In single-lined spectroscopic binaries (SB1s) where flux variations due to tidal deformation of the primary star (ellipsoidal variations, EVs) are detected, the binary mass can be…
JASMINE image simulator for high-precision astrometry and photometry
Takafumi Kamizuka, Hajime Kawahara, Ryou Ohsawa +23
JASMINE is a Japanese planned space mission that aims to reveal the formation history of our Galaxy and discover habitable exoEarths. For these objectives, the JASMINE satellite pe…
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…