193 citations · 1.4k across the 56 of their papers we have counts for
56 papers
A Diagnostic Method for Proto-Neutron Star Magnetic Fields by Supernova Fallback Neutrinos
Akihiro Inoue, Yudai Suwa, Ryuichiro Akaho +3
Young isolated neutron stars exhibit a wide range of magnetic field strengths. To understand the origin of this diversity, it is important to observationally constrain magnetic fie…
Asymmetric, variable H line profile in planetary mass object SR 12 c
Jun Hashimoto, Yuhiko Aoyama, Michihiro Takami +1
Young, forming planetary-mass objects often exhibit clear signatures of ongoing mass accretion and are thought to accrete material through processes analogous to those operating in…
Cosmic ray heating of cold streams: Implications for the gas supply and growth of massive galaxies
Ellis R. Owen, Nicolas Ledos, Evangelia Ntormousi +3
Recent observations have demonstrated the presence of cosmic rays (CRs) in cosmic-web filaments. Cold streams supply gas inflows from these filaments into massive galaxies during t…
Numerical Investigation of Efficient Electron Acceleration at an Unsteady Solar Flare Loop-Top
Yoshiaki Sato, Takafumi Kaneko, Noriyuki Narukage +1
Using magnetohydrodynamic (MHD) fields and guiding-center test-particle calculations, this study investigates how time-dependent loop-top dynamics modulate the adiabatic energizati…
A Magnetized Black Hole Envelope Model for Little Red Dots
Shinsuke Takasao, Kohei Inayoshi
Recent observations have revealed a unique class of active galactic nuclei (AGNs), termed little red dots (LRDs). These objects are hypothesized to be powered by massive black hole…
Systematic Comparison between Constrained Transport and Mixed Divergence Cleaning Methods for Astrophysical Magnetohydrodynamic Simulations
Kengo Tomida, Kenji Eric Sadanari, Shinsuke Takasao +1
Magnetohydrodynamic (MHD) simulations are indispensable research infrastructure in astrophysics today. In order to satisfy the solenoidal constraint of the MHD equations on discret…
The hydrodynamical response of cold circumgalactic clouds to quasar radiation
Nicolas Ledos, Sebastiano Cantalupo, Titouan Lazeyras +8
Recent simulations increasingly resolve the small-scale structure of the circumgalactic medium (CGM), but the dynamical impact of ionising radiation on its cold K component…
The mass distribution of clumpy accretion onto the nearby young star TW Hya
Tao Ji, Javier Serna, Gregory J. Herczeg +12
The proliferation of high time-resolution and decades-long monitoring of classical T Tauri stars provides a vast opportunity to test the variability of the star-disk connections. H…
X-ray emission of F-type stars and its analogy with G-type stars
Takuma Shimura, Ikuyuki Mitsuishi, Masanobu Kunitomo +3
We conducted a systematic spectral study for single F-type main-sequence (MS) stars without significant X-ray outbursts to investigate X-ray spectral properties such as temperature…
A Necessary Condition for the Submergence of Proto-Neutron Star Magnetic Fields by Supernova Fallback
Akihiro Inoue, Shinsuke Takasao, Kazumi Kashiyama +2
Central compact objects (CCOs) are a subclass of neutron stars with a dipole magnetic field strength considerably weaker than those of radio pulsars and magnetars. One possible exp…
Model of X-ray and extreme-UV emission from magnetically heated atmospheres in classical T Tauri stars: Case study of TW Hya
Munehito Shoda, Riouhei Nakatani, Shinsuke Takasao
Photoevaporation caused by X-rays and ultraviolet radiation from the central star has attracted attention as a key process driving the dispersal of protoplanetary discs. Although n…
Connecting a Magnetized Disk to a Convective Low-mass Protostar: A Global Three-dimensional Model of Boundary Layer Accretion
Shinsuke Takasao, Takashi Hosokawa, Kengo Tomida +1
In the early stages of star formation, boundary layer accretion, where protostars accrete material from disks extending down to their surfaces, plays a crucial role. Understanding…
Evidence for Variable Accretion onto PDS 70 c and Implications for Protoplanet Detections
Yifan Zhou, Brendan P. Bowler, Aniket Sanghi +14
Understanding the processes of planet formation and accretion in young systems is essential to unraveling the initial conditions of planetary systems. The PDS 70 system, which host…
NuSTAR detection of a hot stellar superflare with a temperature of 95 MK in hard X-rays
Tomohiro Hakamata, Hironori Matsumoto, Hirokazu Odaka +1
A search of the hard X-ray archive data of NuSTAR found a transient source, NuSTAR J230059+5857.4, during an observation of 1E 2259+586 on 2013 April 25. A multi-wavelength analysi…
Spin-down of solar-mass protostars in magnetospheric accretion paradigm
Shinsuke Takasao, Masanobu Kunitomo, Takeru K. Suzuki +2
Stellar spin is one of the fundamental quantities that characterize a star itself and its planetary system. Nevertheless, stellar spin-down mechanisms in protostellar and pre-main-…
Assessing the capability of a model-based stellar XUV estimation
Munehito Shoda, Kosuke Namekata, Shinsuke Takasao
Stellar XUV (X-ray and extreme ultraviolet) emission drives the heating and chemical reactions in planetary atmospheres and protoplanetary disks, and therefore, a proper estimation…
Magnetising galaxies with cold inflows
Nicolas Ledos, Evangelia Ntormousi, Shinsuke Takasao +1
High-redshift () galaxies accrete circumgalactic gas through cold streams. Recent high-resolution MHD simulations of these streams showed a significant amplification of t…
Broadening the Canonical Picture of EUV-Driven Photoevaporation of Accretion Disks
Riouhei Nakatani, Neal J. Turner, Shinsuke Takasao
Photoevaporation driven by hydrogen-ionizing radiation, also known as extreme-ultraviolet (EUV), profoundly shapes the lives of diverse astrophysical objects. Focusing here mainly…
Effect of time-varying X-ray emission from stellar flares on the ionization of protoplanetary disks
Haruka Washinoue, Shinsuke Takasao, Kenji Furuya
X-rays have significant impacts on cold, weakly ionized protoplanetary disks by increasing the ionization rate and driving chemical reactions. Stellar flares are explosions that em…
Upper Limit on the Coronal Cosmic Ray Energy Budget in Seyfert Galaxies
Yoshiyuki Inoue, Shinsuke Takasao, Dmitry Khangulyan
The IceCube collaboration has reported possible detections of high-energy neutrinos from nearby Seyfert galaxies. While central hot coronae are proposed as the primary neutrino pro…
Dynamics Near the Inner Dead-Zone Edges in a Proprotoplanetary Disk
Kazunari Iwasaki, Kengo Tomida, Shinsuke Takasao +2
We perform three-dimensional global non-ideal magnetohydrodynamic simulations of a protoplanetary disk containing the inner dead-zone edge. We take into account realistic diffusion…
The optically thick rotating magnetic wind from a massive white dwarf merger product -- II. axisymmetric magnetohydrodynamic simulations
Yici Zhong, Kazumi Kashiyama, Shinsuke Takasao +2
We numerically construct a series of axisymmetric rotating magnetic wind solutions, aiming at exploring the observation properties of massive white dwarf (WD) merger remnants with…
Magnetic field transport in geometrically thick discs: multi-dimensional effects on the field strength and inclination angle
Ryoya Yamamoto, Shinsuke Takasao
We theoretically investigate the magnetic flux transport in geometrically thick accretion discs which may form around black holes. We utilize a two-dimensional (2D) kinematic mean-…
Twenty-Five Years of Accretion onto the Classical T Tauri Star TW Hya
Gregory J. Herczeg, Yuguang Chen, Jean-Francois Donati +39
Accretion plays a central role in the physics that governs the evolution and dispersal of protoplanetary disks. The primary goal of this paper is to analyze the stability over time…