研究成果・発表論文

Three-dimensional radiative properties of hot accretion flows on to the Galactic Centre black hole

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Kato, Y.,   Umemura, M.,   Ohsuga, K.

By solving the radiative transfer equations, we examine the three- dimensional radiative properties of a magnetohydrodynamic accretion flow model conforming to the observed spectrum of Sgr A* in the vicinity of the supermassive black hole at the Gala...

Cosmological radiative transfer comparison project - II. The radiation-hydrodynamic tests

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Iliev, Ilian T.,   Whalen, Daniel,   Mellema, Garrelt,   Ahn, Kyungjin,   Baek, Sunghye,   Gnedin, Nickolay Y.

The development of radiation hydrodynamical methods that are able to follow gas dynamics and radiative transfer (RT) self- consistently is key to the solution of many problems in numerical astrophysics. Such fluid flows are highly complex, rarely all...

The escape of ionizing photons from supernova-dominated primordial galaxies

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Yajima, Hidenobu,   Umemura, Masayuki,   Mori, Masao,   Nakamoto, Taishi

In order to assess the contribution of Lyman break galaxies (LBGs) and Lyman \ensuremathα emitters (LAEs) at redshifts 3 < z < 7 to the ionization of intergalactic medium (IGM), we investigate the escape fractions of ionizing photons from super...

Formation of globular clusters induced by external ultraviolet radiation

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Hasegawa, Kenji,   Umemura, Masayuki,   Kitayama, Tetsu

We present a novel scenario for globular cluster (GC) formation, where the ultraviolet (UV) background radiation effectively works so as to produce compact star clusters. Recent observations on the age distributions of GCs indicate that many GCs form...

Global Radiation-Magnetohydrodynamic Simulations of Black-Hole Accretion Flow and Outflow: Unified Model of Three States

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Ohsuga, Ken,   Mineshige, Shin,   Mori, Masao,   Kato, Yoshiaki

Black-hole accretion systems are known to possess several distinct modes (or spectral states), such as low/hard state, high/soft state, and so on. Since the dynamics of the corresponding flows is distinct, theoretical models were separately discussed...

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Three-dimensional radiative properties of hot accretion flows on to the Galactic Centre black hole

Kato, Y.,   Umemura, M.,   Ohsuga, K.

By solving the radiative transfer equations, we examine the three- dimensional radiative properties of a magnetohydrodynamic accretion flow model conforming to the observed spectrum of Sgr A* in the vicinity of the supermassive black hole at the Gala...

平成21年 12月   Monthly Notices of the Royal Astronomical Society
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Cosmological radiative transfer comparison project - II. The radiation-hydrodynamic tests

Iliev, Ilian T.,   Whalen, Daniel,   Mellema, Garrelt,   Ahn, Kyungjin,   Baek, Sunghye,   Gnedin, Nickolay Y.

The development of radiation hydrodynamical methods that are able to follow gas dynamics and radiative transfer (RT) self- consistently is key to the solution of many problems in numerical astrophysics. Such fluid flows are highly complex, rarely all...

平成21年 12月   Monthly Notices of the Royal Astronomical Society
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The escape of ionizing photons from supernova-dominated primordial galaxies

Yajima, Hidenobu,   Umemura, Masayuki,   Mori, Masao,   Nakamoto, Taishi

In order to assess the contribution of Lyman break galaxies (LBGs) and Lyman \ensuremathα emitters (LAEs) at redshifts 3 < z < 7 to the ionization of intergalactic medium (IGM), we investigate the escape fractions of ionizing photons from super...

平成21年 9月   Monthly Notices of the Royal Astronomical Society
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Formation Criteria and the Mass of Secondary Population III Stars

Susa, Hajime,   Umemura, Masayuki,   Hasegawa, Kenji

We explore the formation of secondary Population III (Pop III) stars under radiation hydrodynamic (RHD) feedback by a preformed massive star. To properly treat RHD feedback, we perform three- dimensional RHD simulations incorporating the radiative tr...

平成21年 9月   The Astrophysical Journal
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Formation of globular clusters induced by external ultraviolet radiation

Hasegawa, Kenji,   Umemura, Masayuki,   Kitayama, Tetsu

We present a novel scenario for globular cluster (GC) formation, where the ultraviolet (UV) background radiation effectively works so as to produce compact star clusters. Recent observations on the age distributions of GCs indicate that many GCs form...

平成21年 8月   Monthly Notices of the Royal Astronomical Society
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Global Radiation-Magnetohydrodynamic Simulations of Black-Hole Accretion Flow and Outflow: Unified Model of Three States

Ohsuga, Ken,   Mineshige, Shin,   Mori, Masao,   Kato, Yoshiaki

Black-hole accretion systems are known to possess several distinct modes (or spectral states), such as low/hard state, high/soft state, and so on. Since the dynamics of the corresponding flows is distinct, theoretical models were separately discussed...

平成21年 6月   Publications of the Astronomical Society of Japan
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Radiative regulation of Population III star formation

Hasegawa, K.,   Umemura, M.,   Susa, H.

We explore the impact of ultraviolet (UV) radiation from massive Population III (Pop III) stars of 25, 40, 80 and 120M$_solar$ on the subsequent Pop III star formation. In this paper, particular attention is paid to the dependence of radiative feedba...

平成21年 5月   Monthly Notices of the Royal Astronomical Society

Three-dimensional radiative properties of hot accretion flows on to the Galactic Centre black hole

Kato, Y.,   Umemura, M.,   Ohsuga, K.
平成21年 12月   Monthly Notices of the Royal Astronomical Society

Cosmological radiative transfer comparison project - II. The radiation-hydrodynamic tests

Iliev, Ilian T.,   Whalen, Daniel,   Mellema, Garrelt,   Ahn, Kyungjin,   Baek, Sunghye,   Gnedin, Nickolay Y.
平成21年 12月   Monthly Notices of the Royal Astronomical Society

The escape of ionizing photons from supernova-dominated primordial galaxies

Yajima, Hidenobu,   Umemura, Masayuki,   Mori, Masao,   Nakamoto, Taishi
平成21年 9月   Monthly Notices of the Royal Astronomical Society

Formation Criteria and the Mass of Secondary Population III Stars

Susa, Hajime,   Umemura, Masayuki,   Hasegawa, Kenji
平成21年 9月   The Astrophysical Journal

Formation of globular clusters induced by external ultraviolet radiation

Hasegawa, Kenji,   Umemura, Masayuki,   Kitayama, Tetsu
平成21年 8月   Monthly Notices of the Royal Astronomical Society

Global Radiation-Magnetohydrodynamic Simulations of Black-Hole Accretion Flow and Outflow: Unified Model of Three States

Ohsuga, Ken,   Mineshige, Shin,   Mori, Masao,   Kato, Yoshiaki
平成21年 6月   Publications of the Astronomical Society of Japan

Radiative regulation of Population III star formation

Hasegawa, K.,   Umemura, M.,   Susa, H.
平成21年 5月   Monthly Notices of the Royal Astronomical Society