Masashi Umemura

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20nm-node planar MONOS cell which has improved reliability is developed. Extremely wide program/erase Vth window and good retention characteristics after cycling stress are obtained by buried charge cell structure. Moreover, Vth shift by interference between adjacent cells has smaller dependence on the cell-cell space than Vth window improvement when the(More)
We propose a novel method to extract the imprint of gravitational lensing by Pop III stars in the light curves of Gamma Ray Bursts (GRBs). Significant portions of GRBs can originate in hypernovae of Pop III stars and be gravitationally lensed by foreground Pop III stars or their remnants. If the lens mass is on the order of 10 − 10M⊙ and the lens redshift(More)
We explore the formation of dusty gas walls induced by a circumnuclear starburst around an active galactic nucleus (AGN). We concentrate our attention on the role of the radiation force by a starburst as well as an AGN, where the effects of optical depth of dusty gas are taken into consideration. First, we solve the hydrostatic equations in spherical(More)
By solving radiative transfer equations, we examine three-dimensional radiative properties of a magnetohydrodynamic accretion flow model confronting with the observed spectrum of Sgr A*, in the vicinity of supermassive black hole at the Galactic centre. As a result, we find that the core of radio emission is larger than the size of the event horizon shadow(More)
To elucidate the effects of the UV background radiation on the collapse of pregalactic clouds, we implement a radiation-hydrodynamical calculation, combining onedimensional spherical hydrodynamics with an accurate treatment of the radiative transfer of ionizing photons. Both absorption and scattering of UV photons are explicitly taken into account. It turns(More)
We consider the radiation-hydrodynamical formation of a dusty wall in the circumnuclear regions of the Circinus Seyfert 2 galaxy. We focus on the radiative flux force due to the circumnuclear starburst, the nuclear starburst and the active galactic nucleus (AGN), and analyze the equilibrium configuration and stability of the dusty gas in the circumnuclear(More)
Feedback provided by relativistic jets may be effective in shaping the galaxy luminosity function. The quenching mode (quasar mode) at redshifts ∼2-3 potentially disperses gas in star-forming galaxies. The maintenance mode (radio mode) heats the gas in galaxy clusters counteracting cooling flows. A number of authors have examined the effect of relativistic(More)
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