Constraints on $w_0$ and $w_a$ of Dark Energy from High Redshift Gamma Ray Bursts (2008)
Tsutsui, Ryo, Nakamura, Takashi, Yonetoku, Daisuke, Murakami, Toshio, Tanabe, Sachiko, Kodama, Yoshiki, ...
We extend the Hubble diagram up to $z = 5.6$ using 63 gamma-ray bursts (GRBs) via peak energy-peak luminosity relation (so called Yonetoku relation), and obtain constraints on cosmological parameters...
Kodama, Yoshiki, Yonetoku, Daisuke, Murakami, Toshio, Tanabe, Sachiko, Tsutsui, Ryo, Nakamura, Takashi
We calibrated the peak energy-peak luminosity relation of GRBs (so called Yonetoku relation) using 33 events with the redshift $z < 1.62$ without assuming any cosmological models. The luminosity...
In Orbit Timing Calibration of the Hard X-Ray Detector on Board Suzaku (2007)
Terada, Yukikatsu, Enoto, Teruaki, Miyawaki, Ryouhei, Ishisaki, Yoshitaka, Dotani, Tadayasu, Ebisawa, Ken, ...
The hard X-ray detector (HXD) on board the X-ray satellite Suzaku is designed to have a good timing capability with a 61 $\mu$s time resolution. In addition to detailed descriptions of the HXD timing...
Redshift Dependent Lag-Luminosity Relation in 565 BASTE Gamma Ray Bursts (2007)
Tsutsui, Ryo, Nakamura, Takashi, Yonetoku, Daisuke, Murakami, Toshio, Tanabe, Sachiko, Kodama, Yoshiki
We compared redshifts $z_Y$ from Yonetoku relation and $z_{lag}$ from the lag-luminosity relation for 565 BASTE GRBs and were surprised to find that the correlation is very low. Assuming that the...
Yonetoku, Daisuke, Tanabe, Sachiko, Murakami, Toshio, Emura, Naomi, Aoyama, Yuka, Kidamura, Takashi, ...
We observed an X-ray afterglow of GRB 060904A with the Swift and Suzaku satellites. We found rapid spectral softening during both the prompt tail phase and the decline phase of an X-ray flare in the...
The X-ray observatory Suzaku (2007)
Mitsuda, Kazuhisa, Bautz, Mark, Inoue, Hajime, Kelley, Richard L., Koyama, Katsuji, Kunieda, Hideyo, ...
Matsubayashi, Tatsushi, Yamazaki, Ryo, Yonetoku, Daisuke, Murakami, Toshio, Ebisuzaki, Toshikazu
Using the luminosity function and the apparent GRB rate inferred from the spectral peak energy-luminosity relation, we investigate the absolute GRB formation rate, taking into account the effects of...
Yonetoku, Daisuke, Yamazaki, Ryo, Nakamura, Takashi, Murakami, Toshio
We propose a method to estimate the pseudo jet opening half-angle of GRBs using the spectral peak energy ($\Ep$)--peak luminosity relation (so called Yonetoku relation) as well as the...
GRB980425 in the Off-Axis Jet Model of the Standard GRBs (2003)
Yamazaki, Ryo, Yonetoku, Daisuke, Nakamura, Takashi
Using a simple off-axis jet model of GRBs, we can reproduce the observed unusual properties of the prompt emission of GRB980425, such as the extremely low isotropic equivalent gamma-ray energy, the...
An Off-Axis Jet Model For GRB980425 and Low Energy Gamma-Ray Bursts (2003)
Yamazaki, Ryo, Yonetoku, Daisuke, Nakamura, Takashi
Using a simple off-axis jet model of GRBs, we can reproduce the observed unusual properties of the prompt emission of GRB980425, such as the extremely low isotropic equivalent gamma-ray energy, the...