Toshio Murakami

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...

Gamma-Ray Bursts in $1.8 < z < 5.6$ Suggest that the Time Variation of the Dark Energy is Small (2008)

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...

Suzaku Observation of the Anomalous X-ray Pulsar CXOU J164710.2--455216 (2007)

Naik, Sachindra, Dotani, Tadayasu, Kawai, Nobuyuki, Kokubun, Motohide, Anada, Takayasu, Morii, Mikio, ...

Suzaku TOO observation of the anomalous X-ray pulsar CXOU J164710.2-455216 was performed on 2006 September 23--24 for a net exposure of 38.8 ks. During the observation, the XIS was operated in 1/8...

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...

Spectral evolution of GRB 060904A observed with Swift and Suzaku -- Possibility of Inefficient Electron Acceleration (2007)

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...

Absolute Rate, Evolving Luminosity function, and Evolving Jet Opening Angle Distribution for Long Gamma-Ray Bursts (2005)

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...

A possible observational evidence for $\theta^{-2}$ angular distribution of opening half-angle of GRB jets (2005)

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...

GEOTAIL observation of the SGR1806-20 Giant Flare: The first 600 ms (2005)

Terasawa, Toshio, Tanaka, Yasuyuki, Takei, Yasuhiro, Kawai, Nobuyuki, Yoshida, Atsumasa, Nomoto, Ken'ichi, ...

On December 27, 2004, plasma particle detectors on the GEOTAIL spacecraft detected an extremely strong signal of hard X-ray photons from the giant flare of SGR1806-20, a magnetar candidate. While...

Timing Noise in SGR 1806-20 (2000)

Woods, Peter M., Kouveliotou, Chryssa, Finger, Mark H., Gogus, Ersin, Scott, D. Matthew, Dieters, Stefan, ...

We have phase connected a sequence of RXTE PCA observations of SGR 1806-20 covering 178 days. We find a simple secular spin-down model does not adequately fit the data. The period derivative varies...

Variable Spin-down in the Soft Gamma Repeater SGR 1900+14 and Correlations with Burst Activity (1999)

Woods, Peter M., Kouveliotou, Chryssa, Van Paradijs, Jan, Finger, Mark H., Thompson, Christopher, Duncan, Robert C., ...

We have analyzed Rossi X-ray Timing Explorer Proportional Counter Array observations of the pulsed emission from SGR 1900+14 during September 1996, June - October 1998, and early 1999. Using these...

Sequential Immunization with V3 Peptides from Primary Human Immunodeficiency Virus Type 1 Produces Cross-Neutralizing Antibodies against Primary Isolates with a Matching Narrow-Neutralization Sequence Motif

Eda, Yasuyuki, Takizawa, Mari, Murakami, Toshio, Maeda, Hiroaki, Kimachi, Kazuhiko, Yonemura, Hiroshi, ...

An antibody response capable of neutralizing not only homologous but also heterologous forms of the CXCR4-tropic human immunodeficiency virus type 1 (HIV-1) MNp and CCR5-tropic primary isolate HIV-1...

Anti-V3 Humanized Antibody KD-247 Effectively Suppresses Ex Vivo Generation of Human Immunodeficiency Virus Type 1 and Affords Sterile Protection of Monkeys against a Heterologous Simian/Human Immunodeficiency Virus Infection

Eda, Yasuyuki, Murakami, Toshio, Ami, Yasushi, Nakasone, Tadashi, Takizawa, Mari, Someya, Kenji, ...

In an accompanying report (Y. Eda, M. Takizawa, T. Murakami, H. Maeda, K. Kimachi, H. Yonemura, S. Koyanagi, K. Shiosaki, H. Higuchi, K. Makizumi, T. Nakashima, K. Osatomi, S. Tokiyoshi, S....

Sequential Immunization with V3 Peptides from Primary Human Immunodeficiency Virus Type 1 Produces Cross-Neutralizing Antibodies against Primary Isolates with a Matching Narrow-Neutralization Sequence Motif

Eda, Yasuyuki, Takizawa, Mari, Murakami, Toshio, Maeda, Hiroaki, Kimachi, Kazuhiko, Yonemura, Hiroshi, ...

An antibody response capable of neutralizing not only homologous but also heterologous forms of the CXCR4-tropic human immunodeficiency virus type 1 (HIV-1) MNp and CCR5-tropic primary isolate HIV-1...

Anti-V3 Humanized Antibody KD-247 Effectively Suppresses Ex Vivo Generation of Human Immunodeficiency Virus Type 1 and Affords Sterile Protection of Monkeys against a Heterologous Simian/Human Immunodeficiency Virus Infection

Eda, Yasuyuki, Murakami, Toshio, Ami, Yasushi, Nakasone, Tadashi, Takizawa, Mari, Someya, Kenji, ...

In an accompanying report (Y. Eda, M. Takizawa, T. Murakami, H. Maeda, K. Kimachi, H. Yonemura, S. Koyanagi, K. Shiosaki, H. Higuchi, K. Makizumi, T. Nakashima, K. Osatomi, S. Tokiyoshi, S....

Impact of V2 Mutations on Escape from a Potent Neutralizing Anti-V3 Monoclonal Antibody during In Vitro Selection of a Primary Human Immunodeficiency Virus Type 1 Isolateâ–¿

Shibata, Junji, Yoshimura, Kazuhisa, Honda, Akiko, Koito, Atsushi, Murakami, Toshio, Matsushita, Shuzo

KD-247, a humanized monoclonal antibody to an epitope of gp120-V3 tip, has potent cross-neutralizing activity against subtype B primary human immunodeficiency virus type 1 (HIV-1) isolates. To assess...