Takanori Sakamoto

The Correlation of Spectral Lag Evolution with Prompt Optical Emission in GRB 080319B (2009)

Stamatikos, Michael, Ukwatta, Tilan N., Sakamoto, Takanori, Dhuga, Kalvir S., Toma, Kenji, Pe'er, Asaf, ...

We report on observations of correlated behavior between the prompt gamma-ray and optical emission from GRB 080319B, which confirm that (i) they occurred within the same astrophysical source region...

Statistical Properties of Gamma-Ray Burst Polarization (2008)

Toma, Kenji, Sakamoto, Takanori, Zhang, Bing, Hill, Joanne E., McConnell, Mark L., Bloser, Peter F., ...

The emission mechanism and the origin and structure of magnetic fields in gamma-ray burst (GRB) jets are among the most important open questions concerning the nature of the central engine of GRBs....

Correlative Spectral Analysis of Gamma-Ray Bursts using Swift-BAT and GLAST-GBM (2008)

Stamatikos, Michael, Sakamoto, Takanori, Band, David L.

We discuss the preliminary results of spectral analysis simulations involving anticipated correlated multi-wavelength observations of gamma-ray bursts (GRBs) using Swift's Burst Alert Telescope (BAT)...

A Correlation of Spectral Lag Evolution with Prompt Optical Emission in GRBs? (2008)

Stamatikos, Michael, Ukwatta, Tilan N., Sakamoto, Takanori, Dhuga, Kalvir S.

We report on observations of correlated behavior between the prompt gamma-ray and optical emission from GRB 080319B, which (i) strongly suggest that they occurred within the same astrophysical source...

Multiple Component Analysis of Time Resolved Spectra of GRB041006: A Clue to the Nature of Underlying Soft Component of GRBs (2008)

Shirasaki, Yuji, Yoshida, Atsumasa, Kawai, Nobuyuki, Tamagawa, Toru, Sakamoto, Takanori, Suzuki, Motoko, ...

GRB 041006 was detected by HETE-2 at 12:18:08 UT on 06 October 2004. This GRB displays a soft X-ray emission, a precursor before the onset of the main event, and also a soft X-ray tail after the end...

Spectral Properties of Prompt Emission of Four Short Gamma-Ray Bursts Observed by the Suzaku-WAM and the Konus-Wind (2008)

Ohno, Masanori, Fukazawa, Yasushi, Takahashi, Takuya, Yamaoka, Kazutaka, Sugita, Satoshi, Pal'shin, Valentin, ...

We have performed a joint analysis of prompt emission from four bright short gamma-ray bursts (GRBs) with the Suzaku-WAM and the Konus-Wind experiments. This joint analysis allows us to investigate...

Testing the External Shock Model of Gamma-Ray Bursts using the Late-Time Simultaneous Optical and X-ray Afterglows (2007)

Urata, Yuji, Yamazaki, Ryo, Sakamoto, Takanori, Huang, Kuiyun, Zheng, Weikang, Sato, Goro, ...

We study the ``normal'' decay phase of the X-ray afterglows of gamma-ray bursts (GRBs), which follows the shallow decay phase, using the events simultaneously observed in the R-band. The classical...

Probing the Structure of Gamma-Ray Burst Jets with Steep Decay Phase of their Early X-ray Afterglows (2007)

Takami, Kentaro, Yamazaki, Ryo, Sakamoto, Takanori, Sato, Goro

We show that the jet structure of gamma-ray bursts (GRBs) can be investigated with the tail emission of the prompt GRB. The tail emission which we consider is identified as a steep-decay component of...

HETE-2 Observations of the X-Ray Flash XRF 040916 (2007)

Arimoto, Makoto, Kawai, Nobuyuki, Yoshida, Atsumasa, Tamagawa, Toru, Shirasaki, Yuji, Suzuki, Motoko, ...

A long X-ray flash was detected and localized by the instruments aboard the High Energy Transient Explorer II (HETE-2) at 00:03:30 UT on 2004 September 16. The position was reported to the GRB...

Lie Algebras Represented as a Sum of Two Subalgebras (2006)

Honda, Masanobu, Sakamoto, Takanori

Let L be a Lie algebra represented as a sum of two subalgebras A and B. We prove that if L belongs to a subclass of the class of locally finite Lie algebras over a field of characteristic ≠ 2 and...

Swift and XMM-Newton Observations of the Extraordinary GRB 060729: An afterglow with a more than 100 days X-ray light curve (2006)

Grupe, Dirk, Gronwall, Caryl, Wang, Xiang-Yu, Roming, Peter, Cummings, Jay, Zhang, Bing, ...

We report the results of the Swift and XMM observations of the Swift-discovered long Gamma-Ray Burst GRB 060729 ($T_{90}$=115s). The afterglow of this burst was exceptionally bright in X-rays as well...

Low-Luminosity GRB 060218: A Collapsar Jet from a Neutron Star, Leaving a Magnetar as a Remnant? (2006)

Toma, Kenji, Ioka, Kunihito, Sakamoto, Takanori, Nakamura, Takashi

The gamma-ray burst (GRB) 060218 has ~ 10^5 times lower luminosity than typical long GRBs, and is associated with a supernova (SN). The radio afterglow displays no jet break, so that this burst might...

GRB Radiative Efficiencies Derived from the Swift Data: GRBs vs. XRFs, Long vs. Short (2006)

Zhang, Bing, Liang, Enwei, Page, Kim L., Grupe, Dirk, Zhang, Bin-Bin, Barthelmy, Scott D., ...

We systematically analyze the prompt emission and the early afterglow data of a sample of 31 GRBs detected by {\em Swift} before September 2005, and estimate the GRB radiative efficiency. BAT's...

The Swift X-ray flaring afterglow of GRB 050607 (2006)

Pagani, Claudio, Morris, David C., Kobayashi, Shiho, Sakamoto, Takanori, Falcone, Abraham D., Moretti, Alberto, ...

The definitive version of this paper is available at http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v645n2/64323/64323.html

An Optically Dark GRB Observed by HETE-2: GRB 051022 (2006)

Nakagawa, Yujin E., Yoshida, Atsumasa, Sugita, Satoshi, Tanaka, Kaoru, Ishikawa, Nobuyuki, Tamagawa, Toru, ...

GRB 051022 was detected at 13:07:58 on 22 October 2005 by HETE-2. The location of GRB 051022 was determined immediately by the flight localization system. This burst contains multiple pulses and has...

GRB 060313: A New Paradigm for Short-Hard Bursts? (2006)

Roming, Peter W. A., Berk, Daniel Vanden, Palshin, Valentin, Pagani, Claudio, Norris, Jay, Kumar, Pawan, ...

We report the simultaneous observations of the prompt emission in the gamma-ray and hard X-ray bands by the Swift-BAT and the KONUS-Wind instruments of the short-hard burst, GRB 060313. The...

The Swift X-ray flaring afterglow of GRB 050607 (2006)

Pagani, Claudio, Morris, David C., Kobayashi, Shiho, Sakamoto, Takanori, Falcone, Abraham D., Moretti, Alberto, ...

The unique capability of the Swift satellite to perform a prompt and autonomous slew to a newly detected Gamma-Ray Burst (GRB) has yielded the discovery of interesting new properties of GRB X-ray...

The shock break-out of GRB060218/SN2006aj (2006)

Campana, Sergio, Mangano, V., Blustin, A.J., Brown, P., Burrows, David N., Chincarini, Guido, ...

This is a preprint, as archived in arXiv.org, of the paper subsequently published as Nature, 2006, 442, pp.1008-1010 and available from...

Amino Acids Dissolved in Stream Water as Possible Home Stream Odorants for Masu Salmon (2000)

Shoji, Takayuki, Ueda, Hiroshi, Ohgami, Toshio, Sakamoto, Takanori, Katsuragi, Yoshihisa, Yamauchi, Kohei, ...

It is well established that salmon return to their home stream by sensing the odors of the stream water. In this study we have attempted to identify the home stream odorants used by masu salmon in...

Redistribution of {alpha}-Granule Membrane Glycoprotein IIb/IIIa (Integrin {alpha}IIb{beta}3) to the Surface Membrane of Human Platelets during the Release Reaction (1994)

Suzuki, Hidenori, Kaneko, Takamasa, Sakamoto, Takanori, Nakagawa, Mine, Miyamoto, Takuji, Yamada, Mitsuhiko, ...

Treatment of human washed platelets with 5 mM EDTA at 37° for 60 min irreversibly dissociated glycoprotein (GP) IIb/IIIa complex (αIIbβ3 integrin) on the surface membrane, since transmission...

Intraoperative Electrophysiologic Monitoring of Ocular Motor Nerves Under Conditions of Partial Neuromuscular Blockade During Skull Base Surgery

Kawaguchi, Masahiko, Ohnishi, Hideyuki, Sakamoto, Takanori, Shimizu, Kiyoshi, Karasawa, Jun, Furuya, Hitoshi

The feasibility and usefulness of intraoperative electromyographic monitoring of the oculomotor nerve (CN III), trochlear nerve (CN IV), and abducens nerve (CN IV) were evaluated under conditions of...

Intraoperative Electrophysiologic Monitoring of Ocular Motor Nerves Under Conditions of Partial Neuromuscular Blockade During Skull Base Surgery

Kawaguchi, Masahiko, Ohnishi, Hideyuki, Sakamoto, Takanori, Shimizu, Kiyoshi, Karasawa, Jun, Furuya, Hitoshi

The feasibility and usefulness of intraoperative electromyographic monitoring of the oculomotor nerve (CN III), trochlear nerve (CN IV), and abducens nerve (CN IV) were evaluated under conditions of...