Publications of the Astronomical Society of Japan 62(2) 1-11 Apr 2010 [Refereed]
The fastest-rotating magnetar 1E 1547.0-5408 was observed in broad-band
X-rays with Suzaku for 33 ks on 2009 January 28-29, 7 days after the onset of
its latest bursting activity. After removing burst events, the
absorption-uncorrected 2-10 keV flux of the persistent emission was measured
with the XIS as 5.7e-11 ergs cm-2 s-1, which is 1-2 orders of magnitude higher
than was measured in 2006 an...
T. Enoto, Y. E. Nakagawa, N. Rea, P. Esposito, D. Gotz, K. Hurley, G. L. Israel, M. Kokubun, K. Makishima, S. Mereghetti, H. Murakami, K. Nakazawa, T. Sakamoto, L. Stella, A. Tiengo, R. Turolla, S. Yamada, K. Yamaoka, A. Yoshida, S. Zane
The Astrophysical Journal Letters 693(2) 122-126 Jan 2009 [Refereed]
We present the first Suzaku observation of the new Soft Gamma Repeater SGR
0501+4516, performed on 2008 August 26, four days after the onset of bursting
activity of this new member of the magnetar family. The soft X-ray persistent
emission was detected with the X-ray Imaging Spectrometer (XIS) at a 0.5-10 keV
flux of 3.8E-11 erg/s/cm2, with a spectrum well fitted by an absorbed blackbody
plus p...
Publications of the Astronomical Society of Japan 61(SP1) S17-S33 Aug 2007 [Refereed]
The accretion-powered pulsar Her X-1 was observed with Suzaku twice in its main-on state, on 2005 October 5-6 and 2006 March 29-30, for a net exposure of 30.5 ks and 34.4 ks, respectively. In the 2005 and 2006 observations, the source was detected at an average 10-30 keV intensity of 290 mCrab and 230 mCrab, respectively. The intrinsic pulse period was measured on both occasions at 1.23776 s by...
H. Tsuchiya, T. Enoto, S. Yamada, T. Yuasa, M. Kawaharada, T. Kitaguchi, M. Kokubun, H. Kato, M. Okano, S. Nakamura, K. Makishima
Phys.Rev.Lett.99:165002,2007 Aug 2007
A report is made on a comprehensive observation of a burst-like -ray
emission from thunderclouds on the Sea of Japan, during strong thunderstorms on
2007 January 6. The detected emission, lasting for 40 seconds, preceded
cloud-to-ground lightning discharges. The burst spectrum, extending to 10 MeV,
can be interpreted as consisting of bremsstrahlung photons originating from
relativ...
H. Tsuchiya, T. Enoto, T. Torii, K. Nakazawa, T. Yuasa, S. Torii, T. Fukuyama, T. Yamaguchi, H. Kato, M. Okano, M. Takita, K. Makishima
Phys. Rev. Lett. 102, 255003 (2009) Jun 2009
During thunderstorms on 2008 September 20, a simultaneous detection of gamma
rays and electrons was made at a mountain observatory in Japan located 2770 m
above sea level. Both emissions, lasting 90 seconds, were associated with
thunderclouds rather than lightning. The photon spectrum, extending to 10 MeV,
can be interpreted as consisting of bremsstrahlung gamma rays arriving from a
source whic...
The hard X-ray detector (HXD) on board the X-ray satellite Suzaku is designed
to have a good timing capability with a 61 s time resolution. In addition
to detailed descriptions of the HXD timing system, results of in-orbit timing
calibration and performance of the HXD are summarized. The relative accuracy of
time measurements of the HXD event was confirmed to have an accuracy of
$1.9\times...
M. Kokubun, K. Makishima, T. Takahashi, T. Murakami, M. Tashiro, Y. Fukazawa, T. Kamae, G. M. Madejski, K. Nakazawa, K. Yamaoka, Y. Terada, D. Yonetoku, S. Watanabe, T. Tamagawa, T. Mizuno, A. Kubota, N. Isobe, I. Takahashi, G. Sato, H. Takahashi, S. Hong, M. Kawaharada, N. Kawano, T. Mitani, M. Murashima, M. Suzuki, K. Abe, R. Miyawaki, M. Ohno, T. Tanaka, T. Yanagida, T. Itoh, K. Ohnuki, K. Tamura, Y. Endo, S. Hirakuri, T. Hiruta, T. Kitaguchi, T. Kishishita, S. Sugita, T. Takahashi, S. Takeda, T. Enoto, A. Hirasawa, J. Katsuta, S. Matsumura, K. Onda, M. Sato, M. Ushio, S. Ishikawa, K. Murase, H. Odaka, M. Suzuki, Y. Yaji, S. Yamada, T. Yamasaki, T. Yuasa
Publ.Astron.Soc.Jap.59:53-76,2007 Nov 2006
The in-orbit performance and calibration of the Hard X-ray Detector (HXD) on
board the X-ray astronomy satellite Suzaku are described. Its basic
performances, including a wide energy bandpass of 10-600 keV, energy
resolutions of ~4 keV (FWHM) at 40 keV and ~11% at 511 keV, and a high
background rejection efficiency, have been confirmed by extensive in-orbit
calibrations. The long-term gains of ...
Y. Terada, T. Mihara, M. Nakajima, M. Suzuki, N. Isobe, K. Makishima, H. Takahashi, T. Enoto, M. Kokubun, T. Kitaguchi, S. Naik, T. Dotani, F. Nagase, T. Tanaka, S. Watanabe, S. Kitamoto, K. Sudoh, A. Yoshida, Y. Nakagawa, S. Sugita, T. Kohmura, T. Kotani, D. Yonetoku, L. Angelini, J. Cottam, K. Mukai, R. Kelley, Y. Soong, M. Bautz, S. Kissel, J. Doty
Astrophys.J. 648 (2006) L139-L142 Jul 2006
The binary X-ray pulsar A0535+262 was observed with the Suzaku X-ray
observatory, on 2005 September 14 for a net exposure of 22 ksec. The source was
in a declining phase of a minor outburst, exhibiting 3--50 keV luminosity of
about ergs s at an assumed distance of 2 kpc. In
spite of the very low source intensity (about 30 mCrab at 20 keV), its electron
cyclotron reso...
S. Naik, T. Dotani, Y. Terada, M. Nakajima, T. Mihara, M. Suzuki, K. Makishima, K. Sudoh, S. Kitamoto, F. Nagase, T. Enoto, H. Takahashi
2008, The Astrophysical Journal, 672, 516 Oct 2007
The transient X-ray binary pulsar A0535+262 was observed with Suzaku on 2005
September 14 when the source was in the declining phase of the August-September
minor outburst. The ~103 s X-ray pulse profile was strongly energy dependent, a
double peaked profile at soft X-ray energy band (<3 keV) and a single peaked
smooth profile at hard X-rays. The width of the primary dip is found to be
incre...
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 window option to achieve a time
resolution of 1 s. Pulsations are clearly detected in the XIS light curves with
a barycenter corrected pulse period of 10.61063(2) s. The XIS pulse profile
shows 3 peak...
