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 30.5ks and 34.4ks, respectively. In the 2005 ...and 2006 observations, the source was detected at an average 10-30keV intensity of 290mCrab and 230mCrab, respectively. The intrinsic pulse period was measured on both occasions at 1.23776s by HXD-PIN, after barycentric and binary corrections. The pulse phase-averaged spectra in the energy range above 10keV were well fitted by the “Negative and Positive power-law times EXponential” (NPEX) model, multiplied by a fundamental cyclotron resonance scattering feature at
$\sim$
36keV, which appears very significantly in the HXD-PIN data. The resonance profiles were successfully reproduced by a Lorentzian-type scattering cross section, rather than by a Gaussian-type alternative. The pulse phase-averaged HXD-GSO data, covering 50-120keV, are featureless. However, in a differential spectrum between the pulse-decay phase and off-pulse phase, the second-harmonic cyclotron resonance was detected in the GSO data at
$\sim$
73keV, with a depth of 1.6
$_{-0.7}^{+0.9}$
. This makes Her X-1 a 6th pulsar with established second-harmonic resonance. The implications of these results are briefly discussed.
Suzaku Wide-Band Observations of SN 1006 Bamba, Aya; Fukazawa, Yasushi; Hiraga, Junko S ...
Publications of the Astronomical Society of Japan,
02/2008, Letnik:
60, Številka:
sp1
Journal Article
Recenzirano
Odprti dostop
We report on the wide-band spectra of SN1006, as observed by Suzaku. Thermal and nonthermal emissions were successfully resolved thanks to the excellent spectral response of Suzaku's X-ray CCD XIS. ...The nonthermal emission could not be reproduced by a simple power-law model, but needed a roll-off at 5.7
$\times$
10
$^{16}$
Hz
$=$
0.23keV. The roll-off frequency is significantly higher in the northeastern rim than in the southwestern rim. We also placed the most stringent upper limit of the flux above 10keV using the Hard X-ray Detector.
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