Search Publications
A Compton-thick Wind in the High-luminosity Quasar, PDS 456
Behar, E.; Turner, T. J.; Fabian, A. C. +7 more
PDS 456 is a nearby (z = 0.184), luminous (L bol ~ 1047 erg s-1) type I quasar. A deep 190 ks Suzaku observation in 2007 February revealed the complex, broadband X-ray spectrum of PDS 456. The Suzaku spectrum exhibits highly statistically significant absorption features near 9 keV in the quasar rest frame. We show …
Broad Relativistic Iron Emission Line Observed in SAX J1808.4-3658
Altamirano, D.; Wijnands, R.; Miller, J. M. +4 more
During the 2008 September-October outburst of the accreting millisecond pulsar SAX J1808.4-3658, the source was observed by both Suzaku and XMM-Newton approximately 1 day apart. Spectral analysis reveals a broad relativistic Fe Kα emission line which is present in both data sets, as has recently been reported for other neutron star low-mass X-ray …
Study on X-Ray Spectra of Obscured Active Galactic Nuclei Based on Monte Carlo Simulation—An Interpretation of Observed Wide-Band Spectra
Terashima, Yuichi; Ikeda, Shinya; Awaki, Hisamitu
Monte Carlo simulation is one of the best tools to study the complex spectra of Compton-thick active galactic nuclei (AGNs) and to figure out the relation between their nuclear structures and X-ray spectra. We have simulated X-ray spectra of Compton-thick AGNs obscured by an accretion torus whose structure is characterized by a half-opening angle,…
How Complex is the Obscuration in Active Galactic Nuclei? New Clues from the Suzaku Monitoring of the X-Ray Absorbers in NGC 7582
Fiore, Fabrizio; Bianchi, Stefano; Piconcelli, Enrico +3 more
We present the results of a Suzaku monitoring campaign of the Seyfert 2 galaxy, NGC 7582. The source is characterized by very rapid (on timescales even lower than a day) changes of the column density of an inner absorber, together with the presence of constant components arising as reprocessing from a Compton-thick material. The best-fitting scena…
Discovery of Strong Radiative Recombination Continua from the Supernova Remnant IC 443 with Suzaku
Yamaguchi, H.; Ozawa, M.; Koyama, K. +4 more
We present the Suzaku spectroscopic study of the Galactic middle-aged supernova remnant (SNR) IC 443. The X-ray spectrum in the 1.75-6.0 keV band is described by an optically thin thermal plasma with the electron temperature of ~0.6 keV and several additional Lyman lines. We robustly detect, for the first time, strong radiative recombination conti…
Suzaku Discovery of the Strong Radiative Recombination Continuum of Iron from the Supernova Remnant W49B
Yamaguchi, H.; Ozawa, M.; Koyama, K. +2 more
We present a hard X-ray spectrum of unprecedented quality of the Galactic supernova remnant (SNR) W49B obtained with the Suzaku satellite. The spectrum exhibits an unusual structure consisting of a saw-edged bump above 8 keV. This bump cannot be explained by any combination of high-temperature plasmas in ionization equilibrium. We firmly conclude …
Truncation of the Inner Accretion Disk Around a Black Hole at Low Luminosity
Kaaret, Philip; Yamaoka, Kazutaka; Kalemci, Emrah +3 more
Most black hole binaries show large changes in X-ray luminosity caused primarily by variations in mass accretion rate. An important question for understanding black hole accretion and jet production is whether the inner edge of the accretion disk recedes at low accretion rate. Measurements of the location of the inner edge (R in) can be…
New Limits on Sterile Neutrinos from Suzaku Observations of the Ursa Minor Dwarf Spheroidal Galaxy
Loewenstein, Michael; Biermann, Peter L.; Kusenko, Alexander
We present results of our search for X-ray line emission associated with the radiative decay of the sterile neutrino, a well motivated dark matter candidate, in Suzaku Observatory spectra of the Ursa Minor dwarf spheroidal galaxy. These data represent the first deep observation of one of these extreme mass-to-light systems and the first dedicated …
Measuring the Spin of GRS 1915+105 with Relativistic Disk Reflection
Fabian, A. C.; Miller, J. M.; Homan, J. +5 more
GRS 1915+105 harbors one of the most massive known stellar black holes in the Galaxy. In 2007 May, we observed GRS 1915+105 for ~117 ks in the low/hard state using Suzaku. We collected and analyzed the data with the Hard X-ray Detector/Positive Intrinsic Negative and X-ray Spectrometer cameras spanning the energy range from 2.3 to 55 keV. Fits to …
Study of the Spectral and Temporal Characteristics of X-Ray Emission of the Gamma-Ray Binary LS 5039 with Suzaku
Yamaoka, Kazutaka; Takahashi, Tadayuki; Uchiyama, Yasunobu +6 more
We report on the results from Suzaku broadband X-ray observations of the galactic binary source LS 5039. The Suzaku data, which have continuous coverage of more than one orbital period, show strong modulation of the X-ray emission at the orbital period of this TeV gamma-ray emitting system. The X-ray emission shows a minimum at orbital phase ~0.1,…