Search Publications
The Spin of the Supermassive Black Hole in NGC 3783
Nandra, K.; Iwasawa, K.; Fabian, A. C. +9 more
The Suzaku AGN Spin Survey is designed to determine the supermassive black hole spin in six nearby active galactic nuclei (AGNs) via deep Suzaku stares, thereby giving us our first glimpse of the local black hole spin distribution. Here, we present an analysis of the first target to be studied under the auspices of this Key Project, the Seyfert ga…
Gas Clumping in the Outskirts of ΛCDM Clusters
Nagai, Daisuke; Lau, Erwin T.
Recent Suzaku X-ray observations revealed that the observed entropy profile of the intracluster medium (ICM) deviates significantly from the prediction of hydrodynamical simulations of galaxy clusters. In this work, we show that gas clumping introduces significant biases in X-ray measurements of the ICM profiles in the outskirts of galaxy clusters…
Corona, Jet, and Relativistic Line Models for Suzaku/RXTE/Chandra-HETG Observations of the Cygnus X-1 Hard State
Pottschmidt, Katja; Wilms, Jörn; Tramper, Frank +7 more
Using Suzaku and the Rossi X-ray Timing Explorer (RXTE), we have conducted a series of four simultaneous observations of the galactic black hole candidate Cyg X-1 in what were historically faint and spectrally hard "low states." Additionally, all of these observations occurred near superior conjunction with our line of sight to the X-ray source pa…
Fe-K Line Probing of Material Around the Active Galactic Nucleus Central Engine with Suzaku
Fukazawa, Yasushi; Ohno, Masanori; Nishino, Sho +6 more
We systematically analyzed the high-quality Suzaku data of 88 Seyfert galaxies, about 31% of which are Compton-thick active galactic nuclei (AGNs). We obtained a clear relation between the absorption column density and the equivalent width (EW) of the 6.4 keV line above 1023 cm-2, suggesting a wide-ranging column density of 1…
Possible Charge-exchange X-ray Emission in the Cygnus Loop Detected with Suzaku
Katsuda, Satoru; Petre, Robert; Yamaguchi, Hiroya +8 more
X-ray spectroscopic measurements of the Cygnus Loop supernova remnant indicate that metal abundances throughout most of the remnant's rim are depleted to ~0.2 times the solar value. However, recent X-ray studies have revealed in some narrow regions along the outermost rim anomalously "enhanced" abundances (up to ~1 solar). The reason for these ano…
A Census of Baryons and Dark Matter in an Isolated, Milky Way Sized Elliptical Galaxy
Fabian, Andrew C.; Canizares, Claude R.; Humphrey, Philip J. +2 more
We present a study of the dark and luminous matter in the isolated elliptical galaxy NGC 720, based on deep X-ray observations made with the Chandra and Suzaku observatories. The gas properties are reliably measured almost to R 2500, allowing us to place good constraints on the enclosed mass and baryon fraction (fb ) within t…
X-Ray Spectral Constraints for z ≈ 2 Massive Galaxies: The Identification of Reflection-dominated Active Galactic Nuclei
Daddi, E.; Lehmer, B. D.; Alexander, D. M. +18 more
We use the 4 Ms Chandra Deep Field-South (CDF-S) survey to place direct constraints on the ubiquity of z ≈ 2 heavily obscured active galactic nuclei (AGNs) in K < 22 BzK-selected galaxies. Forty-seven (≈21%) of the 222 BzK-selected galaxies in the central region of the CDF-S are detected at X-ray energies, 11 (≈5%) of which have hard X-ray spec…
X-Ray Spectroscopy of the High-mass X-Ray Binary Pulsar Centaurus X-3 over Its Binary Orbit
Paul, Biswajit; Naik, Sachindra; Ali, Zulfikar
We present a comprehensive spectral analysis of the high-mass X-ray binary (HMXB) pulsar Centaurus X-3 with the Suzaku observatory covering nearly one orbital period. The light curve shows the presence of extended dips which are rarely seen in HMXBs. These dips are seen up to as high as ~40 keV. The pulsar spectra during the eclipse, out-of-eclips…
New Evidence for High Activity of the Supermassive Black Hole in our Galaxy
Koyama, K.; Nobukawa, M.; Tsuru, T. G. +1 more
Prominent K-shell emission lines of neutral iron (hereafter Fe I-K lines) and hard-continuum X-rays from molecular clouds (MCs) in the Sagittarius B (Sgr B) region were found in two separate Suzaku observations in 2005 and 2009. The X-ray flux of the Fe I-K lines decreased in correlation with the hard-continuum flux by a factor of 0.4-0.5 in four …
A Study of the X-rayed Outflow of APM 08279+5255 through Photoionization Codes
Chartas, George; Saez, Cristian
We present new results from our study of the X-rayed outflow of the z = 3.91 gravitationally lensed broad absorption line quasar APM 08279+5255. These results are based on spectral fits to all the long exposure observations of APM 08279+5255 using a new quasar-outflow model. This model is based on CLOUDY 3 CLOUDY is a photoionization co…