Search Publications
Implications of the Warm Corona and Relativistic Reflection Models for the Soft Excess in Mrk 509
Steiner, James F.; Wilms, Jörn; Ricci, Claudio +15 more
We present the analysis of the first Nuclear Spectroscopic Telescope Array observations (∼220 ks), simultaneous with the last Suzaku observations (∼50 ks), of the active galactic nucleus of the bright Seyfert 1 galaxy Mrk 509. The time-averaged spectrum in the 1-79 keV X-ray band is dominated by a power-law continuum (Γ ∼ 1.8-1.9), a strong soft e…
XCLUMPY: X-Ray Spectral Model from Clumpy Torus and Its Application to the Circinus Galaxy
Fukazawa, Yasushi; Tanimoto, Atsushi; Ueda, Yoshihiro +3 more
We construct an X-ray spectral model from the clumpy torus in an active galactic nucleus, designated as “XCLUMPY,” utilizing the Monte Carlo simulation for Astrophysics and Cosmology framework. The adopted geometry of the torus is the same as that in Nenkova et al. who assume a power-law distribution of clumps in the radial direction and a normal …
Kinetic Energy Transfer from X-Ray Ultrafast Outflows to Millimeter/Submillimeter Cold Molecular Outflows in Seyfert Galaxies
Kohno, Kotaro; Mizumoto, Misaki; Izumi, Takuma
UltraFast Outflows (UFOs), seen as X-ray blueshifted absorption lines in active galactic nuclei (AGNs), are considered to be a key mechanism for AGN feedback. In this scenario, UFO kinetic energy is transferred into the cold and extended molecular outflow observed at the millimeter/submillimeter wavelength, which blows away the gas and suppresses …
Spectral and Timing Analysis of the Accretion-powered Pulsar 4U 1626-67 Observed with Suzaku and NuSTAR
Enoto, Teruaki; Chakrabarty, Deepto; Terada, Yukikatsu +13 more
We present an analysis of the spectral shape and pulse profile of the accretion-powered pulsar 4U 1626-67 observed with Suzaku and Nuclear Spectroscopic Telescope Array (NuSTAR) during a spin-up state. The pulsar, which experienced a torque reversal to spin-up in 2008, has a spin period of ∼7.7 s. Comparing the phase-averaged spectra obtained with…
Evidence for a Massive Warm-Hot Circumgalactic Medium around NGC 3221
Nicastro, Fabrizio; Mathur, Smita; Gupta, Anjali +3 more
We report a 3.4σ detection of the warm-hot, massive, extended circumgalactic medium (CGM) around an L ⋆ star-forming spiral galaxy NGC 3221, using deep Suzaku observations. The temperature of the gas is 106.1 K, comparable to that of the Milky Way CGM. The spatial extent of the gas is at least 150 kpc. For a β-model of densit…
Evidence for a Merger-induced Shock Wave in ZwCl 0008.8+5215 with Chandra and Suzaku
Di Gennaro, G.; Brunetti, G.; Forman, W. +8 more
We present the results from new deep Chandra (∼410 ks) and Suzaku (∼180 ks) observations of the merging galaxy cluster ZwCl 0008.8+5215 (z = 0.104). Previous radio observations revealed the presence of a double radio relic located diametrically west and east of the cluster center. Using our new Chandra data, we find evidence for the presence of a …
Testing the Kerr Metric with X-Ray Reflection Spectroscopy of Mrk 335 Suzaku Data
Abdikamalov, Askar B.; Ayzenberg, Dimitry; Bambi, Cosimo +4 more
Einstein’s gravity has undergone extensive tests in the weak field gravitational limit, with results in agreement with theoretical predictions. There exist theories beyond general relativity (GR) which modify gravity in the strong field regime but agree with GR in the weak field. Astrophysical black holes are believed to be described by the Kerr m…
A Hard Look at NGC 5347: Revealing a Nearby Compton-thick AGN
Kaastra, J. S.; Stern, D.; Brandt, W. N. +11 more
Current measurements show that the observed fraction of Compton-thick (CT) active galactic nuclei (AGN) is smaller than the expected values needed to explain the cosmic X-ray background. Prior fits to the X-ray spectrum of the nearby Seyfert-2 galaxy NGC 5347 (z = 0.00792, D = 35.5 Mpc ) have alternately suggested a CT and Compton-thin source. Com…
Developing the Physical Understanding of Intermediate Polars: An X-Ray Study of TV Col and V2731 Oph
Mukai, K.; Lopes de Oliveira, R.
The X-rays in intermediate polars (IPs) originate in a compact region near the surface of a magnetic white dwarf (WD) and interact with the complex environment surrounding the emission region. Here we report a case study of two IPs, TV Col and V2731 Oph, with selected archival X-ray observations (NuSTAR, Swift, Suzaku, and XMM-Newton). For TV Col,…
The Fe Line Flux Ratio as a Diagnostic of the Maximum Temperature and the White Dwarf Mass of Cataclysmic Variables
Xu, Xiao-jie; Yu, Zhuo-li; Li, Xiang-dong
The flux ratio of Fe XXVI-Lyα to Fe XXV-Heα lines (I 7.0/I 6.7) is a sensitive indicator of the maximum temperature (T max), and therefore the mass of white dwarf stars (M WD) in cataclysmic variables (CVs). To examine and calibrate the theoretical I 7.0/I 6.7-T max-M