Search Publications
Interacting Cosmic Rays with Molecular Clouds: A Bremsstrahlung Origin of Diffuse High-energy Emission from the Inner 2°×1° of the Galactic Center
Hewitt, J. W.; Nobukawa, M.; Tsuru, T. G. +8 more
The high-energy activity in the inner few degrees of the Galactic center is traced by diffuse radio, X-ray, and γ-ray emission. The physical relationship between different components of diffuse gas emitting at multiple wavelengths is a focus of this work. We first present radio continuum observations using the Green Bank Telescope and model the no…
Suzaku Observations of the Diffuse X-Ray Emission across the Fermi Bubbles' Edges
Cheung, C. C.; Kataoka, J.; Stawarz, Ł. +10 more
We present Suzaku X-ray observations along two edge regions of the Fermi Bubbles, with eight ~= 20 ks pointings across the northern part of the North Polar Spur (NPS) surrounding the north bubble and six across the southernmost edge of the south bubble. After removing compact X-ray features, diffuse X-ray emission is clearly detected and is well r…
An X-Ray View of the Jet Cycle in the Radio-loud AGN 3C120
Miller, Eric D.; Fabian, Andrew C.; Brenneman, Laura W. +10 more
We present a study of the central engine in the broad-line radio galaxy 3C120 using a multi-epoch analysis of a deep XMM-Newton observation and two deep Suzaku pointings (in 2012). In order to place our spectral data into the context of the disk-disruption/jet-ejection cycles displayed by this object, we monitor the source in the UV/X-ray bands, a…
Thermodynamics of the Coma Cluster Outskirts
Simionescu, A.; Fabian, A. C.; Allen, S. W. +10 more
We present results from a large mosaic of Suzaku observations of the Coma Cluster, the nearest and X-ray brightest hot (~8 keV), dynamically active, non-cool core system, focusing on the thermodynamic properties of the intracluster medium on large scales. For azimuths not aligned with an infalling subcluster toward the southwest, our measured temp…
The Smooth Cyclotron Line in Her X-1 as Seen with Nuclear Spectroscopic Telescope Array
Hailey, Charles J.; Fürst, Felix; Klochkov, Dmitry +17 more
Her X-1, one of the brightest and best studied X-ray binaries, shows a cyclotron resonant scattering feature (CRSF) near 37 keV. This makes it an ideal target for a detailed study with the Nuclear Spectroscopic Telescope Array (NuSTAR), taking advantage of its excellent hard X-ray spectral resolution. We observed Her X-1 three times, coordinated w…
Discovery of the Recombining Plasma in the South of the Galactic Center: A Relic of the Past Galactic Center Activity?
Koyama, K.; Tanaka, T.; Murakami, H. +5 more
We report Suzaku results for soft X-ray emission to the south of the Galactic center (GC). The emission (hereafter "GC South") has an angular size of ~42' × 16' centered at (l, b) ~ (0.°0, - 1.°4) and is located in the largely extended Galactic ridge X-ray emission (GRXE). The X-ray spectrum of GC South exhibits emission lines from highly ionized …
Discovery of GeV Emission from the Circinus Galaxy with the Fermi Large Area Telescope
Stawarz, Łukasz; Madejski, Greg M.; Cheung, Chi C. +7 more
We report the discovery of γ-ray emission from the Circinus galaxy using the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. Circinus is a nearby (~4 Mpc) starburst with a heavily obscured Seyfert-type active nucleus, bipolar radio lobes perpendicular to the spiral disk, and kpc-scale jet-like structures. Our analysis of 0…
Suzaku Observations of the Outskirts of A1835: Deviation from Hydrostatic Equilibrium
Zhang, Y. -Y.; Finoguenov, A.; Sato, Kosuke +12 more
We present results of four-pointing Suzaku X-ray observations (total ~200 ks) of the intracluster medium (ICM) in the A1835 galaxy cluster (kT ~ 8 keV, z = 0.253) out to the virial radius (r vir ~ 2.9 Mpc) and beyond. Faint X-ray emission from the ICM out to r vir is detected. The temperature gradually decreases with radius f…
X-Ray Outflows and Super-Eddington Accretion in the Ultraluminous X-Ray Source Holmberg IX X-1
Harrison, F. A.; Fabian, A. C.; Miller, J. M. +4 more
Studies of X-ray continuum emission and flux variability have not conclusively revealed the nature of ultraluminous X-ray sources (ULXs) at the high-luminosity end of the distribution (those with L X >= 1040 erg s-1). These are of particular interest because the luminosity requires either super-Eddington accreti…
A Super-solar Metallicity for the Progenitor of Kepler's Supernova
Hughes, John P.; Lee, Jae-Joon; Mori, Koji +8 more
We have performed deep X-ray observations of the remnant of Kepler's supernova (SN 1604) as a Key Project of the Suzaku Observatory. Our main goal is to detect secondary Fe-peak elements in the supernova (SN) ejecta to gain insights into the Type Ia SN explosion mechanism and the nature of the progenitor. Here, we report our initial results. We ma…