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Prevalence of High X-ray Obscuring Columns among AGN that Host HO Masers
Lincoln J. Greenhill, Avanti Tilak, Grzegorz Madejski
Of 104 AGN known to exhibit HO maser emission, X-ray data that enable estimation of column densities, or lower limits, are available for 42. Contributing to this, we report ana…
A Deep 0.3-10 keV Spectrum of the HO Maser Galaxy IC 2560
Avanti Tilak, Lincoln Greenhill, Chris Done +1
We present a new XMM-Newton spectrum of the Seyfert 2 nucleus of IC 2560, which hosts HO maser emission from an inclined Keplerian accretion disk. The X-ray spectrum shows so…
PoGOLite - A High Sensitivity Balloon-Borne Soft Gamma-ray Polarimeter
Tuneyoshi Kamae, Viktor Andersson, Makoto Arimoto +36
We describe a new balloon-borne instrument (PoGOLite) capable of detecting 10% polarisation from 200mCrab point-like sources between 25 and 80keV in one 6 hour flight. Polarisation…
Suzaku wide-band X-ray Spectroscopy of the Seyfert 2 AGN in NGC 4945
Takeshi Itoh, Chris Done, Kazuo Makishima +13
Suzaku observed a nearby Seyfert 2 galaxy NGC4945, which hosts one of the brightest active galactic nuclei above 20 keV. Combining data from the X-ray CCD camera (XIS) and the Hard…
The Suzaku Observation of the Nucleus of the Radio-Loud Active Galaxy Centaurus A: Constraints on Abundances of the Accreting Material
A. Markowitz, T. Takahashi, S. Watanabe +16
A Suzaku observation of the nucleus of the radio-loud AGN Centaurus A in 2005 has yielded a broadband spectrum spanning 0.3 to 250 keV. The net exposure times after screening were:…
Application of an XMM-Newton EPIC Monte Carlo Technique to Analysis and Interpretation of Data for the Abell 1689, RX J0658-55 and Centaurus clusters of galaxies
K. E. Andersson, J. R. Peterson, G. M. Madejski
We propose a new Monte Carlo method to study extended X-ray sources with the European Photon Imaging Camera (EPIC) aboard {\sl XMM-Newton}. The smoothed particle inference (SPI) te…
Search for Oxygen Emission from Warm-Hot Intergalactic Medium around A2218 with Suzaku
Yoh Takei, Takaya Ohashi, J. Patrick Henry +12
We searched for redshifted O emission lines from the possible warm-hot intergalactic medium (WHIM) surrounding the cluster of galaxies A2218 at z=0.1756 using the XIS instrument on…
INTEGRAL and RXTE Observations of Centaurus A
Richard E. Rothschild, Joern Wilms, John Tomsick +6
INTEGRAL and RXTE performed three simultaneous observations of the nearby radio galaxy Cen A in 2003 March, 2004 January, and 2004 February with the goals of investigating the geom…
Gamma-ray Polarimetry with Compton Telescope
Hiroyasu Tajima, Grzegorz Madejski, Takefumi Mitani +10
Compton telescope is a promising technology to achieve very high sensitivity in the soft gamma-ray band (0.1-10 MeV) by utilizing Compton kinematics. Compton kinematics also enable…
Performance of a Low Noise Front-end ASIC for Si/CdTe Detectors in Compton Gamma-ray Telescope
H. Tajima, T. Nakamoto, T. Tanaka +11
Compton telescopes based on semiconductor technologies are being developed to explore the gamma-ray universe in an energy band 0.1--20 MeV, which is not well covered by the present…
Complex Structure of Galaxy Cluster Abell 1689: Evidence for a Merger from X-ray data?
K. E. Andersson, G. M. Madejski
Abell 1689 is a galaxy cluster at where previous measurements of its mass using various techniques gave discrepant results. We present a new detailed measurement of the m…
Spectral properties of the Narrow-Line Seyfert 1 Quasar PG1211+143
Agnieszka Janiuk, Bozena Czerny, Grzegorz M. Madejski
We propose a theoretical model to explain the spectrum of the quasar PG1211+143 emitted in the Optical/X-ray bands. In particular, we suggest that the inner accretion disk may deve…
Observation of Cen A by the Rossi X-ray Timing Explorer
R. E. Rothschild, D. L. Band, P. R. Blanco +13
The Rossi X-ray Timing Explorer made a short (10 ks) observation of the radio galaxy Centaurus A on 14 August 1996. Analysis of the combined 2.5-240 keV spectrum has revealed a hea…
Ultraviolet Isotropic Emission from the Blazar 3C 279
E. Pian, A. Koratkar, L. Maraschi +7
Archival IUE SWP and HST FOS spectra show the presence of a relatively strong, broad Lyman alpha emission line superposed onto the UV spectral continuum of the blazar 3C 279. As op…
Multiwavelength Observations of a Dramatic High Energy Flare in the Blazar 3C 279
A. E. Wehrle, E. Pian, C. M. Urry +3
The blazar 3C 279, one of the brightest identified extragalactic objects in the gamma-ray sky, underwent a flare of a factor 10 amplitude in gamma-rays towards the end of a 3-week…
Gamma-ray flux variability in the sample of EGRET blazars
P. Magdziarz, R. Moderski, G. M. Madejski
We analyze average gamma-ray variability statistics for the sample of blazars detected by CGRO/EGRET. We re-reduce all the available EGRET observations and analyze light curves by…