Search Publications
``Comets'' orbiting a black hole
Maiolino, R.; Elvis, M.; Fabbiano, G. +6 more
We use a long (300 ks), continuous Suzaku X-ray observation of the active nucleus in NGC 1365 to investigate the structure of the circumnuclear broad line region (BLR) clouds through their occultation of the X-ray source. The variations of the absorbing column density and of the covering factor indicate that the clouds surrounding the black hole a…
White dwarf masses in intermediate polars observed with the Suzaku satellite
Yamada, S.; Makishima, K.; Ebisawa, K. +5 more
Context. White dwarfs (WDs) in cataclysmic variables (CVs) are important experimental laboratories where the electron degeneracy is taking place on a macroscopic scale. Magnetic CVs increase in number especially in the hard X-ray band (≳ 10 keV) thanks to sensitive hard X-ray missions.
Aims: From X-ray spectroscopy, we estimate the masses of …
XMM-Newton and SUZAKU detection of an X-ray emitting shell around the pulsar wind nebula G54.1+0.3
Bocchino, F.; Bandiera, R.; Gelfand, J.
Context. X-ray observations have proven to be very effective in detecting previously unknown supernova remnant shells around pulsar wind nebulae (PWNe), and in these cases the characteristics of the shell provide information about the evolutionary stage of the embedded PWN. However, it is not clear why some PWNe are “naked”.
Aims: We perform …
Origin of the dust emission from Tycho's SNR
Onaka, T.; Furuzawa, A.; Lee, J. -J. +6 more
Aims: We investigate the spatial distribution of dust emission around Tycho's SNR to understand its origin. We distinguish the dust associated with the SNR from that of the surrounding ISM.
Methods: We performed mid- to far-infrared imaging observations of the remnant at wavelengths of 9, 15, 18, 24, 65, 90, 140, and 160 µm using t…
General relativistic models of the X-ray spectral variability of MCG-6-30-15
Niedźwiecki, A.; Miyakawa, T.
Context. The extremely relativistic Fe lines, detected from some active galactic nuclei (AGN), indicate that generation and reprocessing of the X-ray emission takes place in the immediate vicinity of the event horizon. Recently, general relativistic (GR) effects, in particular light bending which is very strong in that region, have been considered…
The broad-band X-ray spectrum of the Seyfert 1 galaxy, MCG+8-11-11
de Rosa, A.; Bianchi, S.; Piconcelli, E. +5 more
Aims: Evidence is mounting that the main ingredients of the unification models of active galactic nuclei may behave differently from expectations, and be intimately related to fundamental physical parameters. The availability of high signal-to-noise broad-band X-ray spectra provides us with the opportunity to study in detail all the contribut…
The Suzaku broadband X-ray spectrum of the dwarf Seyfert galaxy NGC 4395
Iwasawa, K.; Gallo, L. C.; Tanaka, Y.
We present a Suzaku observation of the dwarf Seyfert galaxy NGC 4395 with an estimated black hole mass of ~105 M⊙. Rapid and strong X-ray variability with an rms amplitude of ~60 per cent is observed in the 0.4-10 keV band with the XIS cameras. The shape of the light curve appears to depend on energies. The hard X-ray emissio…
Suzaku observations of X-ray excess emission in the cluster of galaxies A 3112
Kaastra, J.; Bonamente, M.; Nevalainen, J. +2 more
Aims: We analysed the Suzaku XIS1 data of the A 3112 cluster of galaxies in order to examine the X-ray excess emission in this cluster reported earlier with the XMM-Newton and Chandra satellites.
Methods: We performed X-ray spectroscopy on the data of a single large region. We carried out simulations to estimate the systematic uncertaint…