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On the origin of soft X-rays in obscured AGN: answers from high-resolution spectroscopy with XMM-Newton
Guainazzi, Matteo; Bianchi, Stefano
We present results of a high-resolution soft X-ray (0.2-2 keV) spectroscopic study of a sample of 69 nearby obscured active galactic nuclei (AGNs) observed with the reflection grating spectrometer (RGS) onboard XMM-Newton. This is the largest sample ever studied with this technique so far. The main conclusions of our study can be summarized as fol…
Suzaku Observations of the Hard X-Ray Variability of MCG -6-30-15: the Effects of Strong Gravity around a Kerr Black Hole
Fabian, Andrew C.; Kunieda, Hideyo; Haba, Yoshito +21 more
Suzaku has, for the first time, enabled the hard X-ray variability of the Seyfert 1 galaxy MCG -6-30-15 to be measured. The variability in the 14-45keV band, which is dominated by a strong reflection hump, is quenched relative to that at a few keV. This directly demonstrates that the whole reflection spectrum is much less variable than the power-l…
Evidence for Solar-Wind Charge-Exchange X-Ray Emission from the Earth's Magnetosheath
Yamaguchi, Hiroya; Mitsuda, Kazuhisa; Fujimoto, Ryuichi +7 more
We report an apparent detection of the C VI 4p to 1s transition line at 459eV, during a long-term enhancement (LTE) in the Suzaku north ecliptic pole observation of 2005 September 2. The observed line intensity is comparable to that of the C VI 2p to 1s line at 367eV. This is strong evidence for the charge-exchange process. In addition, O VII , O …
The CFHTLS strong lensing legacy survey. I. Survey overview and T0002 release sample
Alard, C.; Gavazzi, R.; Fort, B. +10 more
Aims:We present data from the CFHTLS Strong Lensing Legacy Survey (SL2S). Due to the unsurpassed combined depth, area and image quality of the Canada-France-Hawaii Legacy Survey it is becoming possible to uncover a large, statistically well-defined sample of strong gravitational lenses which spans the dark halo mass spectrum predicted by the conco…
X-ray observations of ultraluminous X-ray sources
Roberts, Timothy P.
Ultraluminous X-ray sources (ULXs) are amongst the most intriguing of X-ray source classes. Their extreme luminosities—greater than 1039 erg s‑1 in the 0.3–10 keV band alone—suggest either the presence of black holes larger than those regularly encountered in our own Galaxy (the Galactic centre excepted), or sources apparentl…
New Distant Companions to Known Nearby Stars. II. Faint Companions of Hipparcos Stars and the Frequency of Wide Binary Systems
Lépine, Sébastien; Bongiorno, Bethany
We perform a search for faint, common proper motion companions of Hipparcos stars using the recently published Lépine-Shara Proper Motion-North catalog of stars with proper motion µ>0.15'' yr-1. Our survey uncovers a total of 521 systems with angular separations 3''<Δθ<1500'', with 15 trip…
Probing the Dark Matter and Gas Fraction in Relaxed Galaxy Groups with X-Ray Observations from Chandra and XMM-Newton
Humphrey, Philip J.; Buote, David A.; Brighenti, Fabrizio +4 more
We present radial mass profiles within ~0.3rvir for 16 relaxed galaxy groups-poor clusters (kT range 1-3 keV) selected for optimal mass constraints from the Chandra and XMM-Newton data archives. After accounting for the mass of hot gas, the resulting mass profiles are described well by a two-component model consisting of dark matter, re…
Discovery of a Ringlike Dark Matter Structure in the Core of the Galaxy Cluster Cl 0024+17
Ford, H. C.; Demarco, R.; van der Wel, A. +13 more
We present a comprehensive mass reconstruction of the rich galaxy cluster Cl 0024+17 at z~=0.4 from ACS data, unifying both strong- and weak-lensing constraints. The weak-lensing signal from a dense distribution of background galaxies (~120 arcmin-2) across the cluster enables the derivation of a high-resolution parameter-free mass map.…
Six new candidate ultracompact X-ray binaries
in't Zand, J. J. M.; Jonker, P. G.; Markwardt, C. B.
Ultracompact X-ray binaries (UCXBs) appear able to sustain accretion onto the compact accretor at rates lower than in wider X-ray binaries. This may be understood by the smaller accretion disks in UCXBs: a lower X-ray luminosity suffices to keep a disk completely ionized through irradiation and, thus, keep the viscosity at a sufficiently high leve…
Ultralow frequency modulation of energetic particles in the dayside magnetosphere
Balogh, A.; Zong, Q. -G.; Baker, D. N. +8 more
Energetic electron and ion (electrons: 30 keV to 500 keV, protons: 30 keV to 1.5 MeV) flux variations associated with ultralow frequency (ULF) waves in the dayside magnetosphere were observed during the CLUSTER's perigee pass near 0900 MLT on Oct. 31, 2003. The ULF modulation terminated where higher frequency fluctuations appeared, as the CLUSTER …