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The First Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope
Ozaki, M.; Caraveo, P. A.; D'Elia, V. +205 more
We present the first catalog of active galactic nuclei (AGNs) detected by the Large Area Telescope (LAT), corresponding to 11 months of data collected in scientific operation mode. The First LAT AGN Catalog (1LAC) includes 671 γ-ray sources located at high Galactic latitudes (|b|>10°) that are detected with a test statistic greater than 25 and …
The Fourth IBIS/ISGRI Soft Gamma-ray Survey Catalog
Götz, D.; Hill, A. B.; Rodriguez, J. +19 more
In this paper, we report on the fourth soft gamma-ray source catalog obtained with the IBIS gamma-ray imager on board the INTEGRAL satellite. The scientific data set is based on more than 70 Ms of high-quality observations performed during the first five and a half years of the Core Program and public observations. Compared to previous IBIS survey…
The Palermo Swift-BAT hard X-ray catalogue. III. Results after 54 months of sky survey
Tagliaferri, G.; Cusumano, G.; Sbarufatti, B. +10 more
Aims: We present the Second Palermo Swift-BAT hard X-ray catalogue obtained by analysing data acquired in the first 54 months of the Swift mission.
Methods: Using our software dedicated to the analysis of data from coded mask telescopes, we analysed the BAT survey data in three energy bands (15-30 keV, 15-70 keV, 15-150 keV), obtaining a…
Fading Hard X-ray Emission from the Galactic Center Molecular Cloud Sgr B2
Ponti, G.; Decourchelle, A.; Morris, M. R. +6 more
The center of our Galaxy harbors a four million solar mass black hole that is unusually quiet: its present X-ray luminosity is more than 10 orders of magnitude less than its Eddington luminosity. The observation of iron fluorescence and hard X-ray emission from some of the massive molecular clouds surrounding the Galactic center has been interpret…
The spectral energy distribution of the central parsecs of the nearest AGN
Meisenheimer, K.; Tristram, K. R. W.; Prieto, M. A. +4 more
Spectral energy distributions (SEDs) of the central few tens of parsec region of some of the nearest, most well-studied, active galactic nuclei (AGN) are presented. These genuine AGN-core SEDs, mostly from Seyfert galaxies, are characterized by two main features: an infrared (IR) bump with the maximum in the 2-10µm range and an increasing X-…
The intriguing nature of the high-energy gamma ray source XSS J12270-4859
Mukai, K.; Belloni, T.; de Martino, D. +7 more
Context. The nature of the hard X-ray source XSS J12270-4859 is still unclear. It was claimed to be a possible magnetic cataclysmic variable of the Intermediate Polar type from its optical spectrum and a possible 860 s X-ray periodicity in RXTE data. However, recent observations do not support the latter variability, leaving this X-ray source stil…
Completing the puzzle of the 2004-2005 outburst in V0332+53: the brightening phase included
Tsygankov, S. S.; Lutovinov, A. A.; Serber, A. V.
Analysis of the data obtained with the RXTE observatory during a powerful outburst of the X-ray pulsar V0332+53 in 2004-2005 is presented. Observational data covering the outburst brightening phase are analysed in detail for the first time. A comparison of source parameters and their evolution during the brightening and fading phases shows no evid…
The Palermo Swift-BAT hard X-ray catalogue. II. Results after 39 months of sky survey
Campana, S.; Tagliaferri, G.; Cusumano, G. +12 more
Aims: We present the Palermo Swift-BAT hard X-ray catalogue obtained from the analysis of data acquired during the first 39 months of the Swift mission.
Methods: We developed a dedicated software to perform the data reduction, mosaicking, and source detection of the BAT survey data. We analyzed the BAT dataset in three energy bands (14-1…
INTEGRAL/IBIS 7-year All-Sky Hard X-Ray Survey. II. Catalog of sources
Sunyaev, R.; Krivonos, R.; Tsygankov, S. +3 more
This paper is the second in a series devoted to the hard X-ray (17-60 keV) whole sky survey performed by the INTEGRAL observatory over seven years. Here we present a catalog of detected sources that includes 521 objects, 449 of which exceed a 5σ detection threshold on the time-averaged map of the sky, and 53 were detected in various subsamples of …
X-ray variation statistics and wind clumping in Vela X-1
Klochkov, D.; Wilms, J.; Pottschmidt, K. +8 more
We investigate the structure of the wind in the neutron star X-ray binary system Vela X-1 by analyzing its flaring behavior. Vela X-1 shows constant flaring, with some flares reaching fluxes of more than 3.0 Crab between 20-60 keV for several 100 s, while the average flux is around 250 mCrab. We analyzed all archival INTEGRAL data, calculating the…