Search Publications
Extreme flux states of NGC 4151 observed with INTEGRAL
Paltani, S.; Walter, R.; Ferrigno, C. +5 more
We present a comprehensive spectral analysis of all INTEGRAL data obtained so far for the X-ray-bright Seyfert galaxy NGC 4151. We also use all contemporaneous data from RXTE, XMM-Newton, Swift and Suzaku. We find a linear correlation between the medium- and hard-energy X-ray fluxes measured by INTEGRAL, which indicates an almost constant spectral…
Hard X-ray properties of magnetic cataclysmic variables
Hill, A. B.; Knigge, C.; Bird, A. J. +10 more
Hard X-ray surveys have proven remarkably efficient in detecting intermediate polars and asynchronous polars, two of the rarest type of cataclysmic variable (CV). Here, we present a global study of hard X-ray-selected intermediate polars and asynchronous polars, focusing particularly on the link between hard X-ray properties and spin/orbital perio…
Deep high-resolution X-ray spectra from cool-core clusters
Fabian, A. C.; Russell, H. R.; Sanders, J. S. +2 more
We examine deep XMM-Newton Reflection Grating Spectrometer (RGS) spectra from the cores of three X-ray bright cool-core galaxy clusters, Abell 262, Abell 3581 and HCG 62. Each of the RGS spectra shows FeXVII emission lines indicating the presence of gas around 0.5keV. There is no evidence for OVII emission which would imply gas at still cooler tem…
Measures of star formation rates from infrared (Herschel) and UV (GALEX) emissions of galaxies in the HerMES fields
Altieri, B.; Aussel, H.; Elbaz, D. +75 more
The reliability of infrared (IR) and ultraviolet (UV) emissions to measure star formation rates (SFRs) in galaxies is investigated for a large sample of galaxies observed with the Spectral and Photometric Imaging Receiver (SPIRE) and the Photodetector Array Camera and Spectrometer (PACS) instruments on Herschel as part of the Herschel Multi-Tiered…
HerMES: SPIRE Science Demonstration Phase maps†‡
Pérez-Fournon, I.; Franceschini, A.; Bock, J. +30 more
We describe the production and verification of sky maps of the five Spectral and Photometric Imaging Receiver (SPIRE) fields observed as part of the Herschel Multi-tiered Extragalactic Survey (HerMES) during the Science Demonstration Phase (SDP) of the Herschel mission. We have implemented an iterative map-making algorithm [The SPIRE-HerMES Iterat…
Herschel-SPIRE, far-infrared properties of millimetre-bright and -faint radio galaxies
Pérez-Fournon, I.; Rodighiero, G.; Ivison, R. J. +34 more
We present the first study of the far-infrared (FIR) properties of high-redshift, radio-selected ultraluminous infrared galaxies (ULIRGs) using deep observations obtained with the Spectral and Photometric Imaging Receiver (SPIRE) from the Herschel Multi-tiered Extragalactic Survey (HerMES). These galaxies span a large range of 850-µm fluxes …
Discovery of Compton-thick quasars in the Sloan Digital Sky Survey
Pozzi, F.; Alexander, D. M.; Vignali, C. +1 more
We present new and archival Chandra snapshot (~10ks each) observations of 15 optically identified [from the Sloan Digital Sky Survey (SDSS)] Type 2 quasars at z = 0.40-0.73. When combined with existing X-ray data, this work provides complete X-ray coverage for all 25 radio-quiet Type 2 quasars with logL[OIII] > 9.28Lsolar …
The star-formation history of the Small Magellanic Cloud star cluster NGC 419
Girardi, Léo; Rubele, Stefano; Kerber, Leandro
The rich Small Magellanic Cloud (SMC) star cluster NGC 419 has recently been found to present both a broad main-sequence turn-off and a dual red clump of giants in the sharp colour-magnitude diagrams (CMDs) derived from the High-Resolution Channel of the Advanced Camera for Surveys onboard the Hubble Space Telescope. In this work, we apply to the …
Probing evolutionary mechanisms in galaxy clusters: neutral atomic hydrogen in Abell1367
Hardcastle, M. J.; Croston, J. H.; Boselli, A. +6 more
We present Very Large Array HI imaging data for a field in the NW of the galaxy cluster Abell 1367 (z =0.02) in an attempt to probe the effect environment has on the interstellar medium of late-type spiral galaxies. Several galaxies, like CGCG 097-087, show pronounced tails and asymmetries, and seven out of 10 show significant, several kpc offsets…
The linear rms-flux relation in an ultraluminous X-ray source
Vaughan, S.; Heil, L. M.
We report the first detection of a linear correlation between rms variability amplitude and flux in the ultraluminous X-ray source (ULX) NGC 5408 X-1. The rms-flux relation has previously been observed in several galactic black hole X-ray binaries (BHBs), several active galactic nuclei (AGN) and at least one neutron star X-ray binary. This result …