Search Publications
First high-energy observations of narrow-line Seyfert 1s with INTEGRAL/IBIS
de Rosa, A.; Masetti, N.; Bird, A. J. +8 more
Narrow-line Seyfert 1 (NLS1) galaxies are very interesting objects which display peculiar properties when compared to their broad-line analogues (BLS1). Although well studied in many wavebands, their behaviour at >10 keV is poorly studied and yet important to discriminate between models invoked to explain the complexity observed in the X-ray ba…
Two-dimensional kinematics of SLACS lenses - I. Phase-space analysis of the early-type galaxy SDSSJ2321-097 at z ~ 0.1
Treu, Tommaso; Czoske, Oliver; Koopmans, Léon V. E. +2 more
We present the first results of a combined VLT VIMOS integral-field unit and Hubble Space Telescope (HST)/ACS study of the early-type lens galaxy SDSSJ2321-097 at z = 0.0819, extending kinematic studies to a look-back time of 1Gyr. This system, discovered in the Sloan Lens ACS Survey, has been observed as part of a VLT Large Programme with the goa…
NGC 3147: a `true' type 2 Seyfert galaxy without the broad-line region
Bianchi, S.; Jiménez-Bailón, E.; Barcons, X. +5 more
We report on simultaneous optical and X-ray observations of the Seyfert galaxy, NGC 3147. The XMM-Newton spectrum shows that the source is unabsorbed in the X-rays (NH < 5 × 1020 cm-2). On the other hand, no broad lines are present in the optical spectrum. The origin of this optical/X-rays misclassification (wit…
SDSSJ124155.33+114003.7 - a missing link between compact elliptical and ultracompact dwarf galaxies
Mamon, Gary A.; Chilingarian, Igor V.
We report the discovery of a compact object (Re = 32 pc, MB = -12.34 mag) at a projected distance of 9 kpc from Messier 59, a giant elliptical in the Virgo cluster. Using HST imaging and SDSS spectroscopy, both available in the Virtual Observatory, we find that this object has a blue core containing one-quarter of the light, …
Integral field spectroscopy of planetary nebulae: mapping the line diagnostics and hydrogen-poor zones with VLT FLAMES
Tsamis, Y. G.; Walsh, J. R.; Barlow, M. J. +3 more
Results from the first dedicated study of Galactic planetary nebulae (PNe) by means of optical integral field spectroscopy with the Very Large Telescope Fibre Large Array Multi Element Spectrograph Argus integral field unit are presented. Three typical Galactic disc PNe have been mapped with the 11.5 × 7.2-arcsec2 Argus array: 2D spectr…
Diffuse UV light associated with the Spiderweb Galaxy: evidence for in situ star formation outside galaxies
Röttgering, H. J. A.; Miley, G. K.; Overzier, R. A. +2 more
We present detailed images of diffuse ultraviolet (UV) intergalactic light (IGL), situated in a 60-kpc halo that surrounds the radio galaxy MRC1138-262 at z = 2. We discuss the nature of the IGL and rule out faint cluster galaxies, nebular continuum emission, synchrotron, inverse Compton, synchrotron self-Compton emission and scattering of galacti…
Gravitational lenses and lens candidates identified from the COSMOS field
Jackson, Neal
A complete manual search has been carried out of the list of 285423 objects, nearly all of them galaxies, identified in the Cosmic Evolution Survey (COSMOS) field that are brighter than I = 25. Two certain and one highly probable new gravitational lenses are found, in addition to the lenses and candidate lens systems previously found by Faure et a…
Spectral variability of GX339-4 in a hard-to-soft state transition
Belloni, T.; Ubertini, P.; Malzac, J. +2 more
We report on INTEGRAL observations of the bright black hole transient GX339-4 performed during the period 2004 August-September, including the fast transition (10h) observed simultaneously with INTEGRAL and RXTE on August 15 and previously reported. Our data cover three different spectral states, namely hard/intermediate state (HIMS), soft/interme…
X-ray spectra from magnetar candidates - II. Resonant cross-sections for electron-photon scattering in the relativistic regime
Zane, S.; Nobili, L.; Turolla, R.
Recent models of spectral formation in magnetars called renewed attention on electron-photon scattering in the presence of ultrastrong magnetic fields. Investigations presented so far mainly focused on mildly relativistic particles and magnetic scattering was treated in the non-relativistic (Thomson) limit. This allows for consistent spectral calc…
The 2008 May burst activation of SGR1627-41
Sakamoto, T.; Tiengo, A.; de Luca, A. +16 more
In 2008 May, the soft gamma-ray repeater (SGR) SGR1627-41 resumed its bursting activity after nearly a decade of quiescence. After detection of a bright burst, Swift pointed its X-ray telescope in the direction of the source in less than five hours and followed it for over five weeks. In this Letter, we present an analysis of the data from these S…