Search Publications
An absorption origin for the X-ray spectral variability of MCG-6-30-15
Turner, T. J.; Reeves, J. N.; Miller, L.
Context: The Seyfert I galaxy MCG-6-30-15 shows one of the best examples of a broad “red wing” of emission in its X-ray spectrum at energies 2 < E < 6.4 keV, commonly interpreted as being caused by relativistically-blurred reflection close to the event horizon of the black hole.
Aims: We aim to test an alternative model in which absorpti…
Speckle interferometry with adaptive optics corrected solar data
Reardon, K.; von der Lühe, O.; Wöger, F.
Context: Adaptive optics systems are used on several advanced solar telescopes to enhance the spatial resolution of the recorded data. In all cases, the correction remains only partial, requiring post-facto image reconstruction techniques such as speckle interferometry to achieve consistent, near-diffraction limited resolution.
Aims: This stud…
LoCuSS: comparison of observed X-ray and lensing galaxy cluster scaling relations with simulations
Zhang, Y. -Y.; Finoguenov, A.; Böhringer, H. +5 more
The Local Cluster Substructure Survey (LoCuSS, Smith et al.) is a systematic multi-wavelength survey of more than 100 X-ray luminous galaxy clusters in the redshift range 0.14-0.3 selected from the ROSAT All Sky Survey. We used data on 37 LoCuSS clusters from the XMM-Newton archive to investigate the global scaling relations of galaxy clusters. Th…
Probing dust grain evolution in IM Lupi's circumstellar disc. Multi-wavelength observations and modelling of the dust disc
Pinte, C.; Ménard, F.; Duchêne, G. +19 more
Aims: We present a panchromatic study, involving a multiple technique approach, of the circumstellar disc surrounding the T Tauri star IM Lupi (Sz 82).
Methods: We have undertaken a comprehensive observational study of IM Lupi using photometry, spectroscopy, millimetre interferometry and multi-wavelength imaging. For the first time, the disc i…
PPM-Extended (PPMX) - a catalogue of positions and proper motions
Schwan, H.; Scholz, R. -D.; Piskunov, A. E. +3 more
Aims: We build a catalogue PPM-Extended (PPMX) on the ICRS system which is complete down to a well-defined limiting magnitude and contains the best presently available proper motions suited for kinematic studies in the Galaxy.
Methods: We perform a rigorous weighted least-squares adjustment of individual observations, spread over more than a c…
Evolution of tidal disruption candidates discovered by XMM-Newton
Read, A. M.; Esquej, P.; Freyberg, M. J. +8 more
Context: It has been demonstrated that active galactic nuclei are powered by gas accretion onto supermassive black holes located at their centres. The paradigm that the nuclei of inactive galaxies are also occupied by black holes was predicted long ago by theory. In the past decade, this conjecture was confirmed by the discovery of giant-amplitude…
Flows in active region loops observed by Hinode EIS
Del Zanna, G.
We aim to investigate the overall characteristics of coronal active region loops and their evolution. The Hinode database was searched for observations of active regions as they crossed the Sun centre. NOAA 10926 was selected. The morphology of this young active region did not significantly change over the course of a few days. Persistent redshift…
Detection of hot gas in the filament connecting the clusters of galaxies Abell 222 and Abell 223
Finoguenov, A.; Böhringer, H.; Simionescu, A. +4 more
Context: About half of the baryons in the local Universe are invisible and - according to simulations - their dominant fraction resides in filaments connecting clusters of galaxies in the form of low density gas with temperatures in the range of 105 < T < 107 K. This warm-hot intergalactic medium has never been detected…
The nature of UCDs: Internal dynamics from an expanded sample and homogeneous database
Ferrarese, L.; Infante, L.; Rejkuba, M. +9 more
Context: The internal dynamics of ultra-compact dwarf galaxies (UCDs) has attracted increasing attention, with most of the UCDs studied to date located in the Virgo cluster.
Aims: Our aim is to perform a comprehensive census of the internal dynamics of UCDs in the Fornax cluster, and to shed light on the nature of the interface between star cl…
Hipparcos distance estimates of the Ophiuchus and the Lupus cloud complexes
Alves, J.; Lombardi, M.; Lada, C. J.
We combine extinction maps from the Two Micron All Sky Survey (2MASS) with Hipparcos and Tycho parallaxes to obtain reliable and high-precision estimates of the distance to the Ophiuchus and Lupus dark complexes. Our analysis, based on a rigorous maximum-likelihood approach, shows that the ρ-Ophiuchi cloud is located at (119 ± 6) pc and the Lupus …