Search Publications
Scaling properties of a complete X-ray selected galaxy group sample
Lovisari, L.; Reiprich, T. H.; Schellenberger, G.
Context. Upcoming X-ray surveys like eROSITA require precise calibration between X-ray observables and mass down to the low-mass regime to set tight constraints on the fundamental cosmological parameters. Since an individual mass measurement is only possible for relatively few objects, it is crucial to have reliable and clearly understood scaling …
XMM-Newton and Chandra cross-calibration using HIFLUGCS galaxy clusters . Systematic temperature differences and cosmological impact
Lovisari, L.; David, L.; Reiprich, T. H. +2 more
Context. Robust X-ray temperature measurements of the intracluster medium (ICM) of galaxy clusters require an accurate energy-dependent effective area calibration. Since the hot gas X-ray emission of galaxy clusters does not vary on relevant timescales, they are excellent cross-calibration targets. Moreover, cosmological constraints from clusters …
Properties of flat-spectrum radio-loud narrow-line Seyfert 1 galaxies
Maraschi, L.; Tagliaferri, G.; Lähteenmäki, A. +27 more
We have conducted a multiwavelength survey of 42 radio loud narrow-1ine Seyfert 1 galaxies (RLNLS1s), selected by searching among all the known sources of this type and omitting those with steep radio spectra. We analyse data from radio frequencies to X-rays, and supplement these with information available from online catalogues and the literature…
Anatomy of the AGN in NGC 5548. I. A global model for the broadband spectral energy distribution
Kaastra, J. S.; Harrison, F. A.; Kriss, G. A. +24 more
An extensive multi-satellite campaign on NGC 5548 has revealed this archetypal Seyfert-1 galaxy to be in an exceptional state of persistent heavy absorption. Our observations taken in 2013-2014 with XMM-Newton, Swift, NuSTAR, INTEGRAL, Chandra, HST and two ground-based observatories have together enabled us to establish that this unexpected phenom…
The truncated and evolving inner accretion disc of the black hole GX 339-4
Ponti, G.; Fender, R. P.; Muñoz-Darias, T. +2 more
The nature of accretion onto stellar mass black holes in the low/hard state remains unresolved, with some evidence suggesting that the inner accretion disc is truncated and replaced by a hot flow. However, the detection of relativistic broadened Fe emission lines, even at relatively low luminosities, seems to require an accretion disc extending fu…
Occurrence of radio halos in galaxy clusters. Insight from a mass-selected sample
Brunetti, G.; Kale, R.; Venturi, T. +4 more
Context. Giant radio halos (RH) are diffuse Mpc-scale synchrotron sources detected in some massive and merging galaxy clusters. An unbiased study of the statistical properties of RHs is crucial to constraining their origin and evolution.
Aims: We investigate the occurrence of RHs and its dependence on the cluster mass in a Sunyaev-Zel'dovich …
Galaxy-wide outflows in z ~ 1.5 luminous obscured quasars revealed through near-IR slit-resolved spectroscopy
Maiolino, R.; Salvato, M.; Marconi, A. +10 more
Aims: The co-evolution of galaxies and supermassive black holes (SMBHs) requires that some sort of feedback mechanism is operating during the active galactic nuclei (AGN) phases. AGN driven winds are the most likely candidates for such feedback mechanism, but direct observational evidence of their existence and of their effects on the host ga…
The VLT/NaCo large program to probe the occurrence of exoplanets and brown dwarfs in wide orbits. I. Sample definition and characterization
Moutou, C.; Henning, T.; Alcalá, J. M. +28 more
Context. Young, close stars are ideal targets for searching planets using the direct imaging technique. The determination of stellar parameters is crucial for the interpretation of imaging survey results, particularly since the luminosity of substellar objects has a strong dependence on system age.
Aims: We have conducted a large program with…
The Extended GMRT Radio Halo Survey. II. Further results and analysis of the full sample
Brunetti, G.; Kale, R.; Giacintucci, S. +6 more
The intra-cluster medium contains cosmic rays and magnetic fields that are manifested through the large scale synchrotron sources, termed radio haloes, relics, and mini-haloes. The Extended Giant Metrewave Radio Telescope (GMRT) Radio Halo Survey (EGRHS) is an extension of the GMRT Radio Halo Survey (GRHS) designed to search for radio haloes using…
Compton thick AGN in the XMM-COSMOS survey
Berta, S.; Pozzi, F.; Georgakakis, A. +27 more
Heavily obscured, Compton thick (CT, NH> 1024 cm-2) active galactic nuclei (AGN) may represent an important phase in AGN/galaxy co-evolution and are expected to provide a significant contribution to the cosmic X-ray background at its peak. However, unambiguously identifying CT AGN beyond the local Universe is a …