Search Publications
The XMM-Newton survey of the ELAIS-S1 field. I. Number counts, angular correlation function and X-ray spectral properties
Berta, S.; D'Elia, V.; Fiore, F. +16 more
Aims.The formation and evolution of cosmic structures can be probed by studying the evolution of the luminosity function of the Active Galactic Nuclei (AGNs), galaxies and clusters of galaxies and of the clustering of the X-ray active Universe, compared to the IR-UV active Universe.
Methods: .To this purpose, we have surveyed with XMM-Newton t…
The supermassive black hole in Centaurus A: a benchmark for gas kinematical measurements
Marconi, A.; Capetti, A.; Koekemoer, A. M. +5 more
We present new HST Space Telescope Imaging Spectrograph observations of the nearby radio galaxy NGC 5128 (Centaurus A). The bright emission line with longest wavelength accessible from HST, [S III]λ 9533 Å, was used to study the kinematics of the ionized gas in the nuclear region with a 0.1 arcsec spatial resolution. The STIS data were analized in…
Multifrequency variability of the blazar AO 0235+164 . The WEBT campaign in 2004-2005 and long-term SED analysis
Lee, C. -U.; Ilyin, I.; Lähteenmäki, A. +58 more
Aims.A huge multiwavelength campaign targeting the blazar
Methods: .Monitoring observations were carried out at cm and mm wavelengths, and in the near-IR and optical bands, while three pointing…
Planetary nebulae abundances and stellar evolution
Pottasch, S. R.; Bernard-Salas, J.
A summary is given of planetary nebulae abundances from ISO measurements. It is shown that these nebulae show abundance gradients (with galactocentric distance), which in the case of neon, argon, sulfur and oxygen (with four exceptions) are the same as HII regions and early type star abundance gradients. The abundance of these elements predicted f…
Non-thermal cosmic backgrounds from blazars: the contribution to the CMB, X-ray and γ-ray backgrounds
Cavazzuti, E.; Colafrancesco, S.; Giommi, P. +2 more
We present a new assessment of the contribution of the blazar population to the extragalactic background radiation across the electromagnetic spectrum. Our calculations rely on deep blazar radio counts that we have derived by combining several radio and multi-frequency surveys. We show that blazar emission integrated over cosmic time gives rise to…
Bimodal spectral variability of Cygnus X-1 in an intermediate state
Belloni, T.; Chaty, S.; Rodriguez, J. +11 more
We report the results of an observation of
Solar coronal-hole plasma densities and temperatures
Wilhelm, K.
Polar plumes extending from the Sun into the solar corona have long been seen during eclipses, and can now be studied without this restriction with telescopes and spectrometers on board of spacecraft. Despite the large amount of observational data available on this prominent phenomenon, it is not clear whether plumes contribute substantially to th…
Mid infrared properties of distant infrared luminous galaxies
Elbaz, D.; Morrison, G.; Dickinson, M. +3 more
We present evidence that the mid infrared (MIR, rest frame 5-30 µm) is a good tracer of the total infrared luminosity, L(IR)(=L[8{-}1000 µm]), and star formation rate (SFR), of galaxies up to z∼ 1.3. We use deep MIR images from the Infrared Space Observatory (ISO) and the Spitzer Space Telescope in the Northern field of the Great Obser…
The radio to TeV orbital variability of the microquasar LS I +61 303
Paredes, J. M.; Romero, G. E.; Ribó, M. +1 more
Context: .The microquasar LS I +61 303 has recently been detected at TeV energies by the Cherenkov telescope MAGIC, presenting variability on timescales similar to its orbital period. This system has been intensively observed at different wavelengths during the last three decades, showing a very complex behavior along the orbit.
Aims: .We aim …
Comparing dynamical and photometric-stellar masses of early-type galaxies at z ~ 1
Cimatti, A.; Popesso, P.; Stern, D. +13 more
Aims.The purpose of this study is to explore the relationship between galaxy stellar masses, based on multiwavelength photometry spectral template fitting and dynamical masses based on published velocity dispersion measurements, for a sample of 48 early-type galaxies at z ∼ 1 with HST/ACS morphological information.
Methods: .We determine photo…