Search Publications
Multi-line Herschel/HIFI observations of water reveal infall motions and chemical segregation around high-mass protostars
Shipman, R. F.; Braine, J.; van der Tak, F. F. S. +3 more
Context. The physical conditions during high-mass star formation are poorly understood. Outflow and infall motions have been detected around massive protostellar objects, but their dependence on mass, luminosity, and age is unclear. In addition, physical conditions and molecular abundances are often estimated using simple assumptions such as spher…
A NuSTAR view of powerful γ-ray loud blazars
Tagliaferri, G.; Ghirlanda, G.; Ghisellini, G. +6 more
We observed three blazars at z > 2 with the NuSTAR satellite. These were detected in the γ-rays by Fermi/LAT and in the soft X-rays, but have not yet been observed above 10 keV. The flux and slope of their X-ray continuum, together with Fermi/LAT data allows us to estimate their total electromagnetic output and peak frequency. For some of them …
Broadband spectral analysis of MXB 1659-298 in its soft and hard state
Sanna, A.; Di Salvo, T.; Burderi, L. +7 more
Context. The X-ray transient eclipsing source MXB 1659-298 went into outburst in 1999 and 2015. During these two outbursts the source was observed by XMM-Newton, NuSTAR, and Swift/XRT.
Aims: Using these observations, we studied the broadband spectrum of the source to constrain the continuum components and to verify whether it had a reflection…
Effect of the non-uniform solar chromospheric Lyα radiation on determining the coronal H I outflow velocity
Sasso, C.; Romoli, M.; Andretta, V. +13 more
We derived maps of the solar wind outflow velocity of coronal neutral hydrogen atoms at solar minimum in the altitude range 1.5-4.0 R⊙. We applied the Doppler dimming technique to coronagraphic observations in the UV H I Lyα line at 121.6 nm. The technique exploits the intensity reduction in the coronal line with increasing velocities o…
A deep X-ray view of the bare AGN Ark 120. VI. Geometry of the hot corona from spectroscopic and polarization signatures
Bianchi, S.; Porquet, D.; Matt, G. +9 more
Context. The spectral shape of the hard X-ray continuum of Active Galactic Nuclei (AGN) can be ascribed to inverse Compton scattering of optical/UV seed photons from the accretion disc by a hot corona of electrons. This physical process produces a polarization signal which is strongly sensitive to the geometry of the scattering medium (i.e. the ho…
Disentangling the Arcturus stream
Kushniruk, Iryna; Bensby, Thomas
Context. The Arcturus stream is an over-density of stars in velocity space and its origin has been much debated recently without any clear conclusion. The (classical) dissolved open cluster origin is essentially refuted; instead the discussions try to distinguish between an accretion, a resonant, or an external-perturbation origin for the stream. …
The GAPS Programme with HARPS-N at TNG. XVIII. Two new giant planets around the metal-poor stars HD 220197 and HD 233832
Scandariato, G.; Pagano, I.; Poretti, E. +40 more
Context. Statistical studies of exoplanets have shown that giant planets are more commonly hosted by metal-rich dwarf stars than low-metallicity stars, while no such correlation is evident for lower mass planets. The search for giant planets around metal-poor stars and the estimate of their occurrence fp is an important element in provi…
Multi-scale analysis of the Monoceros OB 1 star-forming region. I. The dense core population
Sanhueza, Patricio; Soam, Archana; Doi, Yasuo +24 more
Context. Current theories and models attempt to explain star formation globally, from core scales to giant molecular cloud scales. A multi-scale observational characterisation of an entire molecular complex is necessary to constrain them. We investigate star formation in G202.3+2.5, a ∼10 × 3 pc sub-region of the Monoceros OB1 cloud with a complex…
Comparing extrapolations of the coronal magnetic field structure at 2.5 R⊙ with multi-viewpoint coronagraphic observations
Sasso, C.; Romoli, M.; Andretta, V. +19 more
The magnetic field shapes the structure of the solar corona, but we still know little about the interrelationships between the coronal magnetic field configurations and the resulting quasi-stationary structures observed in coronagraphic images (such as streamers, plumes, and coronal holes). One way to obtain information on the large-scale structur…
Diurnal variation of dust and gas production in comet 67P/Churyumov-Gerasimenko at the inbound equinox as seen by OSIRIS and VIRTIS-M on board Rosetta
Lamy, P. L.; Lara, L. M.; Bertaux, J. -L. +53 more
Context. On 27 April 2015, when comet 67P/Churyumov-Gerasimenko was at 1.76 au from the Sun and moving toward perihelion, the OSIRIS and VIRTIS-M instruments on board the Rosetta spacecraft simultaneously observed the evolving dust and gas coma during a complete rotation of the comet.
Aims: We aim to characterize the spatial distribution of d…