Search Publications
Why do protoplanetary disks appear not massive enough to form the known exoplanet population?
Manara, C. F.; Morbidelli, A.; Guillot, T.
When and how planets form in protoplanetary disks is still a topic of discussion. Exoplanet detection surveys and protoplanetary disk surveys are now providing results that are leading to new insights. We collect the masses of confirmed exoplanets and compare their dependence on stellar mass with the same dependence for protoplanetary disk masses …
The evolution of the X-ray afterglow emission of GW 170817/ GRB 170817A in XMM-Newton observations
Covino, S.; D'Avanzo, P.; Campana, S. +12 more
We report our observation of the short gamma-ray burst (GRB) GRB 170817A, associated to the binary neutron star merger gravitational wave (GW) event GW 170817, performed in the X-ray band with XMM-Newton 135 d after the event (on 29 December, 2017). We find evidence for a flattening of the X-ray light curve with respect to the previously observed …
Three-dimensional maps of interstellar dust in the Local Arm: using Gaia, 2MASS, and APOGEE-DR14
Arenou, F.; Babusiaux, C.; Leclerc, N. +6 more
Context. Gaia data and stellar surveys open the way to the construction of detailed 3D maps of the Galactic interstellar (IS) dust based on the synthesis of star distances and extinctions. Dust maps are tools of broad use, also for Gaia-related Milky Way studies.
Aims: Reliable extinction measurements require very accurate photometric calibra…
Gaia Data Release 2. The celestial reference frame (Gaia-CRF2)
Prusti, T.; Mazeh, T.; Zucker, S. +449 more
Context. The second release of Gaia data (Gaia DR2) contains the astrometric parameters for more than half a million quasars. This set defines a kinematically non-rotating reference frame in the optical domain. A subset of these quasars have accurate VLBI positions that allow the axes of the reference frame to be aligned with the International Cel…
A new method for unveiling open clusters in Gaia. New nearby open clusters confirmed by DR2
Castro-Ginard, A.; Jordi, C.; Luri, X. +4 more
Context. The publication of the Gaia Data Release 2 (Gaia DR2) opens a new era in astronomy. It includes precise astrometric data (positions, proper motions, and parallaxes) for more than 1.3 billion sources, mostly stars. To analyse such a vast amount of new data, the use of data-mining techniques and machine-learning algorithms is mandatory.
Starbursts in and out of the star-formation main sequence
Daddi, E.; Elbaz, D.; Franco, M. +13 more
Aims: We use high-resolution continuum images obtained with the Atacama Large Millimeter Array (ALMA) to probe the surface density of star formation in z ~ 2 galaxies and study the different physical properties between galaxies within and above the star-formation main sequence of galaxies.
Methods: We use ALMA images at 870 µm with…
Hubble PanCET: an extended upper atmosphere of neutral hydrogen around the warm Neptune GJ 3470b
Sanz-Forcada, J.; Ehrenreich, D.; Lecavelier des Etangs, A. +16 more
GJ 3470b is a warm Neptune transiting an M-dwarf star at the edge of the evaporation desert. It offers the possibility of investigating how low-mass, close-in exoplanets evolve under the irradiation from their host stars. We observed three transits of GJ 3470b in the Lyman-α line with the Hubble Space Telescope (HST) as part of the Panchromatic Co…
Testing warm Comptonization models for the origin of the soft X-ray excess in AGNs
Bianchi, S.; Cappi, M.; Petrucci, P. -O. +5 more
The X-ray spectra of many active galactic nuclei (AGNs) show a soft X-ray excess below 1-2 keV on top of the extrapolated high-energy power law. The origin of this component is uncertain. It could be a signature of relativistically blurred, ionized reflection or the high-energy tail of thermal Comptonization in a warm (kT 1 keV), optically thick (…
Direct mapping of the temperature and velocity gradients in discs. Imaging the vertical CO snow line around IM Lupi
Pinte, C.; Ménard, F.; Duchêne, G. +14 more
Accurate measurements of the physical structure of protoplanetary discs are critical inputs for planet formation models. These constraints are traditionally established via complex modelling of continuum and line observations. Instead, we present an empirical framework to locate the CO isotopologue emitting surfaces from high spectral and spatial …
Open cluster kinematics with Gaia DR2
Castro-Ginard, A.; Jordi, C.; Casamiquela, L. +16 more
Context. Open clusters are very good tracers of the evolution of the Galactic disc. Thanks to Gaia, their kinematics can be investigated with an unprecedented precision and accuracy.
Aims: The distribution of open clusters in the 6D phase space is revisited with Gaia DR2.
Methods: The weighted mean radial velocity of open clusters was de…