Search Publications
Quasars as standard candles. I. The physical relation between disc and coronal emission
Lusso, E.; Risaliti, G.
Context. A tight non-linear relation exists between the X-ray and UV emission in quasars (I.e. LX ∝LUVγ), with a dispersion of 0.2 dex over approximately three orders of magnitude in luminosity. Such observational evidence has two relevant consequences: (1) an ubiquitous physical mechanism must regulate the energy transfer fr…
A refined mass distribution of the cluster MACS J0416.1-2403 from a new large set of spectroscopic multiply lensed sources
Grillo, C.; Tozzi, P.; Balestra, I. +11 more
We report the spectroscopic confirmation of 22 new multiply lensed sources behind the Hubble Frontier Field (HFF) galaxy cluster MACS J0416.1-2403 (MACS 0416), using archival data from the Multi Unit Spectroscopic Explorer (MUSE) on the VLT. Combining with previous spectroscopic measurements of 15 other multiply imaged sources, we have obtained a …
Structure of Herbig AeBe disks at the milliarcsecond scale . A statistical survey in the H band using PIONIER-VLTI
Pinte, C.; Ménard, F.; Absil, O. +26 more
Context. It is now generally accepted that the near-infrared excess of Herbig AeBe stars originates in the dust of a circumstellar disk.
Aims: The aims of this article are to infer the radial and vertical structure of these disks at scales of order 1 au, and the properties of the dust grains.
Methods: The program objects (51 in total) we…
The global meter-level shape model of comet 67P/Churyumov-Gerasimenko
Jorda, L.; Lara, L. M.; Bertaux, J. -L. +42 more
We performed a stereo-photogrammetric (SPG) analysis of more than 1500 Rosetta/OSIRIS NAC images of comet 67P/Churyumov-Gerasimenko (67P). The images with pixel scales in the range 0.2-3.0 m/pixel were acquired between August 2014 and February 2016. We finally derived a global high-resolution 3D description of 67P's surface, the SPG SHAP7 shape mo…
Molecular gas in the Herschel-selected strongly lensed submillimeter galaxies at z 2-4 as probed by multi-J CO lines
Smail, I.; Omont, A.; Cooray, A. +18 more
We present the IRAM-30 m observations of multiple-J CO (Jup mostly from 3 up to 8) and [C I](3P2 → 3P1) ([C I](2-1) hereafter) line emission in a sample of redshift ~2-4 submillimeter galaxies (SMGs). These SMGs are selected among the brightest-lensed galaxies discovered in the Herschel-Astrop…
The VIMOS Ultra Deep Survey first data release: Spectra and spectroscopic redshifts of 698 objects up to zspec 6 in CANDELS
Maccagni, D.; Cimatti, A.; Ilbert, O. +45 more
This paper describes the first data release (DR1) of the VIMOS Ultra Deep Survey (VUDS). The VUDS-DR1 is the release of all low-resolution spectroscopic data obtained in 276.9 arcmin2 of the CANDELS-COSMOS and CANDELS-ECDFS survey areas, including accurate spectroscopic redshifts zspec and individual spectra obtained with VIM…
Non-LTE aluminium abundances in late-type stars
Lind, K.; Nordlander, T.
Aims: Aluminium plays a key role in studies of the chemical enrichment of the Galaxy and of globular clusters. However, strong deviations from LTE (non-LTE) are known to significantly affect the inferred abundances in giant and metal-poor stars.
Methods: We present non-local thermodynamic equilibrium (NLTE) modeling of aluminium using re…
The long egress of GJ 436b's giant exosphere
Heng, K.; Thomas, N.; Ehrenreich, D. +8 more
The M dwarf GJ 436 hosts a transiting warm Neptune known to experience atmospheric escape. Previous observations revealed the presence of a giant hydrogen exosphere transiting the star for more than 5 h, and absorbing up to 56% of the flux in the blue wing of the stellar Lyman-α line of neutral hydrogen (H I Lyα). The unexpected size of this comet…
The Galactic Center Molecular Cloud Survey. I. A steep linewidth-size relation and suppression of star formation
Lu, Xing; Menten, Karl M.; Zhang, Qizhou +4 more
The central molecular zone (CMZ; inner 200 pc) of the Milky Way is a star formation (SF) environment with very extreme physical properties. Exploration of SF in this region is important because (I) this region allows us to test models of star formation under exceptional conditions; and (II) the CMZ clouds might be suitable to serve as templates to…
A box full of chocolates: The rich structure of the nearby stellar halo revealed by Gaia and RAVE
Tian, Hao; Helmi, Amina; Sales, Laura V. +2 more
Context. The hierarchical structure formation model predicts that stellar halos should form, at least partly, via mergers. If this was a predominant formation channel for the Milky Way's halo, imprints of this merger history in the form of moving groups or streams should also exist in the vicinity of the Sun.
Aims: We study the kinematics of …