Search Publications
Comets as collisional fragments of a primordial planetesimal disk
Rickman, H.; Morbidelli, A.
Context. The Rosetta mission and its exquisite measurements have revived the debate on whether comets are pristine planetesimals or collisionally evolved objects.
Aims: We investigate the collisional evolution experienced by the precursors of current comet nuclei during the early stages of the solar system in the context of the so-called Nice…
Anatomy of the AGN in NGC 5548. II. The spatial, temporal, and physical nature of the outflow from HST/COS Observations
Kaastra, J. S.; Harrison, F. A.; Kriss, G. A. +30 more
Context. AGN outflows are thought to influence the evolution of their host galaxies and of super massive black holes. Our deep multiwavelength campaign on NGC 5548 has revealed a new, unusually strong X-ray obscuration, accompanied by broad UV absorption troughs observed for the first time in this object. The X-ray obscuration caused a dramatic de…
High-resolution imaging of the molecular outflows in two mergers: IRAS 17208-0014 and NGC 1614
Tacconi, L. J.; Hunt, L. K.; Colina, L. +11 more
Context. Galaxy evolution scenarios predict that the feedback of star formation and nuclear activity (AGN) can drive the transformation of gas-rich spiral mergers into (ultra) luminous infrared galaxies and, eventually, lead to the build-up of QSO/elliptical hosts.
Aims: We study the role that star formation and AGN feedback have in launching…
KMOS view of the Galactic centre. I. Young stars are centrally concentrated
Kuntschner, H.; Hilker, M.; Walcher, C. J. +7 more
Context. The Galactic centre hosts a crowded, dense nuclear star cluster with a half-light radius of 4 pc. Most of the stars in the Galactic centre are cool late-type stars, but there are also ≳100 hot early-type stars in the central parsec of the Milky Way. These stars are only 3-8 Myr old.
Aims: Our knowledge of the number and distribution …
Evolution of the ion environment of comet 67P/Churyumov-Gerasimenko. Observations between 3.6 and 2.0 AU
Kallio, E.; Fedorov, A.; Koskinen, H. +28 more
Context. The Rosetta spacecraft is escorting comet 67P/Churyumov-Gerasimenko from a heliocentric distance of >3.6 AU, where the comet activity was low, until perihelion at 1.24 AU. Initially, the solar wind permeates the thin comet atmosphere formed from sublimation.
Aims: Using the Rosetta Plasma Consortium Ion Composition Analyzer (RPC-I…
Peering through the holes: the far-UV color of star-forming galaxies at z ~ 3-4 and the escaping fraction of ionizing radiation
Schaerer, D.; Giavalisco, M.; Castellano, M. +11 more
Aims: We aim to investigate the effect of the escaping ionizing radiation on the color selection of high-redshift galaxies and identify candidate Lyman-continuum (LyC) emitters.
Methods: We used the intergalactic medium (IGM) prescription of Inoue et al. (2014, MNRAS, 442, 1805) and galaxy synthesis models of Bruzual & Charlot (2003,…
A novel scenario for the possible X-ray line feature at ~3.5 keV. Charge exchange with bare sulfur ions
Raassen, A. J. J.; Gu, L.; Kaastra, J. +4 more
Motivated by recent claims of a compelling ~3.5 keV emission line from nearby galaxies and galaxy clusters, we investigate a novel plasma model incorporating a charge exchange component obtained from theoretical scattering calculations. Fitting this kind of component with a standard thermal model yields positive residuals around 3.5 keV, produced …
The neutron star in HESS J1731-347: Central compact objects as laboratories to study the equation of state of superdense matter
Werner, K.; Klochkov, D.; Santangelo, A. +3 more
Context. Central compact objects (CCOs) in supernova remnants are isolated thermally emitting neutron stars (NSs). They are most probably characterized by a magnetic field strength that is roughly two orders of magnitude lower than that of most of the radio and accreting pulsars. The thermal emission of CCOs can be modeled to obtain constraints on…
First observations of H2O and CO2 vapor in comet 67P/Churyumov-Gerasimenko made by VIRTIS onboard Rosetta
Kührt, E.; Encrenaz, T.; Erard, S. +29 more
Context. Outgassing from cometary nuclei involves complex surface and subsurface processes that need to be understood to investigate the composition of cometary ices from coma observations.
Aims: We investigate the production of water, carbon dioxide, and carbon monoxide from the nucleus of comet 67P/Churyumov-Gerasimenko (67P). These species…
[C II] absorption and emission in the diffuse interstellar medium across the Galactic plane
Menten, K. M.; Falgarone, E.; Godard, B. +10 more
Aims: Ionized carbon is the main gas-phase reservoir of carbon in the neutral diffuse interstellar medium (ISM) and its 158 µm fine structure transition [C ii] is the most important cooling line of the diffuse ISM. We combine [C ii] absorption and emission spectroscopy to gain an improved understanding of physical conditions in the diff…