Search Publications
Galaxies at redshifts 5 to 6 with systematically low dust content and high [C II] emission
Ilbert, O.; Yan, L.; Carollo, C. M. +11 more
The rest-frame ultraviolet properties of galaxies during the first three billion years of cosmic time (redshift z > 4) indicate a rapid evolution in the dust obscuration of such galaxies. This evolution implies a change in the average properties of the interstellar medium, but the measurements are systematically uncertain owing to untested assu…
A giant comet-like cloud of hydrogen escaping the warm Neptune-mass exoplanet GJ 436b
Sing, David K.; Wheatley, Peter J.; Désert, Jean-Michel +8 more
Exoplanets orbiting close to their parent stars may lose some fraction of their atmospheres because of the extreme irradiation. Atmospheric mass loss primarily affects low-mass exoplanets, leading to the suggestion that hot rocky planets might have begun as Neptune-like, but subsequently lost all of their atmospheres; however, no confident measure…
Ongoing hydrothermal activities within Enceladus
Postberg, Frank; Altobelli, Nicolas; Sekine, Yasuhito +12 more
Detection of sodium-salt-rich ice grains emitted from the plume of the Saturnian moon Enceladus suggests that the grains formed as frozen droplets from a liquid water reservoir that is, or has been, in contact with rock. Gravitational field measurements suggest a regional south polar subsurface ocean of about 10 kilometres thickness located beneat…
Wind from the black-hole accretion disk driving a molecular outflow in an active galaxy
Veilleux, S.; Reynolds, C. S.; Tombesi, F. +3 more
Powerful winds driven by active galactic nuclei are often thought to affect the evolution of both supermassive black holes and their host galaxies, quenching star formation and explaining the close relationship between black holes and galaxies. Recent observations of large-scale molecular outflows in ultraluminous infrared galaxies support this qu…
A dusty, normal galaxy in the epoch of reionization
Richard, Johan; Gallazzi, Anna; Christensen, Lise +3 more
Candidates for the modest galaxies that formed most of the stars in the early Universe, at redshifts z > 7, have been found in large numbers with extremely deep restframe-ultraviolet imaging. But it has proved difficult for existing spectrographs to characterize them using their ultraviolet light. The detailed properties of these galaxies could…
Small-scale filament eruptions as the driver of X-ray jets in solar coronal holes
Moore, Ronald L.; Sterling, Alphonse C.; Falconer, David A. +1 more
Solar X-ray jets are thought to be made by a burst of reconnection of closed magnetic field at the base of a jet with ambient open field. In the accepted version of the `emerging-flux' model, such a reconnection occurs at a plasma current sheet between the open field and the emerging closed field, and also forms a localized X-ray brightening that …
Abundant molecular oxygen in the coma of comet 67P/Churyumov-Gerasimenko
Wurz, P.; Bochsler, P.; Altwegg, K. +30 more
The composition of the neutral gas comas of most comets is dominated by H2O, CO and CO2, typically comprising as much as 95 per cent of the total gas density. In addition, cometary comas have been found to contain a rich array of other molecules, including sulfuric compounds and complex hydrocarbons. Molecular oxygen (O2…
Flows of X-ray gas reveal the disruption of a star by a massive black hole
Ramirez-Ruiz, Enrico; Cenko, S. Bradley; Drake, Jeremy J. +18 more
Tidal forces close to massive black holes can violently disrupt stars that make a close approach. These extreme events are discovered via bright X-ray and optical/ultraviolet flares in galactic centres. Prior studies based on modelling decaying flux trends have been able to estimate broad properties, such as the mass accretion rate. Here we report…
Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse
Bertaux, Jean-Loup; Naletto, Giampiero; Debei, Stefano +64 more
Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision …
The diurnal cycle of water ice on comet 67P/Churyumov-Gerasimenko
Langevin, Y.; Bellucci, G.; Jaumann, R. +77 more
Observations of cometary nuclei have revealed a very limited amount of surface water ice, which is insufficient to explain the observed water outgassing. This was clearly demonstrated on comet 9P/Tempel 1, where the dust jets (driven by volatiles) were only partially correlated with the exposed ice regions. The observations of 67P/Churyumov-Gerasi…