Search Publications
The formation and assembly of a typical star-forming galaxy at redshift z~3
Richard, Johan; Stark, Daniel P.; Ellis, Richard S. +3 more
Recent studies of galaxies ~2-3Gyr after the Big Bang have revealed large, rotating disks, similar to those of galaxies today. The existence of well-ordered rotation in galaxies during this peak epoch of cosmic star formation indicates that gas accretion is likely to be the dominant mode by which galaxies grow, because major mergers of galaxies wo…
Magnetic support of the optical emission line filaments in NGC 1275
Fabian, A. C.; Gallagher, J. S., III; Conselice, C. J. +4 more
The giant elliptical galaxy NGC 1275, at the centre of the Perseus cluster, is surrounded by a well-known giant nebulosity of emission-line filaments, which are plausibly in excess of 108years old. The filaments are dragged out from the centre of the galaxy by radio-emitting `bubbles' rising buoyantly in the hot intracluster gas, before…
Water vapour jets inside the plume of gas leaving Enceladus
Hansen, C. J.; Hendrix, A. R.; Colwell, J. E. +7 more
A plume of water vapour escapes from fissures crossing the south polar region of the Saturnian moon Enceladus. Tidal deformation of a thin surface crust above an internal ocean could result in tensile and compressive stresses that would affect the width of the fissures; therefore, the quantity of water vapour released at different locations in Enc…
Heterogeneous chemistry in the atmosphere of Mars
Montmessin, Franck; Bertaux, Jean-Loup; Perrier, Séverine +6 more
Hydrogen radicals are produced in the martian atmosphere by the photolysis of water vapour and subsequently initiate catalytic cycles that recycle carbon dioxide from its photolysis product carbon monoxide. These processes provide a qualitative explanation for the stability of the atmosphere of Mars, which contains 95 per cent carbon dioxide. Bala…
An equatorial oscillation in Saturn's middle atmosphere
Strobel, D. F.; Flasar, F. M.; Bézard, B. +3 more
The middle atmospheres of planets are driven by a combination of radiative heating and cooling, mean meridional motions, and vertically propagating waves (which originate in the deep troposphere). It is very difficult to model these effects and, therefore, observations are essential to advancing our understanding of atmospheres. The equatorial str…
Depth of a strong jovian jet from a planetary-scale disturbance driven by storms
Hueso, R.; Sánchez-Lavega, A.; Rojas, J. F. +22 more
The atmospheres of the gas giant planets (Jupiter and Saturn) contain jets that dominate the circulation at visible levels. The power source for these jets (solar radiation, internal heat, or both) and their vertical structure below the upper cloud are major open questions in the atmospheric circulation and meteorology of giant planets. Several ob…
Discovery of the progenitor of the type Ia supernova 2007on
Nelemans, Gijs; Voss, Rasmus
Type Ia supernovae are exploding stars that are used to measure the accelerated expansion of the Universe and are responsible for most of the iron ever produced. Although there is general agreement that the exploding star is a white dwarf in a binary system, the exact configuration and trigger of the explosion is unclear, which could hamper their …
Semi-annual oscillations in Saturn's low-latitude stratospheric temperatures
Tokunaga, Alan T.; Baines, Kevin H.; Hora, Joseph L. +25 more
Observations of oscillations of temperature and wind in planetary atmospheres provide a means of generalizing models for atmospheric dynamics in a diverse set of planets in the Solar System and elsewhere. An equatorial oscillation similar to one in the Earth's atmosphere has been discovered in Jupiter. Here we report the existence of similar oscil…
An 84-µG magnetic field in a galaxy at redshift z = 0.692
Jorgenson, Regina A.; Heiles, Carl; Wolfe, Arthur M. +2 more
The magnetic field pervading our Galaxy is a crucial constituent of the interstellar medium: it mediates the dynamics of interstellar clouds, the energy density of cosmic rays, and the formation of stars. The field associated with ionized interstellar gas has been determined through observations of pulsars in our Galaxy. Radio-frequency measuremen…
Atmospheric structure and dynamics as the cause of ultraviolet markings in the clouds of Venus
Drossart, Pierre; Piccioni, Giuseppe; Markiewicz, Wojciech J. +4 more
When seen in ultraviolet light, Venus has contrast features that arise from the non-uniform distribution of unknown absorbers within the sulphuric acid clouds and seem to trace dynamical activity in the middle atmosphere. It has long been unclear whether the global pattern arises from differences in cloud top altitude (which was earlier estimated …