Search Publications
Transport of solar wind into Earth's magnetosphere through rolled-up Kelvin-Helmholtz vortices
Balogh, A.; Hasegawa, H.; Fujimoto, M. +5 more
Establishing the mechanisms by which the solar wind enters Earth's magnetosphere is one of the biggest goals of magnetospheric physics, as it forms the basis of space weather phenomena such as magnetic storms and aurorae. It is generally believed that magnetic reconnection is the dominant process, especially during southward solar-wind magnetic fi…
Solar chromospheric spicules from the leakage of photospheric oscillations and flows
De Pontieu, Bart; Erdélyi, Robert; James, Stewart P.
Spicules are dynamic jets propelled upwards (at speeds of ~20kms-1) from the solar `surface' (photosphere) into the magnetized low atmosphere of the Sun. They carry a mass flux of 100 times that of the solar wind into the low solar corona. With diameters close to observational limits (< 500km), spicules have been largely unexplained …
Recent and episodic volcanic and glacial activity on Mars revealed by the High Resolution Stereo Camera
Jaumann, R.; Head, J. W.; Neukum, G. +9 more
The large-area coverage at a resolution of 10-20metres per pixel in colour and three dimensions with the High Resolution Stereo Camera Experiment on the European Space Agency Mars Express Mission has made it possible to study the time-stratigraphic relationships of volcanic and glacial structures in unprecedented detail and give insight into the g…
Old galaxies in the young Universe
Cimatti, A.; Daddi, E.; Rodighiero, G. +8 more
More than half of all stars in the local Universe are found in massive spheroidal galaxies, which are characterized by old stellar populations with little or no current star formation. In present models, such galaxies appear rather late in the history of the Universe as the culmination of a hierarchical merging process, in which larger galaxies ar…
The massive binary companion star to the progenitor of supernova 1993J
Smartt, Stephen J.; Kudritzki, Rolf P.; Podsiadlowski, Philipp +2 more
The massive star that underwent a collapse of its core to produce supernova (SN)1993J was subsequently identified as a non-variable red supergiant star in images of the galaxy M81 taken before explosion. It showed an excess in ultraviolet and B-band colours, suggesting either the presence of a hot, massive companion star or that it was embedded in…
Perennial water ice identified in the south polar cap of Mars
Sotin, C.; Drossart, Pierre; Forni, O. +39 more
The inventory of water and carbon dioxide reservoirs on Mars are important clues for understanding the geological, climatic and potentially exobiological evolution of the planet. From the early mapping observation of the permanent ice caps on the martian poles, the northern cap was believed to be mainly composed of water ice, whereas the southern …
The binary progenitor of Tycho Brahe's 1572 supernova
Filippenko, Alexei V.; Foley, Ryan J.; Ibata, Rodrigo +8 more
The brightness of type Ia supernovae, and their homogeneity as a class, makes them powerful tools in cosmology, yet little is known about the progenitor systems of these explosions. They are thought to arise when a white dwarf accretes matter from a companion star, is compressed and undergoes a thermonuclear explosion. Unless the companion star is…
The sub-energetic γ-ray burst GRB 031203 as a cosmic analogue to the nearby GRB 980425
Cenko, S. B.; Berger, E.; Frail, D. A. +13 more
Over the six years since the discovery of the γ-ray burst GRB 980425, which was associated with the nearby (distance ~40Mpc) supernova 1998bw, astronomers have debated fiercely the nature of this event. Relative to bursts located at cosmological distance (redshift z ~ 1), GRB 980425 was under-luminous in γ-rays by three orders of magnitude. Radio …
An apparently normal γ-ray burst with an unusually low luminosity
Sunyaev, R. A.; Sazonov, S. Yu.; Lutovinov, A. A.
Much of the progress in understanding γ-ray bursts (GRBs) has come from studies of distant events (redshift z ~ 1). In the brightest GRBs, the γ-rays are so highly collimated that the events can be seen across the Universe. It has long been suspected that the nearest and most common events have been missed because they are not as collimated or the…
A large population of `Lyman-break' galaxies in a protocluster at redshift z ~ 4.1
White, Richard L.; Franx, Marijn; Illingworth, Garth D. +35 more
The most massive galaxies and the richest clusters are believed to have emerged from regions with the largest enhancements of mass density relative to the surrounding space. Distant radio galaxies may pinpoint the locations of the ancestors of rich clusters, because they are massive systems associated with `overdensities' of galaxies that are brig…