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Birth of a relativistic outflow in the unusual γ-ray transient Swift J164449.3+573451
Berger, E.; Frail, D. A.; Kulkarni, S. R. +24 more
Active galactic nuclei, which are powered by long-term accretion onto central supermassive black holes, produce relativistic jets with lifetimes of at least one million years, and the observation of the birth of such a jet is therefore unlikely. Transient accretion onto a supermassive black hole, for example through the tidal disruption of a stray…
A salt-water reservoir as the source of a compositionally stratified plume on Enceladus
Kempf, S.; Postberg, F.; Srama, R. +2 more
The discovery of a plume of water vapour and ice particles emerging from warm fractures (`tiger stripes') in Saturn's small, icy moon Enceladus raised the question of whether the plume emerges from a subsurface liquid source or from the decomposition of ice. Previous compositional analyses of particles injected by the plume into Saturn's diffuse E…
Ocean-like water in the Jupiter-family comet 103P/Hartley 2
Hartogh, Paul; Bergin, Edwin A.; Blake, Geoffrey A. +10 more
For decades, the source of Earth's volatiles, especially water with a deuterium-to-hydrogen ratio (D/H) of (1.558+/-0.001)×10-4, has been a subject of debate. The similarity of Earth's bulk composition to that of meteorites known as enstatite chondrites suggests a dry proto-Earth with subsequent delivery of volatiles by local accretion …
Exclusion of a luminous red giant as a companion star to the progenitor of supernova SN 2011fe
Kulkarni, S. R.; Filippenko, Alexei V.; Cenko, S. Bradley +26 more
Type Ia supernovae are thought to result from a thermonuclear explosion of an accreting white dwarf in a binary system, but little is known of the precise nature of the companion star and the physical properties of the progenitor system. There are two classes of models: double-degenerate (involving two white dwarfs in a close binary system) and si…
A candidate redshift z~10 galaxy and rapid changes in that population at an age of 500Myr
Trenti, M.; Oesch, P. A.; Carollo, C. M. +9 more
Searches for very-high-redshift galaxies over the past decade have yielded a large sample of more than 6,000 galaxies existing just 900-2,000million years (Myr) after the Big Bang (redshifts 6>z>3 ref. 1). The Hubble Ultra Deep Field (HUDF09) data have yielded the first reliable detections of z~8 galaxies that, together with reports of a γ-r…
An actively accreting massive black hole in the dwarf starburst galaxy Henize2-10
Johnson, Kelsey E.; Reines, Amy E.; Sivakoff, Gregory R. +1 more
Supermassive black holes are now thought to lie at the heart of every giant galaxy with a spheroidal component, including our own Milky Way. The birth and growth of the first `seed' black holes in the earlier Universe, however, is observationally unconstrained and we are only beginning to piece together a scenario for their subsequent evolution. H…
Magneto-thermal convection in solar prominences
Shibata, Kazunari; Testa, Paola; Boerner, Paul +6 more
Coronal cavities are large low-density regions formed by hemispheric-scale magnetic flux ropes suspended in the Sun's outer atmosphere. They evolve over time, eventually erupting as the dark cores of coronal mass ejections. Although coronal mass ejections are common and can significantly affect planetary magnetospheres, the mechanisms by which cav…
The unusual γ-ray burst GRB 101225A from a helium star/neutron star merger at redshift 0.33
Im, M.; Fryer, C. L.; Choi, C. +31 more
Long γ-ray bursts (GRBs) are the most dramatic examples of massive stellar deaths, often associated with supernovae. They release ultra-relativistic jets, which produce non-thermal emission through synchrotron radiation as they interact with the surrounding medium. Here we report observations of the unusual GRB 101225A. Its γ-ray emission was exce…
Supermassive black holes do not correlate with dark matter haloes of galaxies
Kormendy, John; Bender, Ralf
Supermassive black holes have been detected in all galaxies that contain bulge components when the galaxies observed were close enough that the searches were feasible. Together with the observation that bigger black holes live in bigger bulges, this has led to the belief that black-hole growth and bulge formation regulate each other. That is, blac…
Submillimetre galaxies reside in dark matter haloes with masses greater than 3×1011 solar masses
Altieri, B.; Aussel, H.; Elbaz, D. +71 more
The extragalactic background light at far-infrared wavelengths comes from optically faint, dusty, star-forming galaxies in the Universe with star formation rates of a few hundred solar masses per year. These faint, submillimetre galaxies are challenging to study individually because of the relatively poor spatial resolution of far-infrared telesco…