A very luminous magnetar-powered supernova associated with an ultra-long γ-ray burst
Nature 523, 7559 (2015). doi:10.1038/nature14579
Authors: Jochen Greiner, Paolo A. Mazzali, D. Alexander Kann, Thomas Krühler, Elena Pian, Simon Prentice, Felipe Olivares E., Andrea Rossi, Sylvio Klose, Stefan Taubenberger, Fabian Knust, Paulo M. J. Afonso, Chris Ashall, Jan Bolmer, Corentin Delvaux, Roland Diehl, Jonathan Elliott, Robert Filgas, Johan P. U. Fynbo, John F. Graham, Ana Nicuesa Guelbenzu, Shiho Kobayashi, Giorgos Leloudas, Sandra Savaglio, Patricia Schady, Sebastian Schmidl, Tassilo Schweyer, Vladimir Sudilovsky, Mohit Tanga, Adria C. Updike, Hendrik van Eerten & Karla Varela
A new class of ultra-long-duration (more than 10,000 seconds) γ-ray bursts has recently been suggested. They may originate in the explosion of stars with much larger radii than those producing normal long-duration γ-ray bursts or in the tidal disruption of a star. No clear supernova has yet been associated with an ultra-long-duration γ-ray burst. Here we report that a supernova (SN 2011kl) was associated with the ultra-long-duration γ-ray burst GRB 111209A, at a redshift z of 0.677. This supernova is more than three times more luminous than type Ic supernovae associated with long-duration γ-ray bursts, and its spectrum is distinctly different. The slope of the continuum resembles those of super-luminous supernovae, but extends further down into the rest-frame ultraviolet implying a low metal content. The light curve evolves much more rapidly than those of super-luminous supernovae. This combination of high luminosity and low metal-line opacity cannot be reconciled with typical type Ic supernovae, but can be reproduced by a model where extra energy is injected by a strongly magnetized neutron star (a magnetar), which has also been proposed as the explanation for super-luminous supernovae.
Feedback in low-mass galaxies in the early Universe
Nature 523, 7559 (2015). doi:10.1038/nature14454
Authors: Dawn K. Erb
The formation, evolution and death of massive stars release large quantities of energy and momentum into the gas surrounding the sites of star formation. This process, generically termed ‘feedback’, inhibits further star formation either by removing gas from the galaxy, or by heating it to temperatures that are too high to form new stars. Observations reveal feedback in the form of galactic-scale outflows of gas in galaxies with high rates of star formation, especially in the early Universe. Feedback in faint, low-mass galaxies probably facilitated the escape of ionizing radiation from galaxies when the Universe was about 500 million years old, so that the hydrogen between galaxies changed from neutral to ionized—the last major phase transition in the Universe.
Astrophysics: A twist in the tale of γ-ray bursts
Nature 523, 7559 (2015). doi:10.1038/523164b
Authors: Stephen J. Smartt
An unusually long burst of γ-rays zapped Earth in December 2011, lasting 4 hours. The cause of this burst is now proposed to be a peculiar supernova produced by a spinning magnetic neutron star. See Letter p.189
Pluto fly-by: a graphical guide to the historic mission
Nature 523, 7559 (2015). http://www.nature.com/doifinder/10.1038/523140a
Author: Alexandra Witze
New Horizons mission is set to speed past an ice world at the fringes of the Solar System.