Microwave oven blamed for radio-telescope signals
Nature 521, 7551 (2015). doi:10.1038/521129f
Author: Chris Woolston
Studies about mysterious signals and super-strong spider silk triggered online chatter.
Astrophysics: Farthest galaxy measured
Nature 521, 7551 (2015). doi:10.1038/521129b
Astronomers have observed a distant galaxy as it looked just 650 million years after the Big Bang, making it the farthest galaxy to have its distance reliably measured.Pascal Oesch at Yale University in New Haven, Connecticut, and his colleagues used a telescope at the
The Andromeda galaxy is our Milky Way's nearest neighbor in space. The majestic spiral of over 100 billion stars is comparable in size to our home galaxy. At a distance of 2.5 million light-years, it is so close to us the galaxy can be seen as a cigar-shaped smudge of light high in the autumn sky. But if you could see the huge bubble of hot, diffuse plasma surrounding it, it would appear 100 times the angular diameter of the full Moon! The gargantuan halo is estimated to contain half the mass of the stars in the Andromeda galaxy itself. It can be thought of as the "atmosphere" of a galaxy. Astronomers using Hubble identified the gas in Andromeda's halo by measuring how it filtered the light of distant bright background objects called quasars. It is akin to seeing the glow of a flashlight shining through a fog. This finding promises to tell astronomers more about the evolution and structure of one of the most common types of galaxies in the universe.
Curtain eruptions from Enceladus’ south-polar terrain
Nature 521, 7550 (2015). doi:10.1038/nature14368
Authors: Joseph N. Spitale, Terry A. Hurford, Alyssa R. Rhoden, Emily E. Berkson & Symeon S. Platts
Observations of the south pole of the Saturnian moon Enceladus revealed large rifts in the south-polar terrain, informally called ‘tiger stripes’, named Alexandria, Baghdad, Cairo and Damascus Sulci. These fractures have been shown to be the sources of the observed jets of water vapour and icy particles and to exhibit higher temperatures than the surrounding terrain. Subsequent observations have focused on obtaining close-up imaging of this region to better characterize these emissions. Recent work examined those newer data sets and used triangulation of discrete jets to produce maps of jetting activity at various times. Here we show that much of the eruptive activity can be explained by broad, curtain-like eruptions. Optical illusions in the curtain eruptions resulting from a combination of viewing direction and local fracture geometry produce image features that were probably misinterpreted previously as discrete jets. We present maps of the total emission along the fractures, rather than just the jet-like component, for five times during an approximately one-year period in 2009 and 2010. An accurate picture of the style, timing and spatial distribution of the south-polar eruptions is crucial to evaluating theories for the mechanism controlling the eruptions.
An extremely young massive clump forming by gravitational collapse in a primordial galaxy
Nature 521, 7550 (2015). doi:10.1038/nature14409
Authors: A. Zanella, E. Daddi, E. Le Floc’h, F. Bournaud, R. Gobat, F. Valentino, V. Strazzullo, A. Cibinel, M. Onodera, V. Perret, F. Renaud & C. Vignali
When cosmic star formation history reaches a peak (at about redshift z ≈ 2), galaxies vigorously fed by cosmic reservoirs are dominated by gas and contain massive star-forming clumps, which are thought to form by violent gravitational instabilities in highly turbulent gas-rich disks. However, a clump formation event has not yet been observed, and it is debated whether clumps can survive energetic feedback from young stars, and afterwards migrate inwards to form galaxy bulges. Here we report the spatially resolved spectroscopy of a bright off-nuclear emission line region in a galaxy at z = 1.987. Although this region dominates star formation in the galaxy disk, its stellar continuum remains undetected in deep imaging, revealing an extremely young (less than ten million years old) massive clump, forming through the gravitational collapse of more than one billion solar masses of gas. Gas consumption in this young clump is more than tenfold faster than in the host galaxy, displaying high star-formation efficiency during this phase, in agreement with our hydrodynamic simulations. The frequency of older clumps with similar masses, coupled with our initial estimate of their formation rate (about 2.5 per billion years), supports long lifetimes (about 500 million years), favouring models in which clumps survive feedback and grow the bulges of present-day galaxies.
Mysterious galactic signal points LHC to dark matter
Nature 521, 7550 (2015). http://www.nature.com/doifinder/10.1038/521017a
Author: Davide Castelvecchi
High-energy particles at centre of Milky Way now within scope of Large Hadron Collider.
Pluto-bound craft hunts for hazardous moons
Nature 521, 7550 (2015). http://www.nature.com/doifinder/10.1038/521014a
Author: Alexandra Witze
Unknown satellites pose danger to New Horizons mission as it journeys to the edge of the Solar System.