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Bright radio emission from an ultraluminous stellar-mass microquasar in M 31
Done, Chris; Macquart, Jean-Pierre; Della Valle, Massimo +34 more
A subset of ultraluminous X-ray sources (those with luminosities of less than 1040 erg s-1 ref. 1) are thought to be powered by the accretion of gas onto black holes with masses of ~5-20, probably by means of an accretion disk. The X-ray and radio emission are coupled in such Galactic sources; the radio emission originates in…
A black-hole mass measurement from molecular gas kinematics in NGC4526
Sarzi, Marc; Cappellari, Michele; Davis, Timothy A. +2 more
The masses of the supermassive black holes found in galaxy bulges are correlated with a multitude of galaxy properties, leading to suggestions that galaxies and black holes may evolve together. The number of reliably measured black-hole masses is small, and the number of methods for measuring them is limited, holding back attempts to understand th…
Baryons in the relativistic jets of the stellar-mass black-hole candidate 4U1630-47
Miller-Jones, James C. A.; Tzioumis, Tasso; Migliari, Simone +2 more
Accreting black holes are known to power relativistic jets, both in stellar-mass binary systems and at the centres of galaxies. The power carried away by the jets, and, hence, the feedback they provide to their surroundings, depends strongly on their composition. Jets containing a baryonic component should carry significantly more energy than elec…
Supervolcanoes within an ancient volcanic province in Arabia Terra, Mars
Bleacher, Jacob E.; Michalski, Joseph R.
Several irregularly shaped craters located within Arabia Terra, Mars, represent a new type of highland volcanic construct and together constitute a previously unrecognized Martian igneous province. Similar to terrestrial supervolcanoes, these low-relief paterae possess a range of geomorphic features related to structural collapse, effusive volcani…
A rigid and weathered ice shell on Titan
Iess, L.; Zebker, H.; Nimmo, F. +1 more
Several lines of evidence suggest that Saturn's largest moon, Titan, has a global subsurface ocean beneath an outer ice shell 50 to 200 kilometres thick. If convection is occurring, the rigid portion of the shell is expected to be thin; similarly, a weak, isostatically compensated shell has been proposed to explain the observed topography. Here we…
The domination of Saturn's low-latitude ionosphere by ring `rain'
Baines, K. H.; Jones, G. H.; Cowley, S. W. H. +5 more
Saturn's ionosphere is produced when the otherwise neutral atmosphere is exposed to a flow of energetic charged particles or solar radiation. At low latitudes the solar radiation should result in a weak planet-wide glow in the infrared, corresponding to the planet's uniform illumination by the Sun. The observed electron density of the low-latitude…
Pulsed accretion in a variable protostar
Gutermuth, Robert; Muzerolle, James; Furlan, Elise +2 more
Periodic increases in luminosity arising from variable accretion rates have been predicted for some pre-main-sequence close binary stars as they grow from circumbinary disks. The phenomenon is known as pulsed accretion and can affect the orbital evolution and mass distribution of young binaries, as well as the potential for planet formation. Accre…
Solar system: Saturn's ring rain
Connerney, Jack
Saturn's atmosphere bears a latent image of its icy rings, implying that electrically charged bits of water ice are being transported along magnetic-field lines of force from sources in the ring plane to the upper atmosphere. See Letter p.193
Solar system: Saturn's tides control Enceladus' plume
Spencer, John
Data obtained by the Cassini spacecraft show that the plume of ice particles at the south pole of Saturn's moon Enceladus is four times brighter when the moon is farthest away from the planet than when it is closest. See Letter p.182
Gravitational detection of a low-mass dark satellite galaxy at cosmological distance
Vegetti, S.; McKean, J. P.; Auger, M. W. +3 more
The mass function of dwarf satellite galaxies that are observed around Local Group galaxies differs substantially from simulations based on cold dark matter: the simulations predict many more dwarf galaxies than are seen. The Local Group, however, may be anomalous in this regard. A massive dark satellite in an early-type lens galaxy at a redshift …