Institute of Astronomy

Astronomy News

Bright spots on Ceres could be active ice

26 March 2015 - 10:17am

Bright spots on Ceres could be active ice

Nature 519, 7544 (2015).

Author: Alexandra Witze

Early data from Dawn spacecraft bring scientists closer to clearing up mystery about dwarf planet.

Wind from the black-hole accretion disk driving a molecular outflow in an active galaxy

26 March 2015 - 10:16am

Wind from the black-hole accretion disk driving a molecular outflow in an active galaxy

Nature 519, 7544 (2015). doi:10.1038/nature14261

Authors: F. Tombesi, M. Meléndez, S. Veilleux, J. N. Reeves, E. González-Alfonso & C. S. Reynolds

Powerful winds driven by active galactic nuclei are often thought to affect the evolution of both supermassive black holes and their host galaxies, quenching star formation and explaining the close relationship between black holes and galaxies. Recent observations of large-scale molecular outflows in ultraluminous infrared galaxies support this quasar-feedback idea, because they directly trace the gas from which stars form. Theoretical models suggest that these outflows originate as energy-conserving flows driven by fast accretion-disk winds. Proposed connections between large-scale molecular outflows and accretion-disk activity in ultraluminous galaxies were incomplete because no accretion-disk wind had been detected. Conversely, studies of powerful accretion-disk winds have until now focused only on X-ray observations of local Seyfert galaxies and a few higher-redshift quasars. Here we report observations of a powerful accretion-disk wind with a mildly relativistic velocity (a quarter that of light) in the X-ray spectrum of IRAS F11119+3257, a nearby (redshift 0.189) optically classified type 1 ultraluminous infrared galaxy hosting a powerful molecular outflow. The active galactic nucleus is responsible for about 80 per cent of the emission, with a quasar-like luminosity of 1.5 × 1046 ergs per second. The energetics of these two types of wide-angle outflows is consistent with the energy-conserving mechanism that is the basis of the quasar feedback in active galactic nuclei that lack powerful radio jets (such jets are an alternative way to drive molecular outflows).

Galaxy formation: When the wind blows

26 March 2015 - 10:16am

Galaxy formation: When the wind blows

Nature 519, 7544 (2015). doi:10.1038/519423a

Authors: James E. Geach

Astronomical observations of a luminous galaxy that has a central, mass-accreting supermassive black hole reveal how such entities launch and propel gas through galaxies at high speeds. See Letter p.436

Planetary science: Rings proposed for orbiting rock

26 March 2015 - 10:13am

Planetary science: Rings proposed for orbiting rock

Nature 519, 7544 (2015). doi:10.1038/519393a

An asteroid-sized rock orbiting between Saturn and Uranus may have a system of rings.Amanda Bosh of the Massachusetts Institute of Technology in Cambridge and her team observed the minor planet 2060 Chiron passing in front of a star, using NASA's Infrared Telescope Facility on

Mars rover detects 'useful nitrogen'

26 March 2015 - 10:12am

The Curiosity rover makes a detection of nitrogen compounds which provide further evidence that ancient Mars would have been a habitable world.

Just one week left to submit a talk or poster abstract for NAM 2015! This is a...

25 March 2015 - 10:18am
Just one week left to submit a talk or poster abstract for NAM 2015!

This is a great opportunity to share your research with a wide range of researchers, at the UK's biggest professional astronomy conference.A wide range of scientific topics are included.

The deadline is 1 April.

National Astronomy Meeting 2015
National Astronomy Meeting 2015

Wrecking ball Jupiter paved way for Earth

25 March 2015 - 10:15am

Jupiter may have ploughed through the early solar system, driving some of the first planets to a fiery death in the sun – and cleared room for planets like Earth

Colliding Stars Explain Enigmatic Seventeenth Century Explosion

24 March 2015 - 8:58am
New observations made with APEX and other telescopes reveal that the star that European astronomers saw appear in the sky in 1670 was not a nova, but a much rarer, violent breed of stellar collision. It was spectacular enough to be easily seen with the naked eye during its first outburst, but the traces it left were so faint that very careful analysis using submillimetre telescopes was needed before the mystery could finally be unravelled more than 340 years later. The results appear online in the journal Nature on 23 March 2015.

The RAS and Institute of Physics back the UK bid for the HQ of the Square Kilome...

24 March 2015 - 8:56am
The RAS and Institute of Physics back the UK bid for the HQ of the Square Kilometre Array to be at Jodrell Bank

RAS and IOP back UK bid for HQ of world’s largest telescope
The Royal Astronomical Society (RAS) and the Institute of Physics (IOP) have responded to the decision of the Square Kilometre Array (SKA) Organisation to extend its selection process to decide on where to site the permanent headquarters of the array

Australia finds 'huge asteroid impact'

24 March 2015 - 8:46am

Scientists in central Australia discover what they say is a 400km-wide underground asteroid crater - the largest impact area ever found.

Awesome photos from Europe's biggest solar eclipse

23 March 2015 - 10:27am

Umbraphiles in the UK saw the biggest solar eclipse in 16 years, but the European Space Agency beat the clouds and got a spectacular view from space

Quasar backlighting gives weight to Andromeda galaxy

23 March 2015 - 10:26am

Astronomers find 40 billion suns' worth of gas hiding in our neighbouring galaxy's halo – and get insight into how galaxies collect material over time

Rosetta makes first detection of molecular nitrogen at a comet

20 March 2015 - 12:20pm

ESA's Rosetta spacecraft has made the first measurement of molecular nitrogen at a comet, providing clues about the temperature environment in which Comet 67P/Churyumov-Gerasimenko formed.

NASA’s SOFIA Finds Missing Link Between Supernovae and Planet Formation

20 March 2015 - 12:20pm

Using NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA), an international scientific team discovered that supernovae are capable of producing a substantial amount of the material from which planets like Earth can form.

The Mystery of Nanoflares

20 March 2015 - 12:20pm
Tiny solar flares on the sun seem to be having an outsized effect on the temperature of the sun's atmosphere. A NASA telescope designed to study black holes may be able to crack the mystery of "nanoflares."

NASA Spacecraft Detects Aurora and Mysterious Dust Cloud around Mars

19 March 2015 - 10:40am

NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft has observed two unexpected phenomena in the Martian atmosphere: an unexplained high-altitude dust cloud and aurora that reaches deep into the Martian atmosphere.

Weird aurora and dust cloud found on new Mars mission

19 March 2015 - 10:39am

Since its arrival in orbit around the Red Planet in October, the MAVEN mission has already found mysterious aurora and a dust cloud that researchers are scrambling to explain

Bright spots on Ceres could be water volcanoes

19 March 2015 - 10:38am
Images taken by NASA's Dawn spacecraft show that a mysterious bright spot on dwarf planet Ceres could be a plume of water spurting from a deep, icy crater

A dusty, normal galaxy in the epoch of reionization

19 March 2015 - 10:38am

A dusty, normal galaxy in the epoch of reionization

Nature 519, 7543 (2015). doi:10.1038/nature14164

Authors: Darach Watson, Lise Christensen, Kirsten Kraiberg Knudsen, Johan Richard, Anna Gallazzi & Michał Jerzy Michałowski

Candidates for the modest galaxies that formed most of the stars in the early Universe, at redshifts z > 7, have been found in large numbers with extremely deep restframe-ultraviolet imaging. But it has proved difficult for existing spectrographs to characterize them using their ultraviolet light. The detailed properties of these galaxies could be measured from dust and cool gas emission at far-infrared wavelengths if the galaxies have become sufficiently enriched in dust and metals. So far, however, the most distant galaxy discovered via its ultraviolet emission and subsequently detected in dust emission is only at z = 3.2 (ref. 5), and recent results have cast doubt on whether dust and molecules can be found in typical galaxies at z ≥ 7. Here we report thermal dust emission from an archetypal early Universe star-forming galaxy, A1689-zD1. We detect its stellar continuum in spectroscopy and determine its redshift to be z = 7.5 ± 0.2 from a spectroscopic detection of the Lyman-α break. A1689-zD1 is representative of the star-forming population during the epoch of reionization, with a total star-formation rate of about 12 solar masses per year. The galaxy is highly evolved: it has a large stellar mass and is heavily enriched in dust, with a dust-to-gas ratio close to that of the Milky Way. Dusty, evolved galaxies are thus present among the fainter star-forming population at z > 7.

Five Solar System sights NASA should visit

19 March 2015 - 10:36am

Five Solar System sights NASA should visit

Nature 519, 7543 (2015).

Author: Alexandra Witze

US planetary scientists dream up voyages of discovery, from Venus mappers to asteroid tours.