Category Astronomy/Space

The green galaxy is caught in the act of transforming from blue to red as its gas supply runs out. Credit: James Trayford/EAGLE/Durham University

An international team used new computer modelling of the Universe to investigate the colours that galaxies have and what those colours might tell us about how galaxies evolve. Using the state-of-the-art EAGLE simulations, the researchers modelled how both the ages and composition of stars in galaxies translate into the colour of light that they produce. These simulations showed that colours of galaxies can also help diagnose how they evolve.

While red and blue galaxies are relatively common, rare green galaxies are likely to be at an important stage in their evolution, when they are rapidly turning from blue – when new stars and planets are being...

Reconstruction of the lensed radio-quiet quasar HS0810+2554 after removing the effects of the lensing. Right: the data from the Karl G. Jansky Very Large Array showing what the source looks like after passage through the lensing galaxy. The images are not to scale – the lensed image appears to be many times larger in the sky than the actual size of the source. Credit: N Jackson/NRAO

Mini-jets of material ejected from a central supermassive black hole appear to be the culprits behind faint radio wave emissions in ‘radio-quiet’ quasars. A study of gravitationally-lensed images of 4 radio-quiet quasars has revealed the structure of these distant galaxies in unprecedented detail...

Annotated image of the Spiderweb Galaxy as seen by the Hubble Space Telescope (optical) in red, the Very Large Array (radio) in green and the Atacama Large Millimeter/submillimeter Array (sub-millimetre) in blue. The red colour shows where the stars are located within this system of galaxies. The radio jet is shown in green, and the position of the dust and water are seen in blue. The water is located to the left and right of the central galaxy. The water to the right is at the position where the radio jet bends down wards. The dust is also seen in blue. The dust is located at the central galaxy and in smaller companion galaxies in its surroundings. Credit: NASA/ESA/HST/STScI/NRAO/ESO/

Astronomers have spotted glowing droplets of condensed water in the distant Spiderweb Galaxy – but not wh...

Two sizes of ripples are evident in this Dec. 13, 2015, view of a top of a Martian sand dune, from NASA’s Curiosity Mars rover. Sand dunes and the smaller type of ripples also exist on Earth. Credit: NASA/JPL-Caltech/MSSS

Some of the wind-sculpted sand ripples on Mars are a type not seen on Earth, and their relationship to the thin Martian atmosphere today provides new clues about the atmosphere’s history. The determination that these mid-size ripples are a distinct type resulted from observations by NASA’s Curiosity Mars rover. 6 months ago, Curiosity made the first up-close study of active sand dunes anywhere other than Earth, at”Bagnold Dunes” on the NW flank of Mount Sharp.

“Earth and Mars both have big sand dunes and small sand ripples, but on Mars, there’s something in between that w...