Using the Atacama Large Millimetre/submillimetre Array (ALMA), a team of astronomers has delved remarkably deep into the heart of a nearby elliptical galaxy to study the motion of a disc of gas encircling the supermassive black hole at its centre. These observations provide one of the most accurate mass measurements to date for a black hole outside of our galaxy.
A near-record 17-billion-solar-mass black hole discovered in a sparse area of the local universe indicates that these monster objects may be more common than once thought. The newly discovered supermassive black hole is in NGC 1600, an elliptical galaxy in the constellation Eridanus some 149 million light-years away.
At first glance, this cosmic kaleidoscope of purple, blue and pink offers a strikingly beautiful — and serene — snapshot of the cosmos. However, this multi-coloured haze actually marks the site of two colliding galaxy clusters, forming a single object known as MACS J0416.1-2403 (or MACS J0416 for short), 4.3 billion light-years away from Earth.
This Hubble image is of the peculiar galaxy NGC 1487, lying about 30 million light-years away. We are witnessing the possible merger of several dwarf galaxies into a new single galaxy. Its appearance is dominated by large areas of bright blue stars, illuminating the patches of gas that gave them life. This burst of star formation may well have been triggered by the merger.
The edge-on spiral galaxy captured in this NASA/ESA Hubble Space Telescope image lies about one billion light-years away in the constellation of Eridanus. In 2003, the galaxy was discovered to possess giant jets of superheated gas emitting in the radio part of the spectrum. These jets have long been associated with the cores of giant elliptical galaxies, but are rare in spirals.