Credit: ESO/A. Alonso-Herrero et al.; ALMA (ESO/NAOJ/NRAO
This ESO Picture of the Week shows the centre of a galaxy named NGC 5643. This galaxy is located 55 million light-years from Earth in the constellation of Lupus (The Wolf), and is known as a Seyfert galaxy. Seyfert galaxies have very luminous centres — thought to be powered by material being accreted onto a supermassive black hole lurking within — that can also be shrouded and obscured by clouds of dust and intergalactic material.
As a result, it can be difficult to observe the active centre
of a Seyfert galaxy. NGC 5643 poses a further challenge; it is viewed
at a high inclination, making it even trickier to view its inner
workings. However, scientists have used the Atacama Large Millimeter/submillimeter Array (ALMA) together with archival data from the Multi Unit Spectroscopic Explorer (MUSE) instrument on ESO’s Very Large Telescope to reveal this view of NGC 5643 — complete with energetic outflowing ionised gas pouring out into space.
These
impressive outflows stretch out on either side of the galaxy, and are
caused by matter being ejected from the accretion disc of the
supermassive black hole at NGC 5643’s core. Combined, the ALMA and VLT
data show the galaxy’s central region to have two distinct components: a
spiraling, rotating disc (visible in red) consisting of cold molecular
gas traced by carbon monoxide, and the outflowing gas, traced by ionised
oxygen and hydrogen (in blue-orange hues) perpendicular to the inner
nuclear disc.
