Kamal Ghorui
Astronomers have identified a nearby galaxy whose central activity seems to be changing its long-term future. This galaxy, VV 340a, contains a supermassive black hole, which is sucking matter in and producing a strong jet that goes outward through its disc. Scientists have revealed that the jet is actually disrupting the gas that could potentially form stars. Moreover, the energy does not remain trapped in the galaxy’s core, instead radiating to a vast area.Scientists discovered that the behaviour of VV 340a is caused by the supermassive black hole at its centre, which not only attracts matter inward but also produces an energetic jet that extends outward along its disc. Moreover, the jet actively hinders the gas, which would typically fuel star formation, from transforming into stars. In fact, the energy leaves the galaxy’s nucleus and travels to a vast region.
This galaxy is being drained from the inside by a black hole
At the heart of VV 340a sits an active galactic nucleus powered by a feeding supermassive black hole. While black holes are best known for their gravity, this one also produces a focused stream of energetic material. The jet is made of fast-moving, ionised gas launched from the region close to the black hole. Instead of remaining narrow and straight, it expands its reach as it moves outward. This outward pressure is strong enough to disturb gas clouds that normally stay cool and dense. Those clouds are essential for forming new stars. Over time, their disruption changes the balance of the entire galaxy.
A jet that slowly shifts its aim
What sets this system apart is the motion of the jet itself. Rather than holding a fixed direction, it wobbles as it travels. Astronomers describe this as precession, where the jet sweeps out a cone and forms a spiral pattern. The effect is similar to a spinning top that tilts as it turns. This motion allows the jet to touch far more of the galaxy than a straight beam would. Gas that might otherwise escape disturbance ends up heated or pushed aside. Researchers say this is the clearest example yet of such a jet operating on the scale of a disk galaxy.
Star forming gas pushed out of reach
Research, “ A precessing jet from an active galactic nucleus drives gas outflow from a disk galaxy”, suggests the impact is substantial. The team estimates that gas is being expelled at a rate close to twenty solar masses each year. That is gas no longer available to collapse into new stars. The material is also unusually hot and highly ionised, a state more often seen very close to black holes. In VV 340a, this gas extends well beyond the core. Infrared observations were key in tracing it, as dust blocks much of the visible light. The loss of cold gas does not shut star formation off instantly, but it steadily weakens the process.
Webb and radio telescopes reveal hidden structure
The study relied on a mix of instruments to piece together what is happening. The James Webb Space Telescope revealed warm gas and dust buried deep inside the galaxy. Radio observations from the Very Large Array mapped the jet’s shape and motion. Data from the Keck II telescope added detail at optical wavelengths, while ALMA traced colder material at submillimetre scales. Each set of observations filled gaps left by the others. Together, they showed how the jet, the gas, and the surrounding structure are linked rather than acting in isolation.
A disk galaxy under unusual pressure
Jets of this kind are often associated with massive elliptical galaxies. VV 340a is different. It is a disc galaxy, with a flatter shape and organised rotation. Seeing a precessing jet operate so effectively in this environment challenges earlier assumptions. The jet does not simply punch through and escape. It lingers, interacts, and spreads energy sideways. That prolonged contact appears to matter more than raw power alone. It suggests that geometry and motion play a role in how black holes regulate their hosts.
Galactic change without a sudden ending
The researchers are careful not to frame the process as instant destruction. VV 340a is not empty of stars, nor is it about to vanish. Instead, the galaxy seems to be slowly redirected. Star formation may continue at a reduced pace or shift to regions less affected by the jet. What the system shows is how influence can build quietly. Over long timescales, that steady pressure can reshape a galaxy’s future, not with a single blow, but with persistence.
