The James Webb Space Telescope (JWST) continues to unravel the mysteries of the cosmos, offering stunning insights into the forces that shape galaxies.
A recent study led by Prof. Dasyra of the National and Kapodistrian University of Athens has provided a fresh perspective on how supermassive black holes influence galaxy evolution by expelling interstellar gas. The study, focused on the nearby galaxy IC5063, showcases JWST’s remarkable capabilities and sheds light on the dynamic relationship between black holes and their host galaxies.
Observing IC5063
Supermassive black holes, like the one at the center of IC5063, are not just passive entities; they actively shape their surroundings. In this galaxy, jets—high-speed streams of particles traveling near the speed of light—emerge from the black hole, altering the interstellar environment. Using JWST’s Mid-Infrared Instrument (MIRI), researchers captured highly detailed images and spectra from the region surrounding the galaxy’s nucleus, covering a span equivalent to one-third the distance between the Sun and the center of the Milky Way.
The findings revealed over ten distinct regions within IC5063 where gas is being pushed out by the powerful black hole jets, nearly doubling the previously known areas of such activity. Some of these winds move at velocities so extreme that they can escape the galaxy’s gravitational grip. This process depletes the galaxy of gas necessary for star formation, effectively delaying the creation of new stars.
Bow Shocks and Turbulent Gas
The study uncovered evidence of past jet activity in IC5063 through the detection of bow shocks—vast, bow-shaped structures formed as jet particles collide with the interstellar medium at supersonic speeds. These shocks compress, heat, and accelerate the surrounding gas, analogous to the sonic booms produced by high-speed aircraft in Earth’s atmosphere.
Remarkably, these bow shocks span an astonishing distance of 300 parsecs (pc), equivalent to six billion times the distance between JWST and Earth. Even more surprising is their location, far beyond the nucleus of IC5063 where radio emissions from the jets are detected. This suggests that the galaxy’s central black hole has undergone multiple episodes of jet activity, shaping its environment over time.
The Role of Molecular Hydrogen
A key discovery in this study is the bright emission of molecular hydrogen (H₂) within the bow shocks. This emission provides evidence of energy transfer from the jets to dense gas, causing turbulence and heating. Interestingly, this process can have opposing effects: while it can prevent gas clouds from collapsing to form stars, it can also compress the gas in a way that might trigger star formation under certain conditions.
Understanding phenomena like those observed in IC5063 is crucial for piecing together the broader puzzle of galaxy evolution. During earlier cosmic epochs, galaxies contained far greater amounts of gas, making the impact of black hole jets even more profound. By studying galaxies like IC5063, scientists gain valuable insight into how black holes likely shaped the structure and growth of galaxies in the distant past.