A recent observation from the
Hubble Space Telescope shows the spiral galaxy NGC 4388 in the process of shedding a luminous stream of gas. This remarkable event occurs as it moves through an exceptionally dense environment.
Located about 60 million light-years away in the constellation of Virgo, NGC 4388 is a member of the eponymous Virgo Cluster, a massive grouping that exerts a strong influence on its constituents. Its proximity to other galaxies creates unique conditions, where invisible forces gradually work on stellar structures.
A side-on view of the spiral galaxy NGC 4388 shows a stream of luminous gas being stripped from its core as it traverses the Virgo Cluster.
Credit: ESA/Hubble & NASA, S. Veilleux, J. Wang, J. Greene
Observed almost edge-on from Earth, this particular orientation reveals a previously unseen detail: a plume of gas escaping from the galaxy's center. This stream stretches outward (the bluish stream at the bottom right of the image), moving away from the galactic disk. This observation raises new questions about the mechanisms at play in such regions of the cosmos.
Between the galaxies in the cluster, a very hot and tenuous gas, known as the intracluster medium, fills the space. Moving at high speed, NGC 4388 plows through this medium, which exerts significant pressure on its own gas. This interaction gradually strips away material, leaving a luminous trail behind the moving galaxy. This process alters the composition and fate of NGC 4388.
The glow of this gas appears to come from two main sources. Near the galactic center, a supermassive black hole heats the surrounding matter, emitting radiation that excites the gas. Farther out, shock waves generated by the collision with the intracluster medium also contribute to its luminosity. These combined phenomena make the stream observable from our planet.
The latest data from
Hubble, which combines multiple wavelengths, have allowed this gaseous cloud to be observed with increased clarity.