A gorgeous new image from the NASA/ESA Hubble Space Telescope shows NGC 3256, an impressive example of a peculiar galaxy that is actually the relict of a collision of two spiral galaxies that took place in a distant past.
This image, taken with Hubble’s Wide Field Camera 3 (WFC3) and the Advanced Camera for Surveys (ACS) instruments, shows a peculiar galaxy called NGC 3256 — the result of a past galactic merger, which created the galaxy’s distorted appearance. Image credit: NASA / ESA / Hubble.
NGC 3256 is approximately 131 million light-years away from Earth, in the constellation of Vela.
The galaxy is approximately the same size as our own Milky Way Galaxy and belongs to the Hydra-Centaurus Supercluster complex.
NGC 3256 is the relic of a collision between two spiral galaxies, estimated to have occurred 500 million years ago.
It still bears the marks of its tumultuous past in the extended luminous tails that sprawl out around the galaxy. These tails are studded with young blue stars, which were born in the frantic but fertile collision of gas and dust.
When two galaxies merge, individual stars rarely collide because they are separated by such enormous distances, but the gas and dust of the galaxies do interact.
The brightness blooming in NGC 3256’s center gives away its status as a powerful starburst galaxy, host to vast amounts of infant stars born into groups and clusters.
These stars shine most brightly in the far infrared, making the galaxy exceedingly luminous in this wavelength domain. Because of this radiation, it is classified as a luminous infrared galaxy.
NGC 3256 provides an ideal target to investigate starbursts that have been triggered by galaxy mergers.
It holds particular promise to further our understanding of the properties of young star clusters in tidal tails.
As well as being lit up by over 1,000 bright star clusters, the central region of NGC 3256 is also home to crisscrossing threads of dark dust and a large disc of molecular gas spinning around two distinct nuclei — the relics of the two original spiral galaxies. One nucleus is largely obscured, only unveiled in infrared, radio and X-ray wavelengths.
These two initial spirals were gas-rich and had similar masses, as they seem to be exerting roughly equal influence on each other.
Their spiral disks are no longer distinct, and in a few hundred million years time, their nuclei will also merge and the two galaxies will likely become united as a large elliptical galaxy.
