Look closer at the NASA Hubble Space Telescope image of NGC 1266, and you could mistake it for a spiral galaxy.
But NGC 1266 is no ordinary lenticular.
Using data extending back to October 2023, researchers have traced the odd state of NGC 1266 to a recent minor merger about 500 million years ago.
An active galactic nucleus (AGN) was ignited as gas streamed into the black hole at the center of the galaxy.
The radiation emitted by the black hole powers the winds and jets of gas traveling throughout the galaxy.
Look closer at the NASA Hubble Space Telescope image of NGC 1266, and you could mistake it for a spiral galaxy. There is a bright core with some signs of spiraling arms, but no real spirals extending outward, no graceful spirals unfurling into space. Instead, reddish‑brown dust clumps obscure its features, while distant galaxies shine through the haze like scattered jewels.
About 100 million light-years away in the constellation Eridanus, also known as the Celestial River (opens a new tab), astronomers consider NGC 1266 to be a lenticular galaxy, a special intermediary form between spiral and elliptical galaxies. Typical lenticular galaxies: A classic disk of stars, but not the outer spiral arms and little star formation (due to their lens-like shape and nucleus).
But NGC 1266 is no ordinary lenticular. This is a relatively unusual post-starburst galaxy, caught in the act of transformation. Galaxies in this post-starburst state still contain young stars, but almost no star-forming regions, after having undergone a short period of extremely active star formation. Nearby galaxies of this type represent less than one percent.
Astronomers believe NGC 1266’s unusual state traces back to a minor merger about 500 million years ago. Using data extending back to October 2023, researchers have traced the odd state of NGC 1266 to a recent minor merger about 500 million years ago. This collision triggered a starburst and fed all the stars in the central bulge. An active galactic nucleus (AGN) was ignited as gas streamed into the black hole at the center of the galaxy.
The radiation emitted by the black hole powers the winds and jets of gas traveling throughout the galaxy. These outflows gradually returned star-forming material and some turbulence, suppressing the formation of new stars.
Hubble and other telescopes observe a strong outflow of gas, along with an extremely perturbed interstellar medium. Star formation now seems to have been restricted to the core. Outside that region, starbirth is suppressed by black hole energy, which is powerful enough to remove or shock gas so violently that it cannot rationally collapse into stars.
As the scientists explain, the shockwaves create turbulence that “disturbs the gas and dust between stars enough to stop any remaining matter from gravitationally condensing into infant stars.”
Galaxies like NGC 1266, which have undergone a starburst in the past but are not actively forming stars today, serve as laboratories for astronomers to study the joint evolution of supermassive black holes and their host galaxies, as well as possible astrophysical processes that may inhibit nuclear activity.
NGC 1266 is not just an oddball phone to hit the sky; it is also a snapshot of evolution when galaxies are fully powered to grow and change, made by galactic collisions, black hole activity, and radioactive wind rather than just still collections of stars.
