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| What looks like a celestial hummingbird is really the result of a collision between a spiral and an elliptical galaxy at a whopping 326 million light- years away. The flat disk of the spiral NGC 2936 is warped into the profile of a bird by the gravitational tug of the companion NGC 2937 [Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)] |
The remnants of its spiral structure can still be seen -- the former galactic bulge now forms the "eye" of the penguin, around which it is still possible to see where the galaxy's pinwheeling arms once were. These disrupted arms now shape the cosmic bird's "body" as bright streaks of blue and red across the image. These streaks arch down towards NGC 2936's nearby companion, the elliptical galaxy NGC 2937, visible here as a bright white oval. The pair show an uncanny resemblance to a penguin safeguarding its egg.
The effects of gravitational interaction between galaxies can be devastating. The Arp 142 pair are close enough together to interact violently, exchanging matter and causing havoc.
Galaxies spend most of their life drifting through the cosmic expanse in isolation. But, every so often, two unfortunate galaxies stray a little too close to one another — as is the case with Arp 142. Showcased in a stunning new image from Hubble, these two galaxies uncannily resemble a penguin guarding its egg. The galaxies are in middle of a violent merger, with clouds of gas and dust colliding at breakneck speeds and triggering bursts of star formation [Credit: ESA/Hubble]
In the upper part of the image are two bright stars, both of which lie in the foreground of the Arp 142 pair. One of these is surrounded by a trail of sparkling blue material, which is actually another galaxy. This galaxy is thought to be too far away to play a role in the interaction -- the same is true of the galaxies peppered around the body of NGC 2936. In the background are the blue and red elongated shapes of many other galaxies, which lie at vast distances from us -- but which can all be seen by the sharp eye of Hubble.
This pair of galaxies is named after the American astronomer Halton Arp, the creator of the Atlas of Peculiar Galaxies, a catalogue of weirdly-shaped galaxies that was originally published in 1966. Arp compiled the catalogue in a bid to understand how galaxies evolved and changed shape over time, something he felt to be poorly understood. He chose his targets based on their strange appearances, but astronomers later realised that many of the objects in Arp's catalogue were in fact interacting and merging galaxies.
Source: European Space Agency (ESA) [June 20, 2013]