Blogarchiv
Astronomie - HUBBLE CAPTURES GALAXIES GHOSTLY GAZE

29.10.2019

low-stsci-h-p1951a-k-1340x520

MENACING-LOOKING 'FACE' FORMED BY TITANIC SMASHUP BETWEEN TWO GALAXIES

The universe is a bubbling cauldron of matter and energy that have mixed together over billions of years to create a witches' brew of birth and destruction.

Firestorms of star birth sweeping across the heavens. Dying stars rattling the very fabric of space in titanic explosions. Death Star-like beams of energy blasting out of overfed black holes at nearly the speed of light. Large galaxies devouring smaller companions, like cosmic Pac-Men. Colossal collisions between galaxies flinging stars around like breaking pool balls. Hubble has seen them all.

This compulsive mayhem in space can produce weird-looking shapes that resemble creepy creatures seemingly conjured up in stories of the paranormal. Among them is the object in this new Hubble image.

The snapshot reveals what looks like an uncanny pair of glowing eyes glaring menacingly in our direction. The piercing "eyes" are the most prominent feature of what resembles the face of an otherworldly creature. This frightening object is actually the result of a titanic head-on collision between two galaxies.

Each "eye" is the bright core of a galaxy, the result of one galaxy slamming into another. The outline of the face is a ring of young blue stars. Other clumps of new stars form a nose and mouth.

The system is catalogued as Arp-Madore 2026-424, from the Arp-Madore "Catalogue of Southern Peculiar Galaxies and Associations."

Although galaxy collisions are common—especially back in the young universe—most of them are not head-on smashups, like the collision that likely created this Arp-Madore system. The violent encounter gives the system an arresting "ring" structure for only a short amount of time, about 100 million years. The two galaxies will merge completely in about 1 to 2 billion years, hiding their messy past.

----

When astronomers peer deep into space, they don't expect to find something staring back at them.

In this new Hubble Space Telescope image, an uncanny pair of glowing eyes glares menacingly in our direction. The piercing "eyes" are the most prominent feature of what resembles the face of an otherworldly creature.

But this is no ghostly apparition. Hubble is looking at a titanic head-on collision between two galaxies.

Each "eye" is the bright core of a galaxy, one of which slammed into another. The outline of the face is a ring of young blue stars. Other clumps of new stars form a nose and mouth. The entire system is catalogued as Arp-Madore 2026-424 (AM 2026-424), from the Arp-Madore "Catalogue of Southern Peculiar Galaxies and Associations."

Although galaxy collisions are common—especially back in the young universe—most of them are not head-on smashups, like the collision that likely created this Arp-Madore system. The violent encounter gives the system an arresting "ring" structure for only a short amount of time, about 100 million years. The crash pulled and stretched the galaxies' disks of gas, dust, and stars outward. This action formed the ring of intense star formation that shapes the nose and face.

Ring galaxies are rare; only a few hundred of them reside in our larger cosmic neighborhood. The galaxies have to collide at just the right orientation to create the ring. The galaxies will merge completely in about 1 to 2 billion years, hiding their messy past.

The side-by-side juxtaposition of the two central bulges of stars from both galaxies also is unusual. Because the bulges that make the eyes appear to be the same size, it is evidence that two galaxies of nearly equal proportions were involved in the crash, rather than more common collisions where small galaxies are gobbled up by their larger neighbors.

Hubble observed this unique system as part of a "snapshot" program that takes advantage of occasional gaps in the telescope's observing schedule to squeeze in additional pictures.

Astronomers plan to use this innovative Hubble program to take a close look at many other unusual interacting galaxies. The goal is to compile a robust sample of nearby interacting galaxies, which could offer insight into how galaxies grew over time through galactic mergers. By analyzing these detailed Hubble observations, astronomers could then choose which systems are prime targets for follow-up with NASA's James Webb Space Telescope, scheduled to launch in 2021.

Astronomer Halton Arp published his compendium of 338 unusual-looking interacting galaxies in 1966. He later partnered with astronomer Barry Madore to extend the search for unique galactic encounters in the southern sky. Several thousand galaxies are listed in that survey, published in 1987.

The Hubble image of AM 2026-424 was taken June 19, 2019, in visible light by the Advanced Camera for Surveys. The system resides 704 million light-years from Earth.

stsci-h-p1951b-d-1280x720

Quelle: NASA

328 Views