The tell-tale signs of a galactic merger
The NASA/ESA Hubble Space Telescope has
captured this striking view of spiral galaxy NGC 7714. This galaxy has
drifted too close to another nearby galaxy and the dramatic interaction
has twisted its spiral arms out of shape, dragged streams of material
out into space, and triggered bright bursts of star formation.
NGC 7714 is a spiral galaxy at 100 million light-years from Earth — a relatively close neighbour in cosmic terms.The galaxy has witnessed some violent and dramatic events in its recent past. Tell-tale signs of this brutality can be seen in NGC 7714's strangely shaped arms, and in the smoky golden haze that stretches out from the galactic centre.
So what caused this disfigurement? The culprit is a smaller companion named NGC 7715, which lies just out of the frame of this image — but is visible in the wider-field DSS image. The two galaxies [1] drifted too close together between 100 and 200 million years ago, and began to drag at and disrupt one another’s structure and shape.
As a result, a ring and two long tails of stars have emerged from NGC 7714, creating a bridge between the two galaxies. This bridge acts as a pipeline, funnelling material from NGC 7715 towards its larger companion and feeding bursts of star formation. Most of the star-forming activity is concentrated at the bright galactic centre, although the whole galaxy is sparking new stars.
Astronomers characterise NGC 7714 as a typical Wolf-Rayet starburst galaxy. This is due to the stars within it; a large number of the new stars are of the Wolf-Rayet type — extremely hot and bright stars that begin their lives with dozens of times the mass of the Sun, but lose most of it very quickly via powerful winds.
This Hubble image is a composite of data capturing a broad range of wavelengths, revealing the correlation of the gas clouds and stars in the galaxy. This new picture not only reveals the intricate structure of NGC 7714, but also shows many other objects that are much further away. These background galaxies resemble faint smudges of light, some of them with spiral forms.
Hubble image of NGC 7714
NGC 7714 is a spiral galaxy 100 million light-years from Earth — a relatively close neighbour in cosmic terms.
The galaxy has witnessed some violent and dramatic events in its recent past. Tell-tale signs of this brutality can be seen in NGC 7714's strangely shaped arms, and in the smoky golden haze that stretches out from the galactic centre — caused by an ongoing merger with its smaller galactic companion NGC 7715, which is out of the frame of this image.
Credit:
ESA, NASA
Acknowledgement: A. Gal-Yam (Weizmann Institute of Science)
The galaxy has witnessed some violent and dramatic events in its recent past. Tell-tale signs of this brutality can be seen in NGC 7714's strangely shaped arms, and in the smoky golden haze that stretches out from the galactic centre — caused by an ongoing merger with its smaller galactic companion NGC 7715, which is out of the frame of this image.
Credit:
ESA, NASA
Acknowledgement: A. Gal-Yam (Weizmann Institute of Science)
Wide-field image of NGC 7714 (ground-based image)
This image from the Digitized Sky Survey shows galaxy NGC 7714 and
its surroundings. This galaxy is in the process of merging with its
neighbour NGC 7715, which is also visible in this wide-field image.
Together, these two form the merging pair Arp 284.
In this image, the bright star you can see on the left is around a billion times closer than the galaxy.
Credit:
NASA, ESA, Digitized Sky Survey 2.
Videos
In this image, the bright star you can see on the left is around a billion times closer than the galaxy.
Credit:
NASA, ESA, Digitized Sky Survey 2.
Videos
Panning across NGC 7714
This video pans across the sky near to galaxy NGC 7714 in the
constellation of Pisces, ending on a view of the object itself. This
galaxy is in the process of merging with its neighbour NGC 7715.
Tell-tale signs of this brutal process can be seen in NGC 7714's
strangely shaped arms, and in the smoky golden haze that stretches out
from the galactic centre.
Credit:
NASA, ESA
Music: movetwo
Credit:
NASA, ESA
Music: movetwo
Zooming in on NGC 7714
This video zooms in on NGC 7714, one of a pair of merging galaxies.
The sequence begins with a view of the night sky near the constellation
of Pisces. It then zooms through observations from the Digitized Sky
Survey 2, and ends with a view of the galaxy obtained by Hubble.
Credit:
NASA, ESA, Digitized Sky Survey 2 and A. Fuji
Music: movetwo
Fuente: ESA/Hubble Information Centre
The ESO Education and Public Outreach Department
Credit:
NASA, ESA, Digitized Sky Survey 2 and A. Fuji
Music: movetwo
Fuente: ESA/Hubble Information Centre
The ESO Education and Public Outreach Department
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