The tell-tale signs of a galactic merger

PR Image heic1503a Hubble image of NGC 7714

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.

Notes for editors

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

[1] The interacting pair formed by NGC 7714 and NGC 7715 is named Arp 284.

More information

Credit: ESA, NASA

Acknowledgement: A. Gal-Yam (Weizmann Institute of Science)

Links
Images of Hubble

Contacts

Georgia Bladon
Hubble/ESA
Garching, Germany
Tel: +49-89-3200-6855

Email: gbladon@partner.eso.org

Media Contact

Georgia Bladon Hubble/ESA

All latest news from the category: Physics and Astronomy

This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.

innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.

Back to home

Comments (0)

Write a comment

Newest articles

A new puzzle piece for string theory research

Dr. Ksenia Fedosova from the Cluster of Excellence Mathematics Münster, along with an international research team, has proven a conjecture in string theory that physicists had proposed regarding certain equations….

Climate change can cause stress in herring larvae

The occurrence of multiple stressors undermines the acclimatisation strategies of juvenile herring: If larvae are exposed to several stress factors at the same time, their ability to respond to these…

Making high-yielding rice affordable and sustainable

Plant biologists show how two genes work together to trigger embryo formation in rice. Rice is a staple food crop for more than half the world’s population, but most farmers…