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Zwicky 8338: Chandra Finds Remarkable Galactic Ribbon Unfurled
Zwicky 8338
Zwicky 8338
Zwicky 8338

  • A gigantic tail of X-ray emission has been found behind a galaxy plowing through the galaxy cluster Zwicky 8338.

  • With a length of at least 250,000 light years, this is likely the largest such tail ever detected.

  • Scientists used Chandra to discover the tail, study its properties and learn how this X-ray tail affects its cluster environment.

An extraordinary ribbon of hot gas trailing behind a galaxy like a tail has been discovered using data from NASA's Chandra X-ray Observatory, as described in our latest press release. This ribbon, or X-ray tail, is likely due to gas stripped from the galaxy as it moves through a vast cloud of hot intergalactic gas. With a length of at least 250,000 light years, it is likely the largest such tail ever detected. In this new composite image, X-rays from Chandra (blue) have been combined with data in visible light from the Isaac Newton Group of Telescopes (yellow) in the Canary Islands, Spain.

The tail is located in the galaxy cluster Zwicky 8338, which is almost 700 million light years from Earth. The length of the tail is more than twice the diameter of the entire Milky Way galaxy. The tail contains gas at temperatures of about ten million degrees, about twenty million degrees cooler than the intergalactic gas, but still hot enough to glow brightly in X-rays that Chandra can detect.

The researchers think the tail was created as a galaxy known as CGCG254-021, or perhaps a group of galaxies dominated by this large galaxy, plowed through the hot gas in Zwicky 8338. The pressure exerted by this rapid motion caused gas to be stripped away from the galaxy.

In images from Chandra and the NSF's Karl Jansky Very Large Array (not shown in composite), the galaxy CGCG254-021 appears to be moving towards the bottom of the image with the tail following behind. There is a significant gap between the X-ray tail and the galaxy, the largest ever seen. The significant separation between the galaxy and the tail might be evidence that the gas has been completely stripped off the galaxy.

Astronomers were also able to learn more about the interactions of the system by carefully examining the properties of the galaxy and its tail. The tail has a brighter spot, referred to as its "head". Behind this head is the tail of diffuse X-ray emission. The gas in the head may be cooler and richer in elements heavier than helium than the rest of the tail. In front of the head there are hints of a bow shock, similar to a shock wave formed by a supersonic plane and in front of the bow shock is the galaxy CGCG254-021.

Independent research involving observations at infrared wavelengths indicates that CGCG254-021 has the highest mass of all galaxies in Zwicky 8338. The infrared observations, together with models for how galaxies evolve, also imply that among the galaxies in the cluster, CGCG254-021 had by far the highest rate of stars forming in the recent past. However, there is no evidence for new star formation, possibly because gas has been depleted in forming the tail.

The paper describing these results was published in the November 2015 issue of Astronomy and Astrophysics and is also available online. The authors of the paper are Gerrit Schellenberger and Thomas Reiprich from the University of Bonn in Germany. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations. Swift is managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Fast Facts for Zwicky 8338:
Credit  X-ray: NASA/CXC/University of Bonn/G. Schellenberger et al; Optical: INT
Release Date  December 21, 2015
Scale  Image is 11 arcmin across (about 2.1 million light years)
Category  Groups & Clusters of Galaxies
Coordinates (J2000)  RA 18h 11m 26.75s | Dec +49° 49´ 47.35"
Constellation  Hercules
Observation Date  04 Jan 2013
Observation Time  2 hours 13 min.
Obs. ID  15163
Instrument  ACIS
References Schellenberger, G. et al, 2015, A&A, 583, L2; arXiv:1510.03708
Color Code  X-ray: Blue; Optical: Yellow
Distance Estimate  About 680 million light years
distance arrow
Visitor Comments (10)

Interesting, will you be able to tell if the stripped black hole is in fact an Intermediate one?

Posted by John on Saturday, 04.7.18 @ 09:41am

This is way over my pay grade but unbelievably fascinating.

Posted by gin arnold on Saturday, 01.7.17 @ 14:42pm

Excellent work.

Posted by aleena on Wednesday, 06.29.16 @ 19:17pm

Thanks for this Information

Posted by Monica Chrisandtras HINES on Wednesday, 05.4.16 @ 11:58am

A so called black hole is an electromagnetic positron which attracts neutron stars to its center. By centrifugal force the neutron stars are reduced to primal matter, forming the nucleus of an atomic reaction whose explosive force releases primordial particles into the unknown depths of space. Thus is born another galaxy. The proof of this will be found in bumps in the thermal background which reflect the nature of galactic reproduction in the known universe.

Posted by graham harris on Tuesday, 01.26.16 @ 17:02pm

Very interesting. Congratulations.

Posted by Dr.Amalia Kokkinou on Friday, 01.22.16 @ 08:42am

Is there no sign of a small-angle galactic black hole jet?

Posted by Fred E. Howard, Jr. on Monday, 01.4.16 @ 12:03pm

FASCINATING and congratulations on imaging this amazing occurrence. Much appreciation for not only sharing the image to laymen... but also for the tantalizing article

Posted by Elizabeth on Tuesday, 12.29.15 @ 00:39am

Thank You for the newsletter. I don't think we humans are alone in the Universe.

Posted by romano on Tuesday, 12.22.15 @ 21:17pm

Very good article. Easy to follow. Continue the explorations. After all, we must keep observing our universe. How else will we know what's happening out there.

Posted by Noreen Ramkhelawan on Tuesday, 12.22.15 @ 17:08pm

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