ring galaxy

(redirected from Ring galaxies)

ring galaxy

A very rare type of galaxy that has the form of an elliptical ring either with a massive nucleus, often off-center, or with little or no luminous material visible in its interior. In many cases there is a small satellite galaxy devoid of interstellar gas. The ring configuration is thought to be unstable and it has been suggested that these systems may represent the after-effects of a collision between two galaxies.

ring galaxy

[′riŋ ‚gal·ik·sē]
(astronomy)
A class of galaxy whose ringlike structure has clumps of ionized hydrogen clouds on its periphery, may have a nucleus of stars, and is usually accompanied by a small galaxy; probably formed when a small galaxy crashes through the disk of a spiral galaxy.
References in periodicals archive ?
The study, titled "The X-Ray Luminosity Function of Ultra Luminous X-Ray Sources in Collisional Ring Galaxies," was recently published in (http://iopscience.iop.org/article/10.3847/1538-4357/aacb34/meta) the Astrophysical Journal.
Among the topics are a forming polar ring galaxy in the deep field of the Fornax Cluster, star formation laws in various types of galaxies and the case of polar ring galaxies, kinematic transitions and streams in galaxy halos, and shapes and colors of galaxies from school to science.
These objects, called collisional ring galaxies, are relatively rare in our cosmic neighbourhood.
Either way, there's no sign of ring galaxies being aligned in the sky.
Everything is there: from stately spirals and giant ellipticals in different classes, to barred, edge-on, ring galaxies, irregular's and the more unfamiliar early types of leniculars.
Although collisional ring galaxies are rare, there are several excellent examples to choose from at this time of year.
With the help of a state-of-the=art infrared detector, they have begun to reconstruct the violent past of this intriguing structure -- dubbed the Cartwheel -- and other so-called ring galaxies. The gradual shift in color seen in these galaxies, from their nucleus on out, offers an unusual peek into the history of star formation enabling astronomers to test models of stellar evolution in an entirely new way, says Philip N.
"But in the ring galaxies," he adds, "we're actually seeing the sequence of events separated.
One of the most geometrically perfect of the 30 or so known ring galaxies, the Cartwheel, located some 270 million light-years from Earth, contains both an inner and an outer ring, with spiral "spokes" of stars connecting the two.
How ring galaxies form is currently a hot research topic.
Several other ring galaxies can be found in the autumn skies.
Smaller and more compact than the previous ring galaxies, it has a bright, nearly stellar core surrounded by a diffuse oval halo.