Elliptical galaxies and globular clusters are fascinating. They don't spin or flatten but remain a very loose 'ball' of stars and maintain that shape over millions of years. They essentially look the same but the elliptical galaxy holds many, many more stars than the globular cluster. Both are rather benign with a supernova very rare, due to few of those huge stars that do that. There is another similar object called a dwarf spheroidal galaxy. This is essentially a diffuse globular cluster.
I posted about Globular clusters on June 4, in two parts/posts.The first was about the orbit of a cluster around the Milky Way. The second was about the motions of the stars within the cluster. In some of the clusters the stars are moving radially. An oscillating linear motion cannot be explained by gravity.
These similar objects: ellipticals, globulars, and dwarf spherical galaxies need EUT to explain them. Gravity cannot.
Descriptions of ellipticals usually rely on dark matter which always means astronomers are ignoring electromagnetic effects and they cannot find enough visible mass to provide the only force available to them which is gravity.
Most elliptical galaxies are composed of older, low-mass stars, with a sparse interstellar medium and minimal star formation activity, and they tend to be surrounded by large numbers of globular clusters. Elliptical galaxies are believed to make up approximately 10%–15% of galaxies in the Virgo Supercluster, and they are not the dominant type of galaxy in the universe overall. They are preferentially found close to the centers of galaxy clusters.
The characteristics of elliptical galaxy are unique that you can distinguish them from the other galaxies (normal spiral, barred spiral, and irregular; a lenticular is a class between ellipticals and spirals). Elliptical has the dominant radial motion of stars. Moreover, the galaxy has the red color due to the presence of old stellar stars. The center of the galaxy has a supermassive black hole.
The smallest, the dwarf elliptical galaxies, may be no larger than a typical globular cluster, but contain a considerable amount of dark matter not present in clusters.
The radial motion in an elliptical is also observed in globular clusters.
It is interesting both a black hole (provides much gravity from an invisible point) and dark matter (dispersed invisible stuff that has gravity ) are mentioned. This means cosmologists are very far from understanding them when needing exotic sources of invisible gravity.
The formation of elliptical galaxies cannot be explained. Wikipedia has 'it is believed' 'researchers have speculated' in descriptions.
Dwarf Spheroidal Galaxy:
A dwarf spheroidal galaxy (dSph) is a term in astronomy applied to small, low-luminosity galaxies with very little dust and an older stellar population. They are found in the Local Group as companions to the Milky Way and to systems that are companions to the Andromeda Galaxy. While similar to dwarf elliptical galaxies in appearance and properties such as little to no gas or dust or recent star formation, they are approximately spheroidal in shape and generally have lower luminosity.
Despite the radii of dSphs being much larger than those of globular clusters, they are much more difficult to find due to their low luminosities and surface brightnesses. Dwarf spheroidal galaxies have a large range of luminosities, and known dwarf spheroidal galaxies span several orders of magnitude of luminosity. Their luminosities are so low that Ursa Minor, Carina, and Draco, the known dwarf spheroidal galaxies with the lowest luminosities, have mass-to-light ratios (M/L) greater than that of the Milky Way.
Apparently a dwarf spheroidal galaxy is just a globular cluster but a larger volume for its stars results in low luminosity.
There is another rare galaxy type called a ring galaxy. This appears as a galactic core, or perhaps an elliptical, with a ring of stars around it. I posted about these on June 2.
These descriptions imply this scenario:
a) nearly every large galaxy cluster has a large elliptical galaxy at its center.
b) Around that elliptical there will be a variety of other types, from a lenticular, which is essentially a spiral core with its halo and a dust lane but no arms, to a spiral (each having a different configuration of arms), to an irregular (which is many stars but with no defined structure like the other types).
c) Globular clusters proliferate in the cluster - around the elliptical and in smaller numbers around the other types but larger spirals generally have more globular clusters than smaller galaxies.
d) When looking at many galaxy clusters there is usually no apparent alignment pattern in the group.
e) Even with so many 'clusters' of stars the galaxy cluster remains dispersed. When viewing many images of galaxy clusters a case where galaxies are seen to be merging are rare. Astronomers sometimes describe mergers and collisions but each case is usually a galaxy with an unusual appearance so with no other easy explanation available it is just described as an odd mix of others. A separation can look like a merge. The force of gravity is simply unable to collapse a cluster of galaxies holding billions or even trillions of stars. More than gravity is involved in a cluster's stability with the presence of electric fields capable of attraction or repulsion in a universe that is almost 100% plasma.
e) when jets or arcs are observed the galaxy is usually an elliptical.
Though the elliptical seems benign, in distant galaxy clusters where arcs are seen those arcs are always around the central elliptical in the cluster. These clusters also indicate an active intergalactic medium with X-ray emissions. I posted about these arcs and rings on June 2. The mechanism for this distant electrical arc or ring around an elliptical is unknown.
Cosmologists do not have an explanation for how an elliptical galaxy or a globular cluster forms.
The observation that there is always a large elliptical galaxy at the center of every large galaxy cluster makes them rather critical in understanding how the universe evolves.
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