'Armless spiral galaxies' is a phrase used to describe lenticular galaxies.
There is a center bulge in lenticular galaxies but no spiral arms. The only difference between spiral and lenticular galaxies is that a lenticular galaxy will have a significantly larger bulge-to-disk ratio than traditional faded spiral galaxies (anemic spiral galaxies).
It can be difficult to distinguish the difference between a lenticular galaxy and an E0 galaxy if the central bulge is not extremely bright.
An S lenticular galaxy is the Cartwheel Galaxy, also known as ESO 350-40 and PGC 2248. An example of an Sb lenticular galaxy is NGC 2787. Messier 85, also known as NGC 4382, is a lenticular galaxy in the Sa class.
Nearly 75 lenticular galaxies have been discovered. NGC 6861 is a lenticular galaxy discovered by James Dunlop, a Scottish astronomer, in 1826.
What is a lenticular galaxy?
In morphological categorization schemes, a lenticular galaxy (denoted S0) is a form of the galaxy that lies halfway between an elliptical galaxy (denoted as E) and a spiral galaxy.
Their rotational velocity is thought to balance the gravitational attraction of the material within any radius. The stability of such a galaxy is attributed to the average circular motion of stars in the disc, which is known as rotation support.
Lenticular galaxies are categorized as normal disk galaxies (S0 or SB0) if they feature a bar of stars, gas, and dust running across the nucleus and are intermediate in the Hubble classification scheme between elliptical and spiral forms.
They are disk structure-shaped with a central bulge component, similar to spiral galaxies, although they contain less gas and dust than elliptical galaxies.
Although it has a large-scale disc, it lacks large-scale spiral arms. Lenticular galaxies are actually disc galaxies with very few continuing star formation theories because most of their interstellar matter has been used up or lost.
They can, however, have a lot of dust in their discs. Due to this, they're mostly made up of retired entities (like an elliptical galaxy).
Lenticular as well as elliptical galaxies have shared traits, such as scale relations and spectral features, despite their physical variances. Both galaxies can be classified as early-type galaxies which are quietly developing in the local Universe.
ES galaxies, along with intermediate-scale discs, connect E galaxies to S0 galaxies. Spiral galaxy data mostly deals with a central bulge surrounded by flattened disk components with no spiral pattern.
Lenticular Galaxy Location
A lenticular galaxy is a disk galaxy that lies between the elliptical and spiral categories. They share features with the other two disk galaxies.
The galaxies will have a central bulge and discs, but they will lack the arms that spiral galaxies like our own, the Milky Way, have. The galaxy is named for the fact that it resembles a lens, with a bulge in the center but no projecting arms outwards it.
They will have a spiral-shaped disk nature with a pronounced protrusion.
Lenticular galaxies (also known as S0 galaxies) feature a lens-like form when viewed from the edge. They have a structure that looks to be halfway between elliptical galaxies and spiral galaxies and is labeled S0 galaxies or SB0 galaxies on the Hubble classification diagram.
Some lenticular galaxies, like spiral galaxies, feature a bar. We reside in one of the Milky Way's arms, which is a massive spiral galaxy.
The Discovery Of A Lenticular Galaxy
At least one of the lenticular creation ideas may have been influenced by Hubble's seminal study on galaxies. In essence, he suggested that lenticular galaxies formed from elliptical galaxies as a transition to a spiral (or barred spiral) galaxy, although one contemporary hypothesis proposes that the opposite is true.
It's likely that lenticular galaxies are just ancient, fading spiral galaxies with disk-like forms and central bulges but no distinguishable arms. The fact that there is a lot of dust but not much gas shows that they are ancient, which would appear to validate this notion.
However, there is one fundamental flaw; lenticular galaxies are significantly brighter on average than spiral galaxies. You'd expect them to be dimmer, not brighter, if they were actually fading spiral galaxies.
Some astronomers now propose that lenticular galaxies are the product of mergers between two ancient spiral galaxies as an alternative. This would account for the disc structure as well as the absence of free gas. The enhanced surface brightness would also be accounted for by the combined mass of two galaxies.
These merged galaxies would be consistent if S0s were generated by the merging of other spirals, and it would also explain the rising frequency of globular clusters. A galaxy merger might produce lenticular galaxies, which would increase the total star mass and give the newly merged galaxy a disk-like, arm-less look.
Observing face-on disc galaxies or having a sample of spheroidal galaxies can explain higher axial ratios.
Features Of A Lenticular Galaxy
Lenticular galaxies are members of the galactic zoo that are poorly understood. They are comparable to both spiral and elliptical galaxies in certain aspects, but they are thought to represent a transitional galactic type.
Lenticular galaxies, for example, resemble a dying spiral galaxy. Some of their other properties, such as their composition, are more elliptical galaxy-like. As a result, it's possible that they're a separate galaxy type.
Lenticular galaxies are one of a kind in that they feature both a large bulge and a visible disk component. They have far larger bulge-to-disk ratios than conventional spirals and lack the late-type galaxies' traditional spiral arm structure, although they may feature a central bar. The axis ratio distribution of a lenticular galaxy sample reveals this bulge dominance.
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Joan AgieBachelor of Science specializing in Human Anatomy
With 3+ years of research and content writing experience across several niches, especially on education, technology, and business topics. Joan holds a Bachelor’s degree in Human Anatomy from the Federal University of Technology, Akure, Nigeria, and has worked as a researcher and writer for organizations across Nigeria, the US, the UK, and Germany. Joan enjoys meditation, watching movies, and learning new languages in her free time.
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