describe characteristics of a spiral galaxy

the ratio between the observed minor and major axial of a disk galaxy) distribution of a lenticular galaxy sample. This bulge dominance can be seen in the axis ratio (i.e. They have much higher bulge-to-disk ratios than typical spirals and do not have the canonical spiral arm structure of late-type galaxies, yet may exhibit a central bar. Lenticular galaxies are unique in that they have a visible disk component as well as a prominent bulge component. The inset is a visual representation of the profile of either at the specified minor (b) to major (a) axis ratios. The percentage of galaxies with a particular axis ratio (minor/major) for a sample of lenticular and spiral galaxies. The horizontal axis shows the morphological type, primarily dictated by the nature of the spiral arms. Grid showing the location of early-type galaxies (including the lenticular S0 galaxies) relative to the late-type spiral galaxies. This galaxy is a member of the Fornax Cluster.

Credit: HST NGC 1387 has a large nuclear ring. While this galaxy has been classified as an S0 galaxy, one can see the difficulty in differentiating among spirals, ellipticals, and lenticulars. Morphology and structure Classification NGC 2787 is an example of a lenticular galaxy with visible dust absorption. Connecting the E galaxies with the S0 galaxies are the ES galaxies with intermediate-scale discs. Both can be considered early-type galaxies that are passively evolving, at least in the local part of the Universe. Despite the morphological differences, lenticular and elliptical galaxies share common properties like spectral features and scaling relations. As a result, they consist mainly of aging stars (like elliptical galaxies). They may, however, retain significant dust in their disks. Lenticular galaxies are disc galaxies that have used up or lost most of their interstellar matter and therefore have very little ongoing star formation.

It contains a large-scale disc but does not have large-scale spiral arms. There is little to no gas and thus they are considered deficient in interstellar matter.Ī lenticular galaxy (denoted S0) is a type of galaxy intermediate between an elliptical (denoted E) and a spiral galaxy in galaxy morphological classification schemes. This image shows that lenticular galaxies may retain a considerable amount of dust in their disk. The Spindle Galaxy (NGC 5866), a lenticular galaxy in the constellation Draco.

Describe characteristics of a spiral galaxy