what is the rotation curve of a spiral galaxy
Galaxy rotation curve The rotation curve of a disc galaxy (also called a velocity curve) is a plot of the orbital speeds of visible stars or gas in that galaxy versus their radial distance from that galaxy's centre. It is typically rendered graphically as a plot, and the data observed from each side of a spiral galaxy are generally asymmetric, so that data from each side are averaged to create the curve. A significant discrepancy exists between the experimental curves observed, and a curve derived from theory. The theory of dark matter was postulated to account for the variance.[3]
Limit of a function (the Dirichlet function) has no limit at any x-coordinate.
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Backshore Sediments in this area are well-sorted and well-rounded. Its grain sizes are mainly coarse sand and medium sand, which are larger than that in littoral barrier dune.The sedimentary structures include parallel bedding and low-angle cross-bedding.