A dark matter halo is a hypothetical component of a galaxy that envelops the galactic disk and extends well beyond the edge of the visible galaxy. The halo's mass dominates the total mass. Since they consist of dark matter, halos cannot be observed directly, but their existence is inferred through their effects on the motions of stars and gas in galaxies. Dark matter halos play a key role in current models of galaxy formation and evolution.
Read more about Dark Matter Halo: Rotation Curves As Evidence of A Dark Matter Halo, Theories About The Nature of Dark Matter, Milky Way Dark Matter Halo
Famous quotes containing the words dark, matter and/or halo:
“For as she eats wisdom like the halves of a pear she puts one foot in front of the other. She climbs the dark wing.”
—Anne Sexton (1928–1974)
“If we take in our hand any volume; of divinity or school metaphysics, for instance; let us ask, Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning, concerning matter of fact and existence? No. Commit it then to flames: for it can contain nothing but sophistry and illusion.”
—David Hume (1711–1776)
“Most books belong to the house and street only, and in the fields their leaves feel very thin. They are bare and obvious, and have no halo nor haze about them. Nature lies far and fair behind them all. But this, as it proceeds from, so it addresses, what is deepest and most abiding in man. It belongs to the noontide of the day, the midsummer of the year, and after the snows have melted, and the waters evaporated in the spring, still its truth speaks freshly to our experience.”
—Henry David Thoreau (1817–1862)