Milky Way Dark Matter Halo
The visible disk of the Milky Way Galaxy is embedded in a much larger, roughly spherical halo of dark matter. The dark matter density drops off with distance from the galactic center. It is now believed that about 95% of the Galaxy is composed of dark matter, a type of matter that does not seem to interact with the rest of the Galaxy's matter and energy in any way except through gravity. The luminous matter makes up approximately 9 x 1010 solar masses. The dark matter halo is likely to include around 6 x 1011 to 3 x 1012 solar masses of dark matter.
Read more about this topic: Dark Matter Halo
Famous quotes containing the words milky way, milky, dark, matter and/or halo:
“Nothing has shown more fully the prodigious ignorance of human ideas and their littleness, than the discovery of [Sir William] Herschell, that what used to be called the Milky Way is a portion of perhaps an infinite multitude of worlds!”
—Horace Walpole (1717–1797)
“Go, smiling souls, your new-built cages break,
In heaven you’ll learn to sing, ere here to speak,
Nor let the milky fonts that bathe your thirst
Be your delay;
The place that calls you hence is, at the worst,
Milk all the way.”
—Richard Crashaw (1613?–1649)
“On Linden, when the sun was low,
All bloodless lay the untrodden snow,
And dark as winter was the flow
Of Iser, rolling rapidly.”
—Thomas Campbell (1774–1844)
“Older women can afford to agree that femininity is a charade, a matter of coloured hair, écru lace and whalebones, the kind of slap and tat that transvestites are in love with, and no more.”
—Germaine Greer (b. 1939)
“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)