galactic halo

American  

[guh-lak-tik hay-loh] / gəˈlæk tɪk ˈheɪ loʊ /

noun

1. Astronomy. a spheroidal region of stars, gas, and dark matter that surrounds a galaxy, such as the Milky Way, functioning as a stabilizing component of the galaxy.

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galactic halo British  

noun

1. astronomy a spheroidal aggregation of globular clusters, individual stars, dust, and gas that surrounds the Galaxy

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galactic halo Scientific  

1. A large, spherical region of relatively dust-free space surrounding a spiral galaxy such as the Milky Way. The inner regions of the galactic halo contain globular clusters of very old stars, while the outer regions are apparently occupied by large amounts of dark matter.

2. See also MACHO

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Example Sentences

Now, astronomers have begun to identify the remains of its meals smeared across the galactic halo, a huge spherical volume taking in the Milky Way’s spiral and much space beyond.

From Science Magazine • Feb. 16, 2022

Searle, L. & Zinn, R. Compositions of halo clusters and the formation of the galactic halo.

From Nature • Mar. 11, 2018

When a small galaxy is swallowed by the Milky Way, its member stars are stripped away and form streams of stars in the galactic halo.

From Textbooks • Oct. 13, 2016

Population II stars in the outer galactic halo and in globular clusters have much lower abundances of the heavy elements—often less than one-hundredth the concentrations found in the Sun and in rare cases even lower.

From Textbooks • Oct. 13, 2016

Instead, the velocity curve is almost flat, implying that there is a tremendous amount of matter in the galactic halo.

From Textbooks • Aug. 12, 2015