spiral arms

spiral arms

(spÿ -răl) See density-wave theory; galaxies; Galaxy; self-propagating star formation.

spiral arms

[′spī·rəl ′ärmz]
(astronomy)
The shape of sections of certain galaxies called spirals; these sections are two so-called arms composed of stars, dust, and gas extending from the center of the galaxy and coiled about it.
References in periodicals archive ?
The disk consists of four spiral arms and has a diameter of about 120,000 light years.
"Multiple tightly wound spiral arms widen as they whirl outward from the galaxy's bright core, slowly fading and dissipating until these majestic structures disappear into the emptiness of intergalactic space, bringing a beautiful end to their starry splendor," the agency added.
The outer part of M77 is a broad, indistinct oval ring that's faintly connected to the much brighter central spiral arms. The central bar is surrounded by the spiral arms, and the AGN sits in the middle of it all.
Not to skip, the role of the careful optimization of the design parameters, such as the microstrip width (W), the number of turns, the spacing (S) between the spiral arms, height of the cavity, and height of the substrate and accurate modelling of the absorber, is also explained.
8, all the spiral arms are connected to a small junction with diameter d = 2[w.sub.m], and the n SMA connectors depicted in Fig.
Six of these "bones," each 40 to 150 light-years long and less than a light-year wide, appear to lie along nearby spiral arms of gas and stars that wind around the Milky Way.
WASHINGTON (CyHAN)- The arrangement of the spiral arms in the galaxy Messier 63, seen here in an image from the NASA/ESA Hubble Space Telescope, recall the pattern at the center of a sunflower.
If we could leave our galaxy and look down upon it, we would see a loose spiral shape, with a bright core and silvery spiral arms filled with stars and enormous clouds of gas.
The discovery, they said, helps explain how galactic spiral arms are formed.
Gradually, the fierce stellar winds from the youngest, most massive stars blow away the gas, revealing bright blue star clusters and giving a "Swiss cheese" appearance to the spiral arms. These youngest star clusters are about 1 million to 10 million years old.
What about M31's spiral arms? They can be seen, but perhaps not quite as you'd expect.
This antenna is composed by four spiral arms, each spiral arms length is Ml/4 (M is an integer).