What are the boundaries of a galaxy?

Question

if there is a boundary to a galaxy, how would people define it? if not, then how is a galaxy considered a galaxy?

Answer 1

the distances between the cluster of billions of stars that form the milky way galaxy, and the stars that make up the nearest galaxy to us are vast voids of space, greater than the distance from our sun and solar system to the nearest star, thus the cluster can be distinguished as a unit.

and to correct the first answer, there is a dimension to our galaxy, and we can estimate the distances in terms of light years. this is well known fact, but obviously whoever wrote that answer is too ignorant to do any research before spewing his opinion as if it were fact.

Answer 2

A galaxy is a mass of billions of stars most likely revolving around a central black hole. To look at one galaxy "far, far away," there seems to be a clear edge to it.

But, if you define "boundary" as some PERFECT edge, you aren't going to really find it. The stars thin out at the edges of the galaxy. Maybe on a Hubble Telescope photograph you can see what looks like a edge of a plate shaped bunch of stars, but being that there exists innumerable objects out side of each galaxy, including dark matter which has yet to be fully explained, one could say the galaxy has NO boundaries, but just blends into other galaxies via all the space dust, dark matter, rogue planets, and all the other "stuff" out in space.

In fact, one scientist, who's name escapes me found that galaxies are in clusters with "strings" of matter connecting the clusters. This network makes up the universe. It's a difficult thing to comprehend.

Read, "Elegant Universe" by Brian Green. He's an astrophysicist and can explain things without all the really difficult vocabulary and math. Another author on such things is Michio Kaku. Maybe they can better answer your question.

Answer 3

Most galaxies don't have clearly defined boundaries. There are many different types of galaxies (spiral, elliptical, irregular, dwarf). Spirals are typically the largest and most massive ... with easily defined sections but each section merges gradually into each other... the galactic halo is the furtherest section of a galaxy and trying to pinpoint where it ends is virtually impossible to determine.

A galaxy is defined as: "A galaxy (from the Greek root galakt-, meaning "milk", a reference to our own Milky Way) is a massive, gravitationally bound system consisting of stars, an interstellar medium of gas and dust, and dark matter.[1][2] Typical galaxies range from dwarfs with as few as ten million[3] (107) stars up to giants with one trillion[4] (1012) stars, all orbiting a common center of mass. Galaxies can also contain many multiple star systems, star clusters, and various interstellar clouds." (from the wiki link below)

Answer 4

basically the boundy of a galaxy is the place where there is a low concentration of matter leading out into intergalactic space. if you think of a galaxy as being like a plate, the plate has edges, a galaxy is the same way, the last stars and gas at the edge is its boundry. i hope this helps!!!!!!

Answer 5

God's Kingdom

Answer 6

a limit hasnt been found but that shows how limited human science is

were just a race of ****** dumb asses who think the universe revolves around us


(please excuse my short rant)