Question

A giant cloud of slowly rotating material in a denser region starts to collapse gravitationally. The clumping of material in the disk and spiral arms triggers further waves of star formation. The central bulge has become a crowded place by this point, and a central supermassive black hole has formed or will do so shortly, and may go through an active galactic nucelus phase. Spiral galaxy During the last stages of the collapse, gas and dust from stars which have already died settle into a disk. Density waves start to form the spiral arms. Stars start to form in the outer parts of the giant collapsing cloud, the parts which will become the galactic halo. Some high mass stars go through their lifespans very rapidly, releasing the products of their nuclear fusion into the collapsing cloud, enriching it. Big Bang Some regions in the early Universe become denser than others (possibly due to underlying dark matter). As the cloud continues to collapse, gravitational potential energy turns into kinetic energy and material starts to collide. Angular momentum and collisions start to flatten the cloud into a disk. Star formation starts in the inward portions of the cloud.

Answer 1

A giant cloud of slowly rotating material in a denser region collapses gravitationally, leading to the formation of a spiral galaxy. Star formation occurs in the disk and spiral arms, as well as in the outer parts which become the galactic halo. This process is analogous to the formation of structures in the early Universe.

Step-by-step explanation:

A giant cloud of slowly rotating material in a denser region starts to collapse gravitationally. As the cloud continues to collapse, its gravitational potential energy turns into kinetic energy, causing material to start colliding. Angular momentum and collisions lead to the flattening of the cloud into a disk. Star formation then begins in the inward portions of the cloud.

The density waves formed by the clumping of material in the disk and spiral arms trigger further waves of star formation. This leads to the formation of spiral arms in a spiral galaxy. During the collapse, gas and dust from stars that have already died settle into a disk, and stars also start to form in the outer parts of the collapsing cloud, which will eventually become the galactic halo. Some high mass stars undergo rapid nuclear fusion, enriching the collapsing cloud with the products of fusion.

In the context of the formation of galaxies and stars, this process is analogous to the formation of structures in the early Universe. Some regions in the early Universe become denser than others, possibly due to underlying dark matter. These denser regions then collapse under their own gravitational pull, similar to the collapse of the giant cloud. This process eventually leads to the formation of galaxies and the onset of star formation.