Question

Explain the hydrogen atom's "galactic recycling" process, from molecular cloud to star to interstellar gas back to molecular cloud.

Answer 1

star-gas-star cycle summary

Atomic hydrogen clouds-->leads to molecular clouds--->then star formationce takes place --->stellar lives in this period and nuclear fusion happens for heavy element formation--->next gas returns in form of ,supernova and stellar winds--->hot bubbles forms --->Atomic hydrogen clouds again formed -->cycle repeats

Galactic recycling mainly involves two processes -recycling gases from old stars to form new stars and nuclear fusion happens for heavy element formation-

-All exhausted stars expels gases and new elements producing hot bubbles of gases and supernova explosion,Temperatures reaches 10^6 K with emission of X-rays

As the gas cools atomic hydrogen clouds form at around 100-10000K,emitting hydrogen line of 21 cm wavelength

As the cooling further takes place CO,H2 and other molecules form in the form of clouds.For CO emmision spectrum at 3 mm forms

New planets and stars are formed in the molecular clouds due to gravitational forces and cycle repeats