ASTR-1010 Lecture Notes - Lecture 22: Supernova Remnant
27 Mar 2017
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Document Summary
Supernova remnant cools and begins to emit visible light as it expands. New elements made by supernova mix into interstellar medium. Multiple supernovae create huge hot bubbles that blow out of disk. Gas clouds cooling in the halo rain back down on disk. Composition: mostly h2, about 28% he, about 1% co, many other molecules (h2o, co, nh3, alcohol, etc. ) The matter in our galaxy emits different kinds of radiation, depending on what stage of the star-gas-star cycle it is in. Ionization nebulae: are found around short-lived high-mass stars, signifying active star formation. Reflection nebulae: scatter the light from stars: why do reflection nebulae look blue, for the same reason that our sky is blue! I(cid:374) the earth"s at(cid:373)osphere, there are dust particles that reflect and scatter the blue wavelengths of light from the sun better than they scatter the red wavelengths. Halo: no ionization nebulae, no blue stars no star formation.
