Lecture 26 Flashcards
what elements can stars fuse to extract energy
up to iron
what happens as a supergiant implodes
it falls onto the remaining ash core causing a core bounce
lighter material on the outside is flung out
outer star material is swept into an explosion
what is the afterglow of a supergiant
the shockwave heats surrounding gas to extreme temps, brightens over days and is visible for years
heavier material moves out slowly
eventually supernovae remnant
what is a supernovae super bubble
hot material expanding into interstellar gas, it is buoyant
what are SNII responsible for element wise
almost solely responsible for oxygen and sodium
how much energy does each supernovae produce
10^44 J
how does the time to convert gas into stars scale
scales with the age of the universe
what do we expect SNII feedback to be
in large spirals, happening early on and not much today
in dwarfs, strong early on and still happening today
SNII feedback is stronger and longer lasting in smaller galaxies
what are galactic winds
galaxies blowing out gas
galactic winds now vs past
most galaxies today don’t show galactic winds, in the past we expect more and stronger winds
how do we detect galactic winds
look for unexpectedly high gas velocities around a galaxy
how can we detect galactic winds with absorption
hot wind picks up cold gas
galaxy light is absorbed by cooler gas
if blue shifted gas is moving towards us faster than anything within galaxy then there are outflows
how can we detect galactic winds with emission
outflowing gas emits photons
look for blue shifted wings attached to galaxies main emission
how can we detect galactic winds with high redshift
winds are saw at earlier times so more redshifted
