26 - Supernova feedback

How long does it take for a massive star to run out of H to fuse into He?

Less than 30 Myr

As a massive star fuses heavier elements, it cools and swells into a __________.

Supergiant

As the supergiant implodes, it falls onto the remaining ___ ____, which causes a ____ ______, resulting in lighter material on the outside being flung out at tremendous speeds, upwards of 10000 m/s.

Ash core, core bounce

The shockwave heats surrounding gas to _______ of Kelvin, causing it to glow, brightening over days, visible for years, with the heavier material moving out more slowly, eventually turning into a _________ _______.

Millions, supernova remnant

As the hot material expands into cold interstellar gas, it forms into a ___________.

Superbubble

What is a superbubble?

A buoyant region of hot gas

How much energy does a supernova produce?

10^44 Joules

We expect SNII feedback to be in _____ ______ (happening early on, but not much today) and in ______ (very strong early on, still happening today).

Large spirals, dwarfs

What is the process of galaxies blowing out gas called?

Galactic winds

How do we observe galactic winds?

Look for unexpectedly high gas velocities around a galaxy

Supposing the hot wind entrains some cold gas alogn the way, the galaxy’s _____ will be absorbed by the cooler gas.

Light

Winds are seen ____ _____ at early times.

More often