Lecture 17 - CHIME Flashcards
what is the purpose of CHIME? where can we get this info from another place?
designed to understand why the rate of universe expansion is increase
can also determine this from supernovae
what are the relative amounts of atoms, dark matter, and dark energy in the universe?
very small portion is atoms, a good chunk is dark matter, MOST IS DARK ENERGY
dark energy = ?
dark energy = accelerated expansion
describe CHIME letting us test Einstein’s theory of general relativity
it is a non-linear equation that is difficult to make predictions from –> maybe we need to modify it and look at dark energy?
what are fast radio bursts?
what do we know about how far they travel?
don’t actually know what they are but we see bright flashes of radio light that outshines the whole universe for ~1ms
radio is high wavelength and low energy so it travels slower –> so must be traveling large distance if they have delay in arrival time and are very bright
- probs from galaxies ~halfway across universe
why are fast radio bursts diff than other compact objects?
other compact objects have much dimmer light so they must be within our galaxies
what is the frequency of fast radio bursts?
GHz
how long do fast radio bursts last?
what does this mean?
0.001-3s
implies they are from compact objects bc compact objects release energy v quickly
describe fast radio bursts being highly dispersed
large time delay btwn long and short wavelength, telescope detects shortest wavelength first
describe the structure of CHIME
N-S beam with E-W light focused to hit the beam
describe what CHIME sees at a specific time, how can we view the whole sky?
at any time, only see 1 stripe of the sky BUT as earth rotates we will see the whole sky over the course of a day
CHIME vs normal telescope
CHIME:
1. can see any specific point as long as you wait for earth to rotate to that spot
2. pieces together parts of the sky so we can learn more –> not useful to observe something in location we already know about
normal telescope:
- mechanically point to specific point in sky you already know about
why is CHIME better at detecting FRB?
sees much larger area than other telescope, so increased chance of seeing flash –> detects 2000/day when the FRB falls on the stripe
have we seen FRBs more than 1x? how do we investigate this?
yes and we can further investigate by using the telescope to target one area
but we haven’t found patterns –> some in regions with old stars, new stars, no stars
