Generalized compactness limit from an arbitrary viewing
Almog Yalinewich
Randoastro group meeting
21.3.19
Duration
~ 2 second
Length
x c
Isotropic Equivalent Energy
Energy density
Photon density
Optical depth to pair production
Before
After
Longer duration
Radius grows by
Optical depth diminishes by
Necessary Lorentz factor
Non relativistic optical depth
Single Messenger Era - On axis only
Off axis GRB
Compactness conditions for off axis emisison
Cosine theorem
Compare with radial delay
quality
quantity
Low and high energy pair production
Enough energy in a single photon
Most GRBs are edge on
More complicated spectrum allows for larger angles