Motive
Means
Opportunity
Opportunity
Trivial for field supernovae, as coincidence probability is 1e-6
star forming regions, however...
Energy = 1e51 erg
Sun's total radiative output
Most supernovae make neutron stars
Neutron stars are kicked
Ejecta dominated phase
transition when
Sedov Taylor Phase
transition to snowplough when radiation kicks in
Slow and steady wins the race
Supernova Remnant!
Molecular lines!
Molecular clouds are very dense, around 1e2/cc
Sedov Taylor age 1e4 years
Bonus: the cannonball passes through the centre
much smaller than molecular clouds!
Magnetar spin down age 1e4 years
SGR east is dusty - should have been destroyed in ST phase
How do supernovae evolve in such environments?
star cluster
wind
supernova explosion
600y
1500y
6000y
9000y
600y
1500y
6000y
9000y
600y
1500y
6000y
9000y
X - ray lobes - magnetar
age 1e4 years
SGR East only 1500 yo
Calls into question association with the cannonball
SGR East and the cannonball are not associated
SGR East - Cannonball association
X ray lobes - Magnetar association