Random angular momentum in convection: delayed explosions of red supergiants following “failed” supernovae
Red supergiants (RSGs) are the most common stars that will undergo iron core collapse. Successful explosions of RSGs following core collapse lead to the most common supernovae, Type IIp. However, a fraction of core-collapse events may not lead to an immediate supernova explosion of the RSG. In those cases, a large fraction of the hydrogen envelope will fall in towards the newly-formed black hole. The angular momentum content of the infalling material determines whether accretion power can be liberated into driving an outflow or powering a luminous transient. I will show that, even in non-rotating RSGs, the random velocity field in the convective envelope carries significant angular momentum in each shell. Using 3D hydrodynamical simulations, I will show that infall of the convective envelope generates an energetic outflow. This drives nearly complete envelope ejection in an explosion with an energy of at least 10^48 ergs and with outflow speeds of hundreds of km/s./ The light curve of such an event would exhibit a characteristic, red plateau with a luminosity of at least ~few x 10^40 ergs and a duration of several hundreds of days. These events would appear quite similar to luminous red novae with red or yellow supergiant progenitors.
LOCATION:Phillips STATUS:CONFIRMED DTSTART:20230413T150000Z DTEND:20230413T160000Z END:VEVENT END:VCALENDAR