10–13 Aug 2011
AlbaNova University Center
Europe/Stockholm timezone

Understanding Neutrino-Driven Supernova Explosions: the Antesonic Condition

10 Aug 2011, 17:45
5m
Oskar Klein (AlbaNova University Center)

Oskar Klein

AlbaNova University Center

Speaker

Mr Ondrej Pejcha (Department of Astronomy, Ohio State University)

Description

The mechanism of core-collapse supernovae is unknown. Despite considerable effort, most simulations of supernovae are not successful, and it has proven difficult to revive the stalled accretion shock, particularly for more massive stellar progenitors. Although it is known that the stalled accretion shock turns into explosion when the neutrino luminosity from the collapsed core exceeds a critical value (L_crit) (the "neutrino mechanism"), the physics of L_crit, as well as its dependence on the properties of the proto-neutron star (PNS) and changes to the heating/cooling mechanisms has never been systematically explored. We quantify the deep connection between the solution space of steady-state isothermal accretion flows with bounding shocks and the neutrino mechanism. In particular, we show that there is a maximum, critical sound speed above which it is impossible to maintain accretion with a standoff shock, because the shock jump conditions cannot be satisfied. The physics of this critical sound speed is general and does not depend on a specific heating mechanism. We show that if c_T^2/v_esc^2 >= 3/16 = 0.1875 explosion results - the "antesonic" condition. We generalize this result to the more complete supernova problem, where the critical condition for explosion can be written as c_S^2/v_esc^2 = 0.19 over a broad range in accretion rate and microphysics. Other criteria proposed in the supernova literature fail to capture the physics of L_crit. In addition, we explore effects of collective neutrino oscillations on L_crit.

Primary author

Mr Ondrej Pejcha (Department of Astronomy, Ohio State University)

Co-author

Prof. Todd Thompson (Department of Astronomy, Ohio State University)

Presentation materials

There are no materials yet.