  Considering general relativistic, two-dimensional (2D) supernova (SN)
explosion models of progenitor stars between 8.1 and 27 solar masses, we
systematically analyze the properties of the neutrino emission from core
collapse and bounce to the post-explosion phase. The models were computed with
the Vertex-CoCoNuT code, using three-flavor, energy-dependent neutrino
transport in the ray-by-ray-plus approximation. Our results confirm the close
similarity of the mean energies of electron antineutrinos and heavy-lepton
neutrinos and even their crossing during the accretion phase for stars with
M>10 M_sun as observed in previous 1D and 2D simulations with state-of-the-art
neutrino transport. We establish a roughly linear scaling of the electron
antineutrino mean energy with the proto-neutron star (PNS) mass, which holds in
time as well as for different progenitors. Convection inside the PNS affects
the neutrino emission on the 10-20% level, and accretion continuing beyond the
onset of the explosion prevents the abrupt drop of the neutrino luminosities
seen in artificially exploded 1D models. We demonstrate that a wavelet-based
time-frequency analysis of SN neutrino signals in IceCube will offer sensitive
diagnostics for the SN core dynamics up to at least ~10kpc distance. Strong,
narrow-band signal modulations indicate quasi-periodic shock sloshing motions
due to the standing accretion shock instability (SASI), and the frequency
evolution of such "SASI neutrino chirps" reveals shock expansion or
contraction. The onset of the explosion is accompanied by a shift of the
modulation frequency below 40-50Hz, and post-explosion, episodic accretion
downflows will be signaled by activity intervals stretching over an extended
frequency range in the wavelet spectrogram.
