We present results of full general relativistic (GR), three-dimensional (3D) core-collapse simulation of a massive star with multi-energy neutrino transport. Using a 70Mȯ zero-metallicity star, we show that the black-hole (BH) formation occurs at ∼ 300 ms after bounce. At a few ∼ 10 ms before the BH formation, we find that the stalled bounce shock is revived by neutrino heating from the forming hot proto-neutron star (PNS), which is aided by vigorous convection behind the shock. Our numerical results present the first evidence to validate the BH formation by the so-called fallback scenario. Furthermore we present results from a rapidly rotating core-collapse model of a 27Mȯ star that is trending towards an explosion. We point out that the correlated neutrino and gravitational-wave signatures, if detected, could provide a smoking-gun evidence of rapid rotation of the newly-born PNS.

Considering as many as 70% of massive stars interact with a binary companion (Sana et al.2012, 2014), we created a new model of the optical nebular emission of HII regions by combining the results of the Binary Population and Spectral Synthesis (BPASS, Eldridge, Stanway et al.2017) code with the photoionization code (CLOUDY). This is discussed more in detail in Xiao et al.2018a. Then we use this model to explore a variety of emission-line diagnostics of CCSN host HII regions from the PMAS/PPAK Integral-field Supernova hosts COmpilation (PISCO, Galbany et al.2018). We determine the age, metallicity and gas parameters for H II regions associated with CCSNe, contrasting the above variables to distribution type II and type Ibc SNe. We find their nebular emission and CCSN progenitor types are largely determined by past and ongoing binary interactions, for example mass loss, mass gain and stellar mergers. However we note these two types SNe have little preference in their host environment metallicity measured by oxygen abundance or in progenitor initial mass, except that at lower metallicities supernovae are more likely to be of type II. The BPASS and nebular emission models are available from bpass.auckland.ac.nz and warwick.ac.uk/bpass.

In this contribution, we present results from fully general-relativistic three-dimensional (3D) simulations of a non-rotating 15M⊙ star using different nuclear equations of state (EOSs). We show that the SASI (standing-accretion-shock-instability) activity occurs much more vigorously in models with softer EOS. By performing detailed analysis of the gravitational-wave (GW) emission, we find a new GW signature that is produced predominantly by the SASI-induced downflows to the proto-neutron star. We discuss the detectability of the GW signal by performing a coherent network analysis where multiple detectors including LIGO Hanford, LIGO Livingston, VIRGO, and KAGRA are considered. We point out that the GW signal, whose typical frequency is in the best sensitivity range of the laser-interferometers, could potentially provide the live broadcast that pictures how the supernova shock is dancing in the core. The detection horizon of the signal is estimated as 2~3 kpc for the current generation detectors, which can extend up to ~100 kpc for the third generation detectors like Cosmic Explorer. We furthermore perform a correlation analysis between the SASI-modulated GW and neutrino signals. Our results show that the time correlation of the two signals becomes highest when we take into account the travel timescale of adverting material from the (average) neutrino-sphere to the proto-neutron star surface.

In order to investigate the distinguishability about the progenitors of FeCCSNe and ECSNe, we calculate the luminosities and spectra of their pre-SN neutrinos and estimate the number of events at neutrino detectors.

We present early time (~0-50 days) bolometric light curves of UV-bright Core Collapse Supernovae observed with the Swift UV/Optical Telescope. We also generate pseudo-bolometric light curves from Swift UV and optical data and examine these by subtype as well as the observed and interpolated UV and IR flux contributions by epoch and bolometric corrections at early times from UV data.

We have performed three-dimensional (3D) hydrodynamical simulations of core-collapse supernovae (SNe) with multigroup neutrino transport to study non-axisymmetric effects in the context of neutrino heating explosion mechanism. By comparing one- (1D) and two dimensional (2D) results with those of 3D, we study how the increasing spatial multi-dimensionality affects the postbounce SN dynamics. The calculations were performed with an energy-dependent treatment of the neutrino transport that is solved by the isotropic diffusion source approximation scheme. In agreement with previous studies, our 1D model does not produce explosions for the 11.2 M⊙ star, while the neutrino-driven revival of the stalled bounce shock is obtained both in the 2D and 3D models. Our results show that convective matter motions below the gain radius become much more violent in 3D than 2D, making the neutrino luminosity larger for 3D. Enhanced by the large neutrino luminosity, the shock of the 3D model expands faster than that of the 2D. Our results show that the evolution of the shock is sensitive to the employed numerical resolutions. To draw a robust conclusion, 3D simulations with much higher numerical resolution and more advanced treatment of neutrino transport and gravity is needed.