Non-relativistic radiation mediated shock breakouts. II. Bolometric properties of supernova shock breakout

Exact bolometric light curves of supernova shock breakouts are derived based on the universal, non-relativistic, planar breakout solutions, assuming spherical symmetry, constant Thomson scattering opacity, κ, and angular intensity corresponding to the steady-state planar limit. These approximations are accurate for progenitors with a scale height much smaller than the radius. The light curves are insensitive to the density profile and are determined by the progenitor radius R, and the breakout velocity and density, v ₀ and ρ₀, respectively, and κ. The total breakout energy, E _BO, and the maximal ejecta velocity, v _max, are shown to be E _BO = 8.0πR ²κ^-1 cv ₀ and v _max = 2.0v ₀, respectively, to an accuracy of about 10%. The calculated light curves are valid up to the time of transition to spherical expansion, t _sph R/4v ₀. Approximate analytic expressions for the light curves are provided for breakouts in which the shock crossing time at breakout, t ₀ = c/κρ₀ v ² ₀, is ≪R/c (valid for R < 10¹⁴ cm). Modifications of the flux angular intensity distribution and differences in shock arrival times to the surface, Δt _asym, due to moderately asymmetric explosions, affect the early light curve but do not affect v _max and E _BO. For 4v ₀ ≪ c, valid for large (red supergiant) progenitors, Lt ^-4/3 at max (Δt _asym, R/c) < t < t _sph and R may be accurately estimated from R 2 × 10¹³(L/10⁴³ erg s ^-1)^2/5(t/1 hr)^8/15.