7 research outputs found
Proto-magnetar jets as central engines for broad-lined Type Ic supernovae
A subset of type Ic supernovae (SNe Ic), broad-lined SNe Ic (SNe Ic-bl), show
unusually high kinetic energies ( erg) which cannot be explained
by the energy supplied by neutrinos alone. Many SNe Ic-bl have been observed in
coincidence with long gamma-ray bursts (GRBs) which suggests a connection
between SNe and GRBs. A small fraction of core-collapse supernovae (CCSNe) form
a rapidly-rotating and strongly-magnetized protoneutron star (PNS), a
proto-magnetar. Jets from such magnetars can provide the high kinetic energies
observed in SNe Ic-bl and also provide the connection to GRBs. In this work we
use the jetted outflow produced in a 3D CCSN simulation from a consistently
formed proto-magnetar as the central engine for full-star explosion
simulations. We extract a range of central engine parameters and find that the
extracted engine energy is in the range of erg, the engine time-scale in the range of s and the
engine half-opening angle in the range of . Using these as
central engines, we perform 2D special-relativistic (SR) hydrodynamic (HD) and
radiation transfer simulations to calculate the corresponding light curves and
spectra. We find that these central engine parameters successfully produce SNe
Ic-bl which demonstrates that jets from proto-magnetars can be viable engines
for SNe Ic-bl. We also find that only the central engines with smaller opening
angles () form a GRB implying that GRB formation is likely
associated with narrower jet outflows and Ic-bl's without GRBs may be
associated with wider outflows.Comment: 13 pages, 12 figure
Giant Planet Formation and Migration
© 2018, The Author(s). Planets form in circumstellar discs around young stars. Starting with sub-micron sized dust particles, giant planet formation is all about growing 14 orders of magnitude in size. It has become increasingly clear over the past decades that during all stages of giant planet formation, the building blocks are extremely mobile and can change their semimajor axis by substantial amounts. In this chapter, we aim to give a basic overview of the physical processes thought to govern giant planet formation and migration, and to highlight possible links to water delivery.S.-J. Paardekooper is supported by a Royal Society University Research Fellowship. A. Johansen is supported by the Knut and Alice Wallenberg Foundation, the Swedish Research Council (grant 2014-5775) and the European Research Council (ERC Starting Grant 278675-PEBBLE2PLANET)