The diversity of transients from magnetar birth in core collapse supernovae

• Published in: Monthly notices of the Royal Astronomical Society Vol. 454; no. 3; pp. 3311 - 3316
• Main Authors: Metzger, Brian D., Margalit, Ben, Kasen, Daniel, Quataert, Eliot
• Format: Journal Article
• Language: English
• Published: London Oxford University Press 11.12.2015
• Subjects: Astrophysics; Birth; Collapse; Gamma ray astronomy; Gamma ray bursts; Ionization; Magnetic fields; Neutron stars; Stars & galaxies; Supernovae; Symbols; gamma-ray burst: general; stars: magnetars; supernovae: general; pulsars: general
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stv2224

Strongly magnetized, rapidly rotating neutron stars are contenders for the central engines of both long gamma-ray bursts (LGRBs) and hydrogen-poor superluminous supernovae (SLSNe-I). Models for typical (minute long) LGRBs invoke magnetars with high dipole magnetic fields (B d ≳ 1015 G) and short spin-down times, SLSNe-I require neutron stars with weaker fields and longer spin-down times of weeks. Here, we identify a transition region in the space of B d and birth period for which a magnetar can power both a LGRB and a luminous supernova. In particular, a 2 ms period magnetar with a spin-down time of ∼104 s can explain both the ultralong GRB 111209 and its associated luminous SN2011kl. For magnetars with longer spin-down times, we predict even longer duration (∼105 − 6 s) GRBs and brighter supernovae, a correlation that extends to Swift J2058+05 (commonly interpreted as a tidal disruption event). We further show that previous estimates of the maximum rotational energy of a protomagnetar were too conservative and energies up to E max ∼ 1–2 × 1053 ergs are possible. A magnetar can therefore comfortably accommodate the extreme energy requirements recently posed by the most luminous supernova ASASSN-15lh. The luminous pulsar wind nebula powering ASASSN-15lh may lead to an ‘ionization breakout’ X-ray burst over the coming months, accompanied by a change in the optical spectrum.