A Search for Late-time Radio Emission and Fast Radio Bursts from Superluminous Supernovae

Abstract

We present results of a search for late-time radio emission and Fast Radio Bursts (FRBs) from a sample of type-I superluminous supernovae (SLSNe-I). We used the Karl G. Jansky Very Large Array to observe ten SLSN-I more than 5 years old at a frequency of 3 GHz. We searched fast-sampled visibilities for FRBs and used the same data to perform a deep imaging search for late-time radio emission expected in models of magnetar-powered supernovae. No FRBs were found. One SLSN-I, PTF10hgi, is detected in deep imaging, corresponding to a luminosity of 1.2 × 10 28 erg s −1 . This luminosity, considered with the recent 6 GHz detection of PTF10hgi in Eftekhari et al. (2019), supports the interpretation that it is powered by a young, fast-spinning (∼ ms spin period) magnetar with ∼ 15 M of partially ionized ejecta. Broadly, our observations are most consistent with SLSNe-I being powered by neutron stars with fast spin periods, although most require more free-free absorption than is inferred for PTF10hgi. We predict that radio observations at higher frequencies or in the near future will detect these systems and begin constraining properties of the young pulsars and their birth environments.

A Mildly Relativistic Outflow from the Energetic, Fast-rising Blue Optical Transient CSS161010 in a Dwarf Galaxy

“…The dwarf nature of the host galaxies of luminous FBOTs that are engine-driven (red stars in Figure 6) is reminiscent of that of some SLSNe and GRBs, which show a preference for low-mass galaxies (e.g., Lunnan et al 2014;Chen et al 2017;Schulze et al 2018), as independently pointed out by Ho et al (2020). A second clear similarity between luminous FBOTs, relativistic SNe and GRBs is the presence of relativistic outflows (Figure 5) and the associated luminous radio emission (Figure 1), which is clearly not present with similar luminosities in SLSNe (Coppejans et al 2018;Eftekhari et al 2019;Law et al 2019). 44 Yet, luminous FBOTs differ from any known class of stellar explosions with relativistic ejecta in two key aspects: (i) the temporal evolution and spectroscopic properties of their thermal UV/optical emission; (ii) CSS161010 showed evidence for a large mass coupled to its fastest (relativistic) outflow.…”

The physical mechanisms of fast radio bursts

“…It has been hypothesized that extreme cosmic explosions such as long GRBs, superluminous supernovae, and even short GRBs due to NS-NS mergers may give birth to extremely rapidly rotating magnetars 132 . Galactic magnetars likely did not go through these extreme channels, since their birth rate is much higher than the birth rate of those explosions 133 and since the supernova remnants of some Galactic Searches for FRBs in GRB or superluminous supernova remnants have been carried out and so far fruitless 72,73 (but see ref. 74 ).…”

“…Neither have searches for young-magnetar-powered FRBs 71 from the remnants of long GRBs or superluminous supernovae 72,73 (but see Ref. 74 ).…”

Three-dimensional Hydrodynamic Simulations of Supernova Ejecta with a Central Energy Source

“…Follow-up radio and X-ray observations of SLSNe-I from several 10 days to a few years after the discovery have been attempted, however, resulting in no undoubtful detection so far (Levan et al 2013;Coppejans et al 2018;Margutti et al 2018;Renault-Tinacci et al 2018;Bhirombhakdi et al 2018). Very recently, a bright radio source was identified in association with an almost 10years old SLSN, PTF10hgi (Law et al 2019), which may correspond to the theoretically predicted non-thermal radio emission from the embedded magnetized neutron star (e.g., Omand et al 2018).…”