# A Radio Source Coincident with the Superluminous Supernova PTF10hgi: Evidence for a Central Engine and an Analogue of the Repeating FRB121102?

## TL;DR

This paper reports the first detection of radio emission from a superluminous supernova, PTF10hgi, suggesting a central engine like a magnetar, and draws analogies with repeating FRB sources, with implications for understanding SLSN progenitors.

## Contribution

It presents the discovery of a coincident radio source with SLSN PTF10hgi and proposes a magnetar wind nebula or off-axis jet as its origin, indicating a central engine.

## Key findings

- Radio source coincident with PTF10hgi detected 7.5 years post-explosion.
- Radio properties are consistent with a magnetar wind nebula or off-axis jet.
- No FRBs detected from the source in follow-up observations.

## Abstract

We present the detection of an unresolved radio source coincident with the position of the Type I superluminous supernova (SLSN) PTF10hgi ($z=0.098$) about 7.5 years post-explosion, with a flux density of $F_\nu(6\,\,{\rm GHz)}\approx 47.3\ \mu Jy$ and a luminosity of $L_\nu(6\,\,{\rm GHz})\approx 1.1\times 10^{28}$ erg s$^{-1}$ Hz$^{-1}$. This represents the first detection of radio emission coincident with a SLSN on any timescale. We investigate various scenarios for the origin of the radio emission: star formation activity, an active galactic nucleus, and a non-relativistic supernova blastwave. While any of these would be quite novel if confirmed, none appear likely when taken in context of the other properties of the host galaxy, previous radio observations of SLSNe, and the general population of hydrogen-poor SNe. Instead, the radio emission is reminiscent of the quiescent radio source associated with the repeating FRB 121102, which has been argued to be powered by a magnetar born in a SLSN or LGRB explosion several decades ago. We show that the properties of the radio source are consistent with a magnetar wind nebula or an off-axis jet, indicating the presence of a central engine. Our directed search for FRBs from the location of PTF10hgi using 40 min of VLA phased-array data reveals no detections to a limit of $22$ mJy ($10\sigma$; 10 ms duration). We outline several follow-up observations that can conclusively establish the origin of the radio emission.