A double neutron star merger origin for the cosmological relativistic fading source PTF11agg?

TL;DR

This paper proposes that the transient PTF11agg could originate from a neutron star merger with a magnetar engine, providing a potential electromagnetic counterpart to gravitational wave events without gamma-ray signals.

Contribution

It introduces a model linking NS-NS mergers with magnetar engines to the observed transient, explaining PTF11agg without gamma-ray emission and highlighting its relevance for gravitational wave detection.

Findings

PTF11agg can be explained by a NS-NS merger with a magnetar engine.

Such mergers may produce electromagnetic signals detectable without gamma-ray triggers.

The model aligns with the properties of the observed transient and gravitational wave sources.

Abstract

The Palomar Transient Factory (PTF) team recently reported the discovery of a rapidly fading optical transient source, PTF11agg. A long-lived scintillating radio counterpart was identified, but the search for a high energy counterpart showed negative results. The PTF team speculated that PTF11agg may represent a new class of relativistic outbursts. Here we suggest that a neutron star (NS)-NS merger system with a supra-massive magnetar central engine could be a possible source to power such a transient, if our line of sight is not on the jet axis direction of the system. These systems are also top candidates for gravitational wave sources to be detected in the advanced LIGO/Virgo era. We find that the PTF11agg data could be explained well with such a model, suggesting that at least some gravitational wave bursts due to NS-NS mergers may be associated with such a bright electromagnetic counterpart without a \gamma-ray trigger.