Do FRB Mark Dark Core Collapse?

TL;DR

This paper explores the possibility that some neutron stars form without supernovae, using FRB observations and models to suggest dark core collapses may occur, challenging traditional supernova theories.

Contribution

It proposes that dark neutron star formation without supernova remnants can be inferred from FRB dispersion measure stability and tests this hypothesis with observational constraints.

Findings

Unchanging dispersion measure in FRB 121102 suggests no supernova remnant.

Na"{1}ve supernova remnant models are statistically rejected based on observed data.

Dark core collapse formation may be a real astrophysical process, not just a model failure.

Abstract

Are some neutron stars produced without a supernova, without ejecting mass in a remnant? Theoretical calculations of core collapse in massive stars often predict this. The observation of the repeating FRB 121102, whose dispersion measure has not changed over several years, suggests that dark core collapses are not just failures of computer codes, but may be real. The existence of one repeating FRB with unchanging dispersion measure is not conclusive, but within a decade hundreds or thousands of FRB are expected to be discovered, likely including scores of repeaters, permitting useful statistical inferences. A na\"{\i}ve supernova remnant model predicts observable decline in dispersion measure for 100 years after its formation. If an upper limit on the decline of 2 pc/cm$^3$-y is set for five repeating FRB, then the na\"{\i}ve model with nominal parameters is rejected at the 95\% level of confidence. This may indicate dark neutron star formation without a supernova or supernova remnant. This hypothesis may also be tested with LSST data that would show, if present, a supernova at an interferometric FRB position if it occurred within the LSST epoch.