Supernova and prompt gravitational-wave precursors to LIGO gravitational-wave sources and short-GRBs

TL;DR

This paper proposes that a small but significant fraction of LIGO gravitational-wave sources and short gamma-ray bursts could be preceded by supernova explosions occurring years to decades earlier, offering new insights into binary evolution.

Contribution

It introduces the idea that supernovae can serve as electromagnetic precursors to GW sources, supported by population-synthesis models predicting ultra-short delay times.

Findings

A fraction of GW sources may have supernova precursors.

Future GW detectors could observe pre-merger inspirals weeks to decades early.

Archival supernovae could be linked to GW events, revealing binary evolution details.

Abstract

Binary black-holes (BHs) and binary neutron-stars (NSs) mergers had been recently detected through gravitational-wave (GW) emission, with the latter followed by post-merger electromagnetic counterparts, appearing seconds up to weeks after the merger. While post-merger electromagnetic counterparts had been anticipated theoretically, very little electromagnetic precursors to GW-sources had been proposed, and non observed yet. Here we show that a fraction of ${\rm a}\,{\rm few\times}10^{-4}-10^{-1}$ of LIGO GW-sources and short-GRBs, could be preceded by supernovae-explosions years up to decades before the merger. Each of the BH/NS-progenitors in GW-sources are thought to form following a supernova, likely accompanied by a natal velocity-kick to the newly born compact object. The evolution and natal-kicks determine the orbits of surviving binaries, and hence the delay-time between the birth of the compact-binary and its final merger through GW-emission. We use data from binary evolution population-synthesis models to show that the delay-time distribution has a non-negligible tail of ultra-short delay-times between 1-100 yrs, thereby giving rise to potentially observable supernovae precursors to GW-sources. Moreover, future LISA/DECIGO GW space-detectors will enable the detection of GW-inspirals in the pre-mergers stage weeks to decades before the final merger. These ultra-short delay-time sources could therefore produce a unique type of promptly appearing LISA/DECIGO-GW-sources accompanied by \emph{coincident} supernovae. The archival (and/or direct) detection of precursor (coincident) SNe with GW and/or short-GRBs will provide unprecedented characterizations of the merging-binaries, and their prior evolution through supernovae and natal kicks, otherwise inaccessible through other means.