The binary companion of PSR J1740-3052

TL;DR

This paper identifies the near-infrared counterpart of the massive binary companion to pulsar PSR J1740-3052, confirming it as a main-sequence star and ruling out a black hole companion.

Contribution

The study provides the first identification of the binary companion to PSR J1740-3052 using near-infrared imaging and interferometric radio observations.

Findings

Counterpart has Ks=15.87+-0.10 and J-Ks>0.83.

The companion is consistent with a main-sequence star.

A stellar mass black hole is ruled out as the pulsar's companion.

Abstract

We report on the identification of a near-infrared counterpart to the massive (>11 Msun) binary companion of pulsar J1740-3052. An accurate celestial position of PSR J1740-3052 is determined from interferometric radio observations. Adaptive optics corrected near-infrared imaging observations show a counterpart at the interferometric position of the pulsar. The counterpart has Ks=15.87+-0.10 and J-Ks>0.83. Based on distance and absorption estimates from models of the Galactic electron and dust distributions these observed magnitudes are consistent with those of a main-sequence star as the binary companion. We argue that this counterpart is the binary companion to PSR J1740-3052 and thus rule out a stellar mass black hole as the pulsar companion.