Are the infrared-faint radio sources pulsars?

TL;DR

This study investigates whether Infrared-Faint Radio Sources are pulsars by conducting radio observations, ultimately finding they are unlikely to be pulsars due to their lower flux densities.

Contribution

The paper provides the first targeted radio observations of IFRS to test the pulsar hypothesis, establishing that IFRS are not pulsars based on flux density limits.

Findings

IFRS are not radio pulsars based on flux density constraints.

Radio observations set upper limits below typical pulsar flux densities.

Supports alternative explanations for IFRS nature.

Abstract

Infrared-Faint Radio Sources (IFRS) are objects which are strong at radio wavelengths but undetected in sensitive Spitzer observations at infrared wavelengths. Their nature is uncertain and most have not yet been associated with any known astrophysical object. One possibility is that they are radio pulsars. To test this hypothesis we undertook observations of 16 of these sources with the Parkes Radio Telescope. Our results limit the radio emission to a pulsed flux density of less than 0.21 mJy (assuming a 50% duty cycle). This is well below the flux density of the IFRS. We therefore conclude that these IFRS are not radio pulsars.