Pulsar observations at millimetre wavelengths

TL;DR

This paper reviews the challenges and recent advancements in detecting pulsars at millimetre wavelengths, highlighting the potential for new discoveries with upcoming high-sensitivity facilities.

Contribution

It summarizes recent detections of pulsars at millimetre frequencies and discusses the prospects of future high-sensitivity observations with new observatories.

Findings

Detection of pulsars up to 291 GHz (1.03 mm)

Recent successful observations of pulsars and magnetars at millimetre wavelengths

Upcoming facilities will enable a new era of high-frequency pulsar astronomy

Abstract

Detecting and studying pulsars above a few GHz in the radio band is challenging due to the typical faintness of pulsar radio emission, their steep spectra, and the lack of observatories with sufficient sensitivity operating at high frequency ranges. Despite the difficulty, the observations of pulsars at high radio frequencies are valuable because they can help us to understand the radio emission process, complete a census of the Galactic pulsar population, and possibly discover the elusive population in the Galactic Centre, where low-frequency observations have problems due to the strong scattering. During the decades of the 1990s and 2000s, the availability of sensitive instrumentation allowed for the detection of a small sample of pulsars above 10$\,$GHz, and for the first time in the millimetre band. Recently, new attempts between 3 and 1$\,$mm ($\approx$86$-$300$\,$GHz) have resulted in the detections of a pulsar and a magnetar up to the highest radio frequencies to date, reaching 291$\,$GHz (1.03$\,$mm). The efforts continue, and the advent of new or upgraded millimetre facilities like the IRAM 30-m, NOEMA, the LMT, and ALMA, warrants a new era of high-sensitivity millimetre pulsar astronomy in the upcoming years.