Mining the time axis with TRON. I. Millisecond pulsars in Omega Centauri, Terzan 5 and 47 Tucanae detected through MeerKAT interferometric imaging

Abstract

Medium-timescale (minutes to hours) radio transients are a relatively unexplored population. The wide field-of-view and high instantaneous sensitivity of instruments such as MeerKAT provides an opportunity to probe this class of sources, using image-plane detection techniques. We aim to systematically mine archival synthesis imaging data in order to search for medium-timescale transients and variables that are not detected by conventional long-track image synthesis techniques. We deploy a prototype blind transient and variable search pipeline named TRON. This processes calibrated visibility data, constructs high-time cadence images, performs a search for variability on multiple timescales, and extracts lightcurves for detected sources. As proof of concept, we apply it to three MeerKAT observations of globular clusters, known to host transient or variable sources. We detect a previously known eclipsing MSP suspected to be a `black widow' system, in the globular cluster Omega Centauri, with a light curve confirming the eclipsing nature of the emission. We detect a previously known `red back' eclipsing MSP in the globular cluster Terzan 5. Using observations of the globular cluster 47 Tucanae, we detect two known millisecond pulsars (MSPs), and one previously reported MSP candidate, with hints of eclipsing behaviour.

6 pages, 8 figures, published in MNRAS Letters

References in corpus (14)

• Eight new millisecond pulsars from the first MeerKAT globular cluster census
• Long-term observations of the pulsars in 47 Tucanae. I. A study of four elusive binary systems
• Low-frequency monitoring of flare star binary CR Draconis: Long-term electron-cyclotron maser emission
• MKT J170456.2-482100: the first transient discovered by MeerKAT
• Discovery of Millisecond Pulsars in the Globular Cluster Omega Centauri
• 21 new long-term variables in the GX 339-4 field: two years of MeerKAT monitoring
• Serendipitous discovery of radio flaring behaviour from a nearby M dwarf with MeerKAT
• MeerKAT discovery of 13 new pulsars in Omega Centauri
• Radio Variable and Transient Sources on Minute Timescales in the ASKAP Pilot Surveys
• Bursts from Space: MeerKAT - The first citizen science project dedicated to commensal radio transients
• A MeerKAT look at the polarization of 47 Tucanae pulsars: magnetic field implications
• Timing of Pulsars in the Globular Cluster Omega Centauri
• Commensal Transient Searches in Eight Short Gamma Ray Burst Fields
• Africanus IV. The Stimela2 framework: scalable and reproducible workflows, from local to cloud compute