| Abstract : | FRBs are extremely bright, millisecond duration events detectable at cosmological distances. In addition to being probes of highly energetic, and possibly cataclysmic events, they also provide a unique opportunity to study the intergalactic medium (IGM). Their short duration and often non-repeating nature makes them both difficult to detect and localise. Localising them to arcsecond accuracy or greater helps identify their host galaxies, which allows their use as cosmological probes. While the detection rate of FRBs has grown remarkably, their localisation rate hasn’t. One possible solution is to use interferometers, which offer arcsecond to sub-arcsecond localisations. However, their narrow FoVs lead to poor detection rates. Thus, many interferometers have turned to commensal surveys (e.g., the VLA’s realfast survey or the ASKAP’s CRAFT), wherein objects of interest are searched for whenever the telescope is operational. Such surveys require a dedicated backend that analyses data in real time.
The SPOTLIGHT project with the GMRT, funded by the National Supercomputing Mission (NSM), is aiming to build a commensal backend to search for FRBs and pulsars using 2000 beams over a frequency range of 300 to 1460 MHz. In order to test the pipeline for this project end-to-end, we are building a real-time injection system for simulated FRBs. It will be able to inject FRBs into both beamformed intensity data and voltage time-series data. While the former has been demonstrated previously for both the UTMOST and the ASKAP, the latter has not. Injecting FRBs into antenna-based voltage time-series data will allow us to place them at particular sky positions, enabling the simultaneous testing of both the detection and localisation pipelines. In this presentation, we will describe these and other unique capabilities of our injection system. We will also highlight the detection and classification capabilities of a proof-of-concept multibeam setup at the GMRT. |
