Antonia Rowlinson (CASS)

Antonia Rowlinson colloquium: Hunting for LOFAR transients with the TraP

Marsfield Lecture Theatre

Abstract

Title: Hunting for LOFAR transients with the TraP

Abstract: As a software-driven telescope, the Low Frequency Array (LOFAR) offers many different observing modes making it adaptable to requirements. The LOFAR Transients Key Science Project are utilising many of these capabilities to conduct a wide range of surveys in both beam formed and interferometric modes. Focusing on the image plane, we are searching for transient and variable sources on a range of timescales from years to seconds. In this talk, I will summarise the imaging capabilities of LOFAR, focusing on the Radio Sky Monitor (one of the dedicated transient surveys) and AARTFAAC (an all-sky radio transient monitor).

To search radio images for transients and variability in real-time, in a uniform and reliable manner, we have developed the LOFAR Transients Pipeline (TraP). There are a number of tuneable parameters that make TraP a versatile tool, adaptable to the needs of the astronomer and their datasets. However, it is not a trivial task to choose the optimal values of these parameters that will maximise the scientific output. I will present methods, based on machine learning techniques, that have been designed to choose appropriate image level quality control and transient search thresholds for given datasets. Once trained, these strategies can automatically reject poor quality images, reducing spurious sources and calibration instabilities, and reliably identify transient or variable source candidates.