Speaker
Description
The LOw Frequency ARray (LOFAR) is one of the world's leading observatories at low radio frequencies. With its pan-European baselines reaching up to 2000 km in length, it is capable of achieving a sub-arcsecond angular resolution at frequencies below 200 MHz. However, the use of its international baselines has been hindered for most of the current lifetime of the observatory due to technical and logistical challenges: its phased-array design, the ionosphere and lacking software tools. For this reason, many projects, including the LOFAR Two-Metre Sky Survey (LoTSS), have relied only on the Dutch part of the array, using baselines up to 120 km. Thanks to the Long Baseline Working Group, a strategy has been developed to enable the calibration of the international stations. This has unlocked the highest resolutions (~0.3 arcseconds) attainable with LOFAR, enabling a wide variety of research for the first time. Equipped with the newly-developed LOFAR-VLBI pipeline, we have been working on following up LoTSS by post-processing the archival LoTSS data to obtain high-resolution (0.3") images of all reasonably bright sources within the Field of View of each pointing. Currently, we are finishing up Data Release 1 of LoTSS-HR, which is based on 30 LoTSS fields and will include the release of around 5000 high-resolution LOFAR images to the public. In this talk, I will give an overview of the LoTSS-HR project and its upcoming Data Release 1, including the details of the calibration strategy, the current results of the project and the future outlook.
