Abstract:
LOFAR, the LOw-Frequency ARray, is a new-generation radio interferometer constructed in the north of the Netherlands and across
europe. Utilizing a novel phased-array design, LOFAR covers the largely unexplored low-frequency range from 10–240 MHz and
provides a number of unique observing capabilities. Spreading out from a core located near the village of Exloo in the northeast of the
Netherlands, a total of 40 LOFAR stations are nearing completion. A further five stations have been deployed throughout Germany,
and one station has been built in each of France, Sweden, and the UK. Digital beam-forming techniques make the LOFAR system
agile and allow for rapid repointing of the telescope as well as the potential for multiple simultaneous observations. With its dense
core array and long interferometric baselines, LOFAR achieves unparalleled sensitivity and angular resolution in the low-frequency
radio regime. The LOFAR facilities are jointly operated by the International LOFAR Telescope (ILT) foundation, as an observatory
open to the global astronomical community. LOFAR is one of the first radio observatories to feature automated processing pipelines
to deliver fully calibrated science products to its user community. LOFAR’s new capabilities, techniques and modus operandi make it
an important pathfinder for the Square Kilometre Array (SKA). We give an overview of the LOFAR instrument, its major hardware
and software components, and the core science objectives that have driven its design. In addition, we present a selection of new results
from the commissioning phase of this new radio observatory.
