LOFAR - Opening up a new window on the Universe

TL;DR

LOFAR is a cutting-edge low-frequency radio telescope designed to explore fundamental astrophysical phenomena such as the epoch of reionisation, galaxy evolution, transient sources, and cosmic rays, offering significant advancements in sensitivity and resolution.

Contribution

This paper introduces LOFAR, a new radio telescope with enhanced capabilities for low-frequency observations, enabling novel studies of the early universe and high-energy astrophysical events.

Findings

LOFAR will enable detailed surveys of high-redshift radio galaxies.

It will improve understanding of diffuse emissions in distant galaxy clusters.

LOFAR's sensitivity will facilitate the detection of transient radio sources.

Abstract

LOFAR, the Low Frequency Array, is a next-generation radio telescope that is being built in Northern Europe and expected to be fully operational at the end of this decade. It will operate at frequencies from 15 to 240 MHz (corresponding to wavelengths of 20 to 1.2 m). Its superb sensitivity, high angular resolution, large field of view and flexible spectroscopic capabilities will represent a dramatic improvement over previous facilities at these wavelengths. As such, LOFAR will carry out a broad range of fundamental astrophysical studies. The design of LOFAR has been driven by four fundamental astrophysical applications: (i) The Epoch of Reionisation, (ii) Extragalactic Surveys and their exploitation to study the formation and evolution of clusters, galaxies and black holes, (iii) Transient Sources and their association with high energy objects such as gamma ray bursts, and (iv) Cosmic Ray showers and their exploitation to study the origin of ultra-high energy cosmic rays. In this conference the foreseen LOFAR work on the epoch of reionisation has been covered by de Bruyn and on cosmic ray showers by Falcke. During this contribution we will first present the LOFAR project with an emphasis on the challenges faced when carrying out sensitive imaging at low radio frequencies. Subsequently, we will discuss LOFAR's capabilities to survey the low-frequency radio sky. Main aims for the planned surveys are studies of z>6 radio galaxies, diffuse emission associated with distant clusters and starbursting galaxies at z>2.