Black hole jets on the scale of the cosmic web.

When sustained for megayears (refs. ), high-power jets from supermassive black holes (SMBHs) become the largest galaxy-made structures in the Universe. By pumping electrons, atomic nuclei and magnetic fields into the intergalactic medium (IGM), these energetic flows affect the distribution of matter and magnetism in the cosmic web and could have a sweeping cosmological influence if they reached far at early epochs.

FR II radio galaxies at low frequencies - I. Morphology, magnetic field strength and energetics.

Due to their steep spectra, low-frequency observations of Fanaroff-Riley type II (FR II) radio galaxies potentially provide key insights in to the morphology, energetics and spectrum of these powerful radio sources. However, limitations imposed by the previous generation of radio interferometers at metre wavelengths have meant that this region of parameter space remains largely unexplored. In this paper, the first in a series examining FR IIs at low frequencies, we use LOFAR (LOw Frequency ARray) observations between 50 and 160 MHz, along with complementary archival radio and X-ray data, to explore the properties of two FR II sources, 3C 452 and 3C 223.

Jets, hotspots and lobes: what X-ray observations tell us about extra-galactic radio sources.

The brightest and most numerous discrete radio sources in the sky, radio galaxies and quasars, are powered by twin jets of plasma which emerge at relativistic speeds from very small regions at the centre of large elliptical galaxies, powered by mass infall on to supermassive black holes. The jets can carry material out to very large distances (millions of light years) where it forms balloon-like lobes. Until recently it has been impossible to make definite statements about the energy or the nature of the matter supplied by the jets, or the dynamics of the lobes as they expand into the external medium.