4C +72.26

4C +72.26 known as NAME TX J1908+7220, is a radio galaxy located in the constellation Draco. At the redshift of 3.53, the galaxy is located roughly 11.5 billion light-years from Earth.

Characteristics
4C +72.26 is one of the high redshift powerful radio galaxies. An interacting pair of two vigorous starburst galaxies separated by ~1300 ± 200 km s−1 in velocity, 4C +72.26 is known to have tight locus following in the K-band Hubble diagram, suggesting it as a luminous (~3L*) galaxy with stellar populations forming rapidly at a very high redshift and such, evolved passively.

4C +72.26 is a massive galaxy lying inside the center of a galaxy cluster where galaxy formation is regulated and through growth by heating the intracluster medium. Energy that is released from the continued accretion of material, is then fueled towards its central supermassive black hole.

The molecular gas is known to end up between two colliding galaxies which displays absorption line profiles like P Cygni, while the active galactic nucleus host shows Lyα emission that indicative of a galaxy-wide "superwind". Moreover, the host is found to have a luminous highly ionized outflow. Despite showing a strong massive starburst, the ultraviolet-mid-infrared spectral energy distribution in 4C +72.26 is found to have a pre-existing stellar population that comprises ~1012 Msolar of stellar mass, with further ~2 per cent contributed by the current burst. This suggests that 4C +72.26 has assembled most of its final stellar mass.

4C +72.26 is classfied as a broad absorption-line radio galaxy with strong mid-infrared continua observed through spectrograph observations from Spitzer Telescope, according to research conducted by Dey in 1999, similar to those of broad absorption-line quasars with C IV trough extending bluewards to ~7000 km s−1.

With an upper spectrum appearing similar to the long-slit spectrum that is presented, the galaxy also have wavelength coverage up to ~8400 Å. Besides the narrow emission lines of Lyα and He II, several deep broad absorption troughs are seen, with sharper absorption features shortward of the predicted wavelengths that is O I1302 and C II1335 similar to 4C +41.17 and NGC 1741, a star-forming galaxy.