TY - JOUR T1 - The ionization mechanism of the extended gas in high redshift radio galaxies: Shocks or AGN photoionization? JO - Astronomy and Astrophysics PY - 1997/01/01 AU - Villar-Martín M AU - Tadhunter C AU - Clark N ED - VL - 323 IS - 1 SP - 21 EP - 30 Y2 - 2024/12/23 ER -