1999A&A...343L..40B

The STIS Hubble Deep Field South around the quasar J2233-606 was observed in the course of the VLT-UT1 Science Verification programme with the Test Camera in two broad-band filters, B and R, and in a narrow-band filter roughly centered at the quasar emission redshift, z_em=2.238. The most striking result is the discovery of a giant Lyα nebulosity around this radio-weak quasar, with an overall extent of 9.2"x12.1" or 121x159 h₅₀^–2kpc² and a luminosity of 3.1x10⁴⁴h₅₀^–2erg/s (for q₀=0), similar to those found around radio-loud quasars and radio galaxies. There are three additional emission-line candidates in a 1.11'x1.24' field with an observed Lyα flux above our 3σ Lyα detection limit of 1.9x10^–17erg/s/cm for point sources. The resolved bright object located 4.9'' north-east of the quasar, which has recently been identified as a galaxy at z_g=0.57, has an associated, weak Mg II absorption in the quasar spectrum.