A radio galaxy at z=3.6 in a giant rotating Lyman $\alpha$ halo

Abstract

We present the discovery and detailed observations of the radio galaxy 1243+036 (=4C 03.24) at a redshift of $z=3.57$. The most spectacular feature of 1243+036 is the presence of a Ly$\alpha$ halo of luminosity $\sim 10^{44.5}$ ergs s${}^{-1}$ which extends over$\sim 20^{\prime \prime }$ (135 kpc). The narrow band imaging and the high resolution spectroscopy show that the Ly$\alpha$ gas has three distinct components: (i) gas with a high velocity dispersion (1550 km s${}^{-1}$ FWHM) located inside the radio structure, (ii) enhanced Ly$\alpha$ emission blue shifted by 1100 km s${}^{-1}$ at the location of the strong bend in the radio jet and (iii) Ly$\alpha$ emission extending out well beyond the radio lobes. This emission has a low velocity dispersion (250 km s${}^{-1}$ FWHM) and a velocity gradient of 450 km s${}^{-1}$ over the extent of the emission, indicative of large scale rotation. On the basis of these obserserations various mechanisms for the origin and kinematics of the Ly$\alpha$ halo are discussed.

accepted for publication in Astronomy and Astrophysics

Cited by in corpus (2)

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• The GLEAM 4-Jy (G4Jy) Sample: IV. Multiwavelength data and analysis