An 80-kpc Lyman-alpha halo around a high redshift type-2 QSO
arXiv:0811.1776 · doi:10.1111/j.1365-2966.2008.14232.x
Abstract
We announce the discovery of an extended emission line region associated with a high redshift type-2 QSO. The halo, which was discovered in our new wide-field narrow-band survey, resides at z = 2.85 in the Spitzer First Look Survey region and is extended over ~80 kpc. Deep VLBI observations imply that approximately 50 per cent of the radio emission is extended on scales > 200pc. The inferred AGN luminosity is sufficient to ionize the extended halo, and the optical emission is consistent with being triggered coevally with the radio source. The Lyman-alpha halo is as luminous as those found around high redshift radio galaxies, however the active nucleus is several orders of magnitude less luminous at radio wavelengths than those FRIIs more commonly associated with extended emission line regions. AMS05 appears to be a high-redshift analogue to the radio-quiet quasar E1821+643 which is core dominated but which also exhibits extended FRI-like structure and contains an optically powerful AGN. We also find evidence for more quiescent kinematics in the Lyman-alpha emission line in the outer regions of the halo, reminiscent of the haloes around the more powerful FRIIs. The optical to mid-infrared SED is well described by a combination of an obscured QSO (L_bol ~3.4 +/- 0.2 x 10^13 Lsolar) and a 1.4 Gyr old simple stellar population with mass ~3.9 +/- 0.3 x 10^11 Msolar.
8 pages, 7 figures. Accepted by MNRAS
References in corpus (17)
- The synthesis of the cosmic X-ray background in the Chandra and XMM-Newton era
- Optical spectroscopy and X-ray detections of a sample of quasars and AGN selected in the mid-infrared from two Spitzer wide-area surveys
- Radio imaging of the Subaru/XMM-Newton Deep Field - I. The 100-microJy catalogue, optical identifications, and the nature of the faint radio source population
- A population of high-redshift type-2 quasars-I. Selection Criteria and Optical Spectra
- The Spitzer Space Telescope Extra-Galactic First Look Survey: 24 micron data reduction, catalog, and source identification
- Evidence for Cold Accretion onto a Massive Galaxy at High Redshift?
- Ly-alpha excess in high redshift radio galaxies: a signature of star formation
- Deep 610-MHz GMRT observations of the Spitzer extragalactic First Look Survey field - I. Observations, data analysis and source catalogue
- Evidence for a large fraction of Compton-thick quasars at high redshift
- Giant Lyman-alpha nebulae around z>2 radio galaxies: evidence for infall
- Infrared and millimetre-wavelength evidence for cold accretion within a z = 2.83 Lyman-alpha blob
- Mid-infrared spectroscopy of high-redshift obscured quasars
- Ionization of large-scale absorbing haloes and feedback events from high-redshift radio galaxies
- Giant Ly-alpha nebulae in the high redshift (z>2) Universe
- Fluorescent Lyman-alpha Emission from Gas Near a QSO at Redshift 4.28
- A population of high-redshift type-2 quasars-II. Radio Properties
- Deep u*- and g-band Imaging of the Spitzer Space Telescope First Look Survey Field : Observations and Source Catalogs