EDP Sciences
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Volume 480, Number 1, March II 2008
Page(s) 69 - 77
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20078725

A&A 480, 69-77 (2008)
DOI: 10.1051/0004-6361:20078725

Slit and integral-field optical spectroscopy of the enigmatic quasar HE 0450-2958

G. Letawe1, P. Magain1, and F. Courbin2

1  Institut d'Astrophysique et Géophysique, Université de Liège, Allée du 6 Août, 17 Bâtiment B5C, 4000 Liège, Belgium
    e-mail: gletawe@ulg.ac.be
2  Laboratoire d'Astrophysique, École Polytechnique Fédérale de Lausanne (EPFL), Observatoire, 1290 Sauverny, Switzerland

(Received 24 September 2007 / Accepted 3 December 2007)

Context.Interest in the quasar HE 0450-2958 arose following the publication of the non-detection of its expected massive host, leading to various interpretations.
Aims.This article investigates the gaseous and stellar contents of the system through additional VLT/FORS slit spectra and integral field spectroscopy from VLT/VIMOS.
Methods.We apply our MCS deconvolution algorithm on slit spectra for the separation of the QSO and diffuse components, and develop a new method to remove the point sources in Integral Field Spectra, allowing extraction of velocity maps, narrow-line images, spatially resolved spectra or ionization diagrams of the surroundings of HE 0450-2958.
Results.The whole system is embedded in gas, mostly ionized by the QSO radiation field and shocks associated with radio jets. The observed gas and star dynamics are unrelated, revealing a strongly perturbed system. Despite longer spectroscopic observations, the host galaxy remains undetected.

Key words: galaxies: active -- quasars: individual: HE 0450-2958

© ESO 2008