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

Abstract

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.

Based on observations made with VLT/UT1 (program 76.B-0693(B)), and with the VLT/UT3 (program 72.B-0268(B)) at ESO-Paranal observatory in Chile, in addition with NASA/ESA Hubble Space Telescope observations from Cycle 13, proposal #10238.