EDP Sciences
Free access
Volume 406, Number 2, August I 2003
Page(s) 555 - 563
Section Galactic structure and dynamics
DOI http://dx.doi.org/10.1051/0004-6361:20030800

A&A 406, 555-563 (2003)
DOI: 10.1051/0004-6361:20030800

A hard medium survey with ASCA

IV. The radio-loud type 2 QSO AX J0843+2942
R. Della Ceca1, V. Braito1, 2, V. Beckmann3, A. Caccianiga1, I. Cagnoni4, I. M. Gioia5, T. Maccacaro1, P. Severgnini1 and A. Wolter1

1  Osservatorio Astronomico di Brera, via Brera 28, 20121 Milano, Italy
    e-mail: braito@brera.mi.astro.it; caccia@brera.mi.astro.it; tommaso@brera.mi.astro.it; paola@brera.mi.astro.it; anna@brera.mi.astro.it
2  Dipartimento di Astronomia, Università degli Studi di Padova, vicolo dell'Osservatorio 2, 35122 Padova, Italy
3  INTEGRAL Science Data Centre, Chemin d'Ecogia 16, 1290 Versoix, Switzerland
    e-mail: Volker.Beckmann@obs.unige.ch
4  Dipartimento di Scienze, Università dell'Insubria, Como, Italy
    e-mail: ilaria.cagnoni@uninsubria.it
5  Istituto di Radioastronomia CNR, via P Gobetti 101, 40129, Bologna, Italy
    e-mail: gioia@ira.cnr.it

(Received 27 February 2003/ Accepted 16 May 2003)

We discuss the X-ray, optical and radio properties of AX J0843+2942, a high luminosity Type 2 AGN found in the ASCA Hard Serendipitous Survey. The X-ray spectrum is best described by an absorbed power-law model with a photon index of  $\Gamma = 1.72^{+0.3}_{-0.6}$ and intrinsic absorbing column density of $N_{\rm H} = 1.44^{+0.33}_{-0.52} \times 10^{23}$ cm -2. The intrinsic luminosity in the 0.5-10 keV energy band is  $\simeq$ $3\times 10^{45}$ erg s -1, well within the range of quasar luminosities. AX J0843+2942, positionally coincident with the core of a triple and strong ( $S_{\rm 1.4~GHz} \sim 1$ Jy; $P_{\rm 1.4~GHz} \sim 9\times 10^{33}$ erg s -1 Hz -1) radio source, is spectroscopically identified with a Narrow Line object (intrinsic FWHM of all the permitted emission lines  $\la$ 1200 km s -1) at  z=0.398, having line features and ratios typical of Seyfert-2 like objects. The high X-ray luminosity, coupled with the high intrinsic absorption, the optical spectral properties and the radio power, allow us to propose AX J0843+2942 as a Radio-Loud "Type 2 QSO". A discussion of the SED of this object is presented here together with a comparison with the SED of Ultra Luminous Infrared Galaxies, other "Type 2 QSO" candidates from the literature, and "normal" Radio-Quiet and Radio-Loud QSOs.

Key words: galaxies: active -- quasars: individual: AX J0843+2942 -- X-rays: galaxies -- X-rays: individual: AX J0843+2942

Offprint request: R. Della Ceca, rdc@brera.mi.astro.it

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© ESO 2003