EDP Sciences
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Volume 476, Number 3, December IV 2007
Page(s) 1205 - 1217
Section Extragalactic astronomy
DOI http://dx.doi.org/10.1051/0004-6361:20077342

A&A 476, 1205-1217 (2007)
DOI: 10.1051/0004-6361:20077342

Absorption spectrum of the quasar HS1603+3820

I. Observations and data analysis
A. Dobrzycki1, M. Nikolajuk2, J. Bechtold3, H. Ebeling4, B. Czerny5, and A. Rózanska5

1  ESO, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany
    e-mail: adam.dobrzycki@eso.org
2  Faculty of Physics, University of Bialystok, Lipowa 41, 15424 Bialystok, Poland
    e-mail: mrk@alpha.uwb.edu.pl
3  Steward Observatory, University of Arizona, Tucson, AZ 85721, USA
    e-mail: jbechtold@as.arizona.edu
4  Institute for Astronomy, University of Hawai'i, 2680 Woodlawn Drive, Honolulu, HI 96822, USA
    e-mail: ebeling@ifa.hawaii.edu
5  Copernicus Astronomical Center, Bartycka 18, 00716 Warszawa, Poland
    e-mail: bcz,agata@camk.edu.pl

(Received 22 February 2007 / Accepted 27 September 2007)

Context.We present multi-wavelength observations of the bright quasar HS1603+3820: the optical data taken with the MMT and Keck telescopes, with the 40-50 km s-1 resolution, and X-ray data taken by the Chandra X-ray Observatory satellite.
Aims.The optical spectra contain a very large number of absorption lines from numerous heavy elements. Our goal is to analyze these features to obtain constraints on the properties of associated absorbers, to be used in modeling of the quasar intrinsic flux and properties of the clouds.
Methods.We have determined the properties - column densities and redshifts - of the individual components. We derived the X-ray properties of HS1603+3820 and the optical-to-X-ray slope index $\alpha_{\rm ox}$.
Results.We found $\alpha_{\rm ox}$ of 1.70, which is at the high end of the typical range for a radio quiet quasar. We found 49 individual heavy element absorption clouds, which can be grouped into eleven distinct systems. Absorbers from the associated system, which likely is the one spatially closest to the quasar, show large $\ion{C}{iv}$ to $\ion{H}{i}$ column density ratio, reaching ~20.
Conclusions.Intrinsic X-ray properties of the quasar are typical. Determination of column densities of ions (including hydrogen) gives a strong foundation for modeling of the quasar ionising flux.

Key words: quasars: absorption lines -- quasars: individual: HS1603+3820

© ESO 2007