Absorption spectra of the QSO pair TOL 1037-27/1038-27

Observational signatures of feedback in QSO absorption spectra

Models for the formation of galaxies and clusters of galaxies require strong feedback in order to explain the observed properties of these systems. We investigate whether such feedback has observational consequences for the intergalactic medium, as probed in absorption towards background quasars. A typical quasar sight-line intersects one proto-cluster per unit redshift, and significant feedbac...

The absorption spectrum of the QSO PKS 2126 – 158 ( z em = 3 . 27 ) at high resolution ⋆

Spectra of the zem = 3.268 quasar PKS 2126– 158 have been obtained in the range λλ4300 − 6620 Å with a resolution R ≃ 27000 and an average signal-tonoise ratio s/n ≃ 25 per resolution element. The list of the identified absorption lines is given together with their fitted column densities and Doppler widths. The modal value of the Doppler parameter distribution for the Lyα lines is ≃ 25 km s. T...

Beyond the Pair Distribution Function in X-ray Absorption Spectra

A Near-solar Metallicity Damped Lyman-α System toward the Bal Quasar Tol 1037−2703

We report the detection of a Broad Absorption Line (BAL) outflow in the spectrum of the zem (Mg ii) = 2.201 QSO Tol 1037−2703 with three main BALs at 36000, 25300 and 22300 km s outflow velocities. Although the overall flow is dominated by high ionization lines like N v and C iv , the gas of highest velocity shows absorption from Mg i, Mg ii and Fe ii. Covering factor arguments suggest that the...

Spectral energy distribution of the metagalactic ionizing radiation field from QSO absorption spectra ⋆

A computational procedure is presented to estimate the spectral shape of the ionizing background between 1 and 10 Ryd by analyzing optically thin absorption systems in the spectra of high redshift quasars. The procedure is based on the response surface methodology from the theory of experimental design. The shape of the recovered UV background at z ∼ 3 shows a significant intensity decrease bet...