We have used the Westerbork Synthesis Radio Telescope to detect HI 21cm absorption at z ∼ 0.7645 in the gravitational lens system towards PMN J0134−0931. The 21cm profile has two broad components, with peak optical depths of 0.047 ± 0.007 and 0.039 ± 0.007, at heliocentric redshifts 0.76470 ± 0.00006 and 0.76348 ± 0.00006, respectively. The redshift of the stronger component matches that of CaI...

We use the results of a set of three–dimensional SPH–Treecode simulations which model the formation and early evolution of disk galaxies, including the generation of heavy elements by star formation, to investigate the effects of dust absorption in quasar absorption line systems. Using a simple prescription for the production of dust, we have compared the column density, zinc abundance and opti...

We investigate through dedicated numerical simulations the evolution of the soft Xray absorption properties of a cloud surrounding a gamma-ray burst source. We show that the absorption properties of the material are strongly modified by the ionization induced by the intense burst flux. We derive the temporal evolution of the measured column density as a function of the density and size of the a...

In this work, CO2 capture by post-combustion using MEA is considered. The mechanistic model for the absorption process is elaborated and includes specie and energy balances for the liquid and gas phases. Model predictive control is implemented as a control strategy for the absorption column.

This paper presents a timing study and broadband spectral analysis of the broad-line radio galaxy 4C+74.26 based on a 35 ks XMM-Newton observation. As found in previous datasets, the source exhibits no evidence for rapid variability, and its 0.2–10 keV lightcurve is well fit by a constant. An excellent fit to the pn 0.3–12 keV spectrum was found using a continuum that combines an ionized and a ...

We have detected the J = 4 ← 3 rotational transition of CO in absorption at z = 0.89 towards the quasar PKS 1830−211, but not the CO (5 ← 4) or the P1 ← 3 P0 fine structure line of neutral carbon. The intervening molecular medium thus has a total CO column density of 10 cm ≤ N(CO) ≤ 5×10 cmwith a most likely value of N(CO) ≃ 2×10 cm, which corresponds to the large column density of molecular hy...

We report the detection of broad (FWHM 270kms 1) H I 21 cm absorption toward the compact (<15h 1 pc) radio nucleus of the nearby powerful radio galaxy Cygnus A. The absorption corresponds to a column density of hydrogen atoms of at least 2.54 0.44 1019 Tspin cm 2. Observations of OH and H2CO yielded upper limits. While other possibilities exist, we argue that the observed H I absorption plausib...

We have searched for redshifted absorption in the 21 cm line of neutral hydrogen toward 'red quasars', which are extragalactic radio sources with a steep spectral drop between optical and infrared wavelengths. The success rate for detecting HI 21cm absorption toward a representative sample of such sources is 80%. This compares to the much lower success rate of 11% for detecting HI 21cm absorpti...

We present the results of a long (∼ 93 ksec) XMM-Newton observation of the bright BL-Lac object PKS 0548-322 (z = 0.069). Our Reflection Grating Spectrometer (RGS) spectrum shows a single absorption feature at an observed wavelength λ = 23.33 ± 0.01 Å which we interpret as OVI Kα absorption at z = 0.058, i.e., ∼ 3000 kms from the background object. The observed equivalent width of the absorptio...