Absorption line studies of galaxies along the line-of-sight to distant quasars allow a direct observational link between the properties of the extended gaseous disk/halo and of the star forming region of galaxies. In these proceedings we review recent work on Ca ii absorbers detected in the SDSS at 0.4 < z < 1.3 which, because of their dust content and chemical properties, may lie spatially clo...

With close pairs of quasars at different redshifts, a background quasar sightline can be used to study a foreground quasar’s environment in absorption. We used a sample of 17 Lyman limit systems with column density NHI > 10 19 cm selected from 149 projected quasar pair sightlines, to investigate the clustering pattern of optically thick absorbers around luminous quasars at z ∼ 2.5. Specifically...

We present results from a survey of weak Mg ii absorbers in the VLT/UVES spectra of 81 QSOs obtained from the ESO archive. In this survey, we identified 112 weak Mg ii systems within the redshift interval 0.4 < z < 2.4 with 86 % completeness down to a rest-frame equivalent width of Wr(2796) = 0.02 Å, covering a cumulative redshift path length of ∆Z ∼ 77.3. From this sample, we estimate that the...

Both ultraviolet (UV) and infrared (IR) light have negative impact on the human health. With this background it is main aim of current research to realize a textile material which able protect against both UV IR light. For research, regenerated cellulosic fibers from Lyocell process are used modified. Main analytical investigations done by photo-spectroscopy in arrangement diffuse transmission ...

Strong foreground absorption features from singly ionized magnesium (Mg II) are commonly observed in the spectra of quasars and are presumed to probe a wide range of galactic environments. To date, measurements of the average dark matter (DM) halo masses of intervening Mg II absorbers by way of large-scale cross-correlations with luminous galaxies have been limited to z < 0.7. In this work, we ...

Recent ultraviolet and X-ray observations of intergalactic OVI and OVII absorption systems along lines of sight to bright quasars have opened a new window onto the “warm-hot intergalactic medium” (WHIM). These systems appear to provide a significant reservoir for baryons in the local universe, and comparison to cosmological simulations suggests that their abundance roughly matches theoretical p...

We present a study of the Lyα forest at z . 0.4 from which we conclude that at least 20% of the total baryons in the universe are located in the highly-ionized gas traced by broad Lyα absorbers. The cool photoionized low-z intergalactic medium (IGM) probed by narrow Lyα absorbers contains about 30% of the baryons. We further find that the ratio of broad to narrow Lyα absorbers is higher at z . ...

Sb-substituted Cs2AgBiBr6 single crystals and powders are synthesized by various wet-chemical routes as well solvent-free mechanochemical synthesis. Phase purity resulting optical properties of differently absorbers investigated compared. X-ray diffraction confirms that Sb substitution results in an apparent single-phase formation with a unit cell shrinkage up to certain limit, which varies dep...

Nine quasar absorption spectra at 21-cm and ultraviolet (UV) rest-frame wavelengths are used to estimate possible variations in x ≡αgpμ, where α is the fine structure constant, gp the proton g-factor and μ ≡ me/mp is the electron-to-proton mass ratio. We find 〈 x/x〉 total = (0.63 ± 0.99) × 10−5 over a redshift range 0.23 zabs 2.35 which corresponds to look-back times of 2.7–10.5 billion years. ...

We study the physical origin of the low-redshift Lyα forest in hydrodynamic simulations of four cosmological models, all variants of the cold dark matter scenario. Our most important conclusions are insensitive to the cosmological model, but they depend on our assumption that the UV background declines at low redshift in concert with the declining population of quasar sources. We find that the ...