Serendipitous Discovery of Warm Absorbers in the Seyfert 2 Galaxy IRAS 18325-5926

Warm absorption is a common phenomenon in Seyfert 1s and quasars, but rare in Seyfert 2s. In this paper, we report the detection of warm absorbers with high energy resolution in the Seyfert 2 galaxy IRAS 18325-5926 for the first time with Chandra HETGS spectra. An intrinsic absorbing line system with an outflow velocity ~400 km/s was found, which is contributed by two warm absorbers with FWHM of 570 km/s and 1360 km/s, respectively. The two absorbers were adjacent, and doing a transverse motion across our line of sight. We constrained the distance of the absorbers to a small value, suggesting that the absorbers may originate from the highly ionized accretion disk wind. The perspective of this type 2 Seyfert provides the best situation to investigate the vertical part of the funnel-like outflows. Another weak absorbing line system with zero redshift was also detected, which could be due to Galactic absorption with very high temperature, or an intrinsic outflow with very high velocity ~6000 km/s.Comment: 14 pages, 10 figure

Joint fit of Warm Absorbers in COS and HETG spectra of NGC 3783

Warm Absorbers (WAs), as an important form of AGN outflows, show absorption in both the UV and X-ray bands. Using XSTAR generated photoionization models, for the first time we present a joint fit to the simultaneous observations of HST/COS and Chandra/HETG on NGC 3783. A total of five WAs explain well all absorption features from the AGN outflows, which are spread over a wide range of parameters: ionization parameter log xi from 0.6 to 3.8, column density log N-H from 19.5 to 22.3 cm(-2), velocity v from 380 to 1060 km s(-1), and covering factor from 0.33 to 0.75. Not all the five WAs are consistent in pressure. Two of them are likely different parts of the same absorbing gas, and two of the other WAs may be smaller discrete clouds that are blown out from the inner region of the torus at different periods. The five WAs suggest a total mass outflowing rate within the range of 0.22-4.1 solar mass per year

Granular Activated Carbon (GAC) Adsorption of Two Algal Odorants, Dimethyl Trisulfide and Β-Cyclocitral

This study was to investigate granular activated carbon (GAC) adsorption of two algal odorants in water, dimethyl trisulfide and β-cyclocitral. Among the four isotherm models (Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich), Freundlich isotherm showed the best fitting with the equilibrium data in terms of the coefficient of determination (R2) and Chi-square (x2). Based on the parameters determined in the Freundlich isotherm equations for GAC adsorption of a single odorant, we successfully predicted the GAC adsorption behavior in a bisolute solution using the Ideal Solution Adsorption (IAS) model. In the kinetics study of the two odorants adsorption by GAC, pseudo first-order and pseudo second-order kinetic models both well fit the experimental data. The calculated Gibbs free-energy changes for GAC adsorption of dimethyl trisulfide and β-cyclocitral were -3.61 and -4.24kJ/mol at 298K, respectively. The pH effects on GAC adsorption of dimethyl trisulfide and β-cyclocitral were different. Alkaline condition (pH \u3e10) favored GAC adsorption of dimethyl trisulfide, however, adsorption of the β-cyclocitral was not significantly influenced by pH (2-13). The presence of natural organic matter (NOM) hindered adsorption of dimethyl trisulfide and β-cyclocitral to different degrees. Low molecular weight NOM fractions (particularly \u3c1000) showed the significant inhibiting effect in the GAC adsorption