相关论文: Coronal lines and the warm X-ray absorber in Seyfe…

We present results of the photoionization code IRIS, which calculates the spectrum emitted by the Warm Absorber (WA) in Seyfert 1 galaxies for a large grid of parameters (density, column density, ionization parameter...). We show that in…

Seyfert galaxies have been shown to exhibit a large variety of features in their X-ray spectra from which the environment of the central engine can be deduced. We focus on the two following aspects: the Warm Absorber, mainly responsible of…

The relation between the X-ray, the coronal line and the infrared (IR) emissions in a sample of the brightest known Seyfert galaxies is analysed. A close relationship between the absorption-corrected soft X-ray emission and both the mid-IR…

We discuss the optical coronal line spectra observed for a sample of 19 Narrow-Line Seyfert 1 galaxies. We find no correlation between the coronal line strength and the soft X-ray power-law index derived from ROSAT PSPC data. There is a…

We first provide a review of the properties of warm absorbers concentrating on what we have learned from ROSAT and ASCA. This includes dusty and dust-free warm absorbers, non-X-ray emission and absorption features of warm absorbers, and the…

We report the detection of ionized absorption in the ASCA spectrum of the narrow-line Seyfert 1 galaxy IRAS 17020+4544. Subsequent optical spectropolarimetry revealed high polarization increasing from 3% in the red to 5% in the blue,…

Recent {\it ASCA} observations confirm the presence of X-ray absorption due to partially ionized gas in many Seyfert 1 galaxies; the so-called warm absorber. Constraints on the location of the warm material are presented with the conclusion…

We study the variability of the warm absorber and the gas responsible for the emission lines in the Seyfert 1 galaxy NGC 5548, in order to constrain the location and physical properties of these components. Using X-ray spectra taken with…

We study the properties of warm absorbers in several active galaxies (AGN) and present new candidates, using ROSAT X-ray observations. Several aspects of the characteristics of warm absorbers are discussed, constraints on the density and…

X-ray spectroscopy of Seyfert 1 galaxies often reveal absorption edges resulting from photoionized gas along the line-of-sight to the central engine, the so-called warm absorber. I discuss how recent ASCA observations of warm absorber…

The launch of the Infrared Space Observatory and new atomic data have opened a window to the study of high ionization gas in active galactic nuclei (AGN). We present the results of a large number of photoionization simulations of the…

We present new images of the coronal line region, as traced by [Si VII] 2.48 \um, in some of the nearest Seyfert 2 galaxies. In each of these galaxies, the coronal line emission comprises a bright, compact central source and extended…

Signatures of warm absorbers are seen in soft X-ray spectra of about half of all Seyfert1 galaxies observed and in some quasars and blazars. We use the thermal equilibrium curve to study the influence of the shape of the ionizing continuum,…

We present He-like line ratios (resonance, intercombination and forbidden lines) for totally and partially photoionized media. For solar plasmas, these line ratios are already widely used for density and temperature diagnostics of coronal…

Warm absorbers are an important new tool for investigating the conditions within the central regions of active galaxies. They have been observed in ~50% of the well-studied Seyfert galaxies and have also been detected in quite a number of…

We report on the performance of the statistical, X-ray absorption lines identification procedure XLINE-ID. As illustration, it is used to estimate the time averaged gas density $n_H(r)$ of a representative AGN's warm absorber ($T\approx…

The relation between the X-ray emission, the infrared emission and the coronal line emission in a sample of the brightest known Seyfert galaxies is analyzed. A close relationship between the absorption-corrected soft X-ray emission and both…

The absorption lines in the soft X-ray spectrum of MCG--6-30-15 are studied using the Reflection Grating Spectrometer data from the 2001 XMM-Newton 320 ks observation. A line search of the full time-averaged spectrum reveals 51 absorption…

We have discovered a correlation between the X-ray absorbing column densities within Seyfert galaxies and the relative alignment between the central engines and their host galactic disks. This correlation carries several implications for…

High resolution X-ray spectroscopy of the warm absorber in the nearby X-ray bright Seyfert 1 galaxy, Mrk 1040 is presented. The observations were carried out in the 2013-2014 timeframe using the Chandra High Energy Transmission Grating with…