Related papers: The variable OVIII Warm Absorber in MCG-6-30-15
The variable warm absorber seen with {\em ASCA} in the X-ray spectrum of MCG$-$6-30-15 shows complex time behaviour in which the optical depth of OVIII anticorrelates with the flux whereas that of OVII is unchanging. The explanation in…
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 present a detailed re-analysis of the two {\it ASCA} Performance Verification observations of the nearby Seyfert 1 galaxy MCG-6-30-15. Confirming the results of Fabian et al. (1994), we find definite evidence for the {\sc O\,vii} and…
We report on soft X-ray observations of the Seyfert 1 galaxy MCG-6-30-15 with the Low and Medium Energy Concentrator Spectrometers on board BeppoSAX. The time averaged 0.1-4 keV spectrum shows evidence for a complex warm absorber. K-edges…
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…
We present detailed evidence for a warm absorber in the Seyfert 1 galaxy MCG--6-30-15 and dispute earlier claims for relativistic O line emission. The HETG spectra show numerous narrow, unresolved (FWHM < 200 km/s) absorption lines from a…
We present a multiwaveband spectroscopic study of the nearby Seyfert 1 galaxy MCG-6-30-15. New optical spectra from the Anglo-Australian Telescope are presented which clearly show the effects of dust extinction/reddening on both the…
We present analysis and results from the Reflection Grating Spectrometer during the 320 ks XMM observation of the Seyfert 1 galaxy MCG-6-30-15. The spectrum is marked by a sharp drop in flux at 0.7 keV which has been interpreted by…
The Seyfert 1 galaxy, NGC3516 has been the subject of many absorption line studies at both ultraviolet and X-ray wavelengths. In the UV, strong, broad, variable associated metal line absorption with velocity width $\sim 2000$ \kms\ is…
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…
There are several Seyfert galaxies for which there is a discrepancy between the small column of neutral hydrogen deduced from X-ray observations and the much greater column derived from the reddening of the optical/UV emission lines and…
The spectrum of the bright Seyfert I galaxy MCG-6-30-15 shows a broad Fe K-alpha emission line, generally interpreted to originate very close to the central black hole which must then have a high spin. The observed X-ray variability is…
We present the first analysis of the X-ray warm absorber and nuclear obscuration in the Seyfert 1.8 galaxy ESO 113-G010. We used archival data from a 100 ks XMM-Newton observation made in 2005. From high resolution spectroscopy analysis of…
We present a detailed study of the ionised environment of the Seyfert 1 galaxy Mrk 704 using medium and high resolution X-ray spectra obtained with a long XMM-Newton observation. The 0.3-10 kev continuum, well described by a power-law…
A recent observation of the nearby (z=0.042) narrow-line Seyfert 1 galaxy RE J1034+396 on 2007 May 31 showed strong quasi-periodic oscillations (QPOs) in the 0.3-10 keV X-ray flux. We present phase-resolved spectroscopy of this observation,…
Many of the baryons associated with a galaxy reside in its circumgalactic medium (CGM), in a diffuse volume-filling phase at roughly the virial temperature. Much of the oxygen produced over cosmic time by the galaxy's stars also ends up…
Hubble Space Telescope images of MCG-6-30-15 show a dust lane crossing the galaxy just below the nucleus. In this paper, we argue that this dust lane is responsible for the observed reddening of the nuclear emission and the Fe I edge hinted…
We present the results from a 500 ks Chandra observation of the Seyfert 1 galaxy NGC 5548. We detect broadened emission lines of O VII and C VI in the spectra, similar to those observed in the optical and UV bands. The source was…
The Chandra HETGS spectra of the Seyfert 1 galaxy MCG--6-30-15 show numerous narrow, unresolved (FWHM < 200 km/s) absorption lines from a wide range of ionization states of N, O, Mg, Ne, Si, S, Ar, and Fe. The initial analysis of these…
X-ray absorption lines of highly-ionized species such as OVII at about zero redshift have been firmly detected in the spectra of several active galactic nuclei. However, the location of the absorbing gas remains a subject of debate. To…