2002/06/30 by A. J. Blustin, G. Branduardi‐Raymont, G. Branduardi-Raymont +8 · 2 citations
Physics and Astronomy · #Absorption (acoustics) #Absorption spectroscopy #Advanced X-ray Imaging Techniques #Argon #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Atomic physics #Emission spectrum #Galaxies: Formation, Evolution, Phenomena #Galaxy #Ion #Ionization #Line (geometry) #Neon #Optics #Physics #Plasma #Spectral line #Spectral resolution #Spectroscopy #Wavelength #astro-ph
paper · pdf · doi:10.1051/0004-6361:20020914
published as Astron.Astrophys. 392 (2002) 453 · 16 pages, 10 figures, accepted by Astronomy & Astrophysics; some measured wavelengths and blueshifts changed to correct a computing error
arxiv created 2002/07/19 · openalex publication_date 2002/08/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present the analysis of multi-wavelength XMM-Newton data from the Seyfert galaxy NGC 3783, including UV imaging, X-ray and UV lightcurves, the 0.2-10 keV X-ray continuum, the iron Kα emission line, and high-resolution spectroscopy and modelling of the soft X-ray warm absorber. The 0.2-10 keV spectral continuum can be well reproduced by a power-law at higher energies; we detect a prominent Fe Kα emission line, with both broad and narrow components, and a weaker emission line at 6.9 keV which is probably a combination of Fe Kβ and . We interpret the significant deficit of counts in the soft X-ray region as being due to absorption by ionised gas in the line of sight. This is demonstrated by the large number of narrow absorption lines in the RGS spectrum from iron, oxygen, nitrogen, carbon, neon, argon, magnesium, silicon and sulphur. The wide range of iron states present in the spectrum enables us to deduce the ionisation structure of the absorbing medium. We find that our spectrum contains evidence of absorption by at least two phases of gas: a hotter phase containing plasma with a log ionisation parameter ξ (where ξ is in erg cm s) of 2.4 and greater, and a cooler phase with log ξ centred around 0.3. The gas in both phases is outflowing at speeds of around 800 km s. The main spectral signature of the cold phase is the Unresolved Transition Array (UTA) of M-shell iron, which is the deepest yet observed; its depth requires either that the abundance of iron, in the cold phase, is several times that of oxygen, with respect to solar abundances, or that the absorption lines associated with this phase are highly saturated. The cold phase is associated with ionisation states that would also absorb in the UV.