The soft X-ray/NLR connection: a single photoionized medium?

By S. Bianchi, M. Guainazzi, M. Chiaberge. 2005

187 citations recorded by the source corpus.

We present a sample of 8 nearby Seyfert 2 galaxies observed by HST and Chandra . All of the sources present soft X-ray emission which is coincident in extension and overall morphology with the [O iii] emission. The spectral analysis reveals that the soft X-ray emission of all the objects is likely to be dominated by a photoionized gas. This is strongly supported by the 190 ks combined XMM- Newton /RGS spectrum of Mrk 3, which different diagnostic tools confirm as being produced in a gas in photoionization equilibrium with an important contribution from resonant scattering. We tested with the code cloudy a simple scenario where the same gas photoionized by the nuclear continuum produces both the soft X-ray and the [O iii] emission. Solutions satisfying the observed ratio between the two components exist, and require the density to decrease with radius roughly like r -2 , similarly to what often found for the Narrow Line Region.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/7dee26499b17bf6ea3935883957e24121a23a588

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. D. M. Alexander
2. G. Hasinger
3. E. Treister
4. A. Comastri
5. Y. Ueda
6. P. Hopkins
7. W. N. Brandt
8. L. Hernquist

In Nuclear and High Energy Physics

1. G. Hasinger
2. A. Comastri
3. E. Treister
4. Y. Ueda
5. R. Gilli
6. R. Mushotzky
7. J. Tueller
8. F. E. Bauer

Citations in the corpus

• The Compact, Conical, Accretion-Disk Warm Absorber of the Seyfert 1 Galaxy NGC 4051 and Its Implications for IGM-Galaxy Feedback Processes (2007, background): “A constant ionization parameter with radius could be expected if the density decreases with the inverse square of the distance, as observed by Bianchi et al. (2006) for the kpc scale nebulae in type 2 objects.”
• BAT AGN Spectroscopic Survey. V. X-Ray Properties of the Swift/BAT 70-month AGN Catalog (2017, background): “…possibly related to star formation (e.g., Iwasawa et al. 2011); ii) radiative-recombination continuum created by gas photoionized by the AGN (e.g., Bianchi et al. 2006; Guainazzi & Bianchi 2007); iii) scattering of the primary X-ray emission in Compton-thin circumnuclear material (e.g., Ueda et…”
• The synthesis of the cosmic X-ray background in the Chandra and XMM-Newton era (2006, background): “…powerlaw by hot gas (Matt et al. 1996); iii) leakage of a fraction of the primary radiation through an absorbing medium which covers only partially the nuclear source (Vignali et al. 1998, Malaguti et al. 1999); iv) sum ofunresolved emission lines from photoionized gas (Bianchi et al. 2006a).”
• On the origin of soft X-rays in obscured AGN: answers from high-resolution spectroscopy with XMM–Newton (2006, background): “A solution in terms of AGN-photoionized gas can also c© 0000 RAS explain the coincidence in extension and overall morphology between soft X-ray emission and the Narrow Line Regions (NLRs), the latter traced by O[iii] HST maps, on scales as large as a few hundred parsecs (Bianchi et al. 2006).”
• Suzaku Observations of Active Galactic Nuclei Detected in the Swift BAT Survey: Discovery of a “New Type” of Buried Supermassive Black Holes (2007, background): “Such emission probably originates from the same extended gas responsible for the optical [O III] emission (Bianchi et al. 2006).”