Is the soft excess in active galactic nuclei real

By Marek Gierlinski, C. Done. 2004

301 citations recorded by the source corpus.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/2c718f059640bfb5655fdb55960d0f83d72c4ede

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Citations in the corpus

X-ray variability of 104 active galactic nuclei - XMM-Newton power-spectrum density profiles (2012, background): “NLSy1 show strong soft excesses interpreted as optically thick material seen in reflection (Crummy et al., 2006) or optically thin material seen in absorption (Gierliński & Done, 2004).”
Suzaku observations of 'bare' active galactic nuclei (2012, background): “…it was suggested that the broad, overall curvature observed at low energies could still be caused by such absorption in an extremely turbulent outflow, in which large velocity broadening smears out the discrete atomic features (Gierliński & Done 2004; Middleton, Done & Gierliński 2007).”
Broad iron L line and X-ray reverberation in 1H0707-495 (2009, methodology): “This feature is common in other NLS1 (e.g Gierliński & Done 2004).”
The first ultraviolet quasar-stacked spectrum at z ≃ 2.4 from WFC3 (2015, methodology): “We have thus fixed the electron temperature kTe at 0.15 keV (Gierliński & Done 2004), fpl= 0.2, τ =18, and the default outer accretion disc radius, rout = 105Rg.”
BAT AGN Spectroscopic Survey. V. X-Ray Properties of the Swift/BAT 70-month AGN Catalog (2017, background): “…Vasudevan et al. 2014); ii) Comptonization of the seed optical/UV photons in plasma colder than that responsible for the primary X-ray component (e.g., Mehdipour et al. 2011; Done et al. 2012; Boissay et al. 2014, 2016); iii) smeared absorption by ionized material (e.g., Gierliński & Done 2004).”
Systematic effects in measurement of black hole masses by emission-line reverberation of active galactic nuclei: Eddington ratio and inclination (2006, background): “However the recent observations of very thick X-ray winds in some NLS1s (Pounds et al. 2003) and the suggestion by Gierlinski & Done (2004) and Chevallier et al. (2005) that the soft X-ray excess is due to the absorption by a very thick warm absorber, could perhaps rehabilitate this idea for high…”
X-ray spectral modelling of the AGN obscuring region in the CDFS: Bayesian model selection and catalogue (2014, background): “Processes that have been proposed to explain the soft component include thermal disk emission by the torus at kT ≈ 0.2 keV (Gierliński & Done 2004), or a relativistically blurred, photo-ionized reflection spectrum by the accretion disk (Ross & Fabian 1993).”
CAIXA: a catalogue of AGN in the XMM-Newton archive - II. Multiwavelength correlations (2009, background): “The “classical” interpretation of the soft excess as direct emission from the accretion disc was questioned when several studies (e.g. Gierliński & Done 2004; Crummy et al. 2006) showed that the observed temperature of the resulting black body is remarkably constant across orders of magnitude of…”
A Combined Optical and X-ray Study of Unobscured Type 1 AGN. I. Optical Spectra and SED Modeling (2011, background): “The origin of this so-called soft X-ray excess is still unclear (e.g. Gierliński & Done 2004; Crummy et al. 2006; Turner et al. 2007; Miller, Turner & Reeves 2008), and so some previous broadband SED modelling studies have explicitly excluded data below 1 keV.”
Radio-loud Narrow-Line Type 1 Quasars (2006, background): “1997, Wills et al. 2000, Bachev et al. 2004, Xu et al. 2003, 2006), metallicity (e.g. Mathur 2000, Komossa & Mathur 2001, Shemmer & Netzer 2002, Nagao et al. 2002, Warner et al. 2004, Fields et al. 2005), and absorption (e.g., Komossa & Meerschweinchen 2000, Gierlinski & Done 2004).”
Relativistic X-Ray Lines from the Inner Accretion Disks Around Black Holes (2007, background): “It is unlikely that the soft excess can be due to blurred absorption (e.g., Gierlinski & Done 2004), then, as encoding tangential velocities in absorption is extremely difficult, and a broad range of high velocities both toward and away from the observer along a single line of sight would be…”
X-RAY SPECTRAL PROPERTIES OF THE BAT AGN SAMPLE (2008, background): “We note that unlike the results of Gierliński & Done (2004), who found < kT >= 0.12 keV with σ = 0.02 keV for the PG quasars, we do see scatter in the values of kT (which becomes apparent in Figure 11).”
A physical model of the broad-band continuum of AGN and its implications for the UV/X relation and optical variability (2018, background): “These often show spectra at Lbol/LEdd ∼ 0.1–0.2 which are dominated by the thermal accretion disc emission, with only a small tail to higher energies from a hot Comptonisating corona (e.g., Kubota, Makishima, & Ebisawa 2001; Gierliński & Done 2004a; Steiner et al. 2009).”
On the origin of radio emission in radio-quiet quasars (2008, background): “…soft X-ray line emission (e.g. Sutherland & Dopita 1993), and it may be responsible for the ubiquitous soft excess emission feature seen below ∼0.7 keV, which is generally too strong to be explained by reprocessing of the harder X-ray continuum (e.g. Gierliński & Done 2004; Done & Nayakshin 2007).”
Intrinsic disc emission and the soft X‐ray excess in active galactic nuclei (2011, background): “In absorption, the line of sight velocity shear required to smearout the atomic features is probably unrealistically large (Gierliński & Done 2004; Schurch & Done 2007).”