X-ray narrow line region variability as a geometry probe

Detmers, R. G.; Kaastra, J. S.; McHardy, I. M.

doi:10.1051/0004-6361/200911639

Cited by 21 publications

(42 citation statements)

References 27 publications

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“…However, Peterson et al (2013) measure a size for the [O III]-emitting region of 1−3 pc based on emission-line variability, consistent with the photoionization prediction of Kraemer et al (1998). Similarly, Detmers et al (2009) estimate a radius of 1−15 pc for the X-ray NLR.…”

Section: Agn Emission Featuressupporting

confidence: 61%

“…The rest wavelengths were all taken from the internal  line list. Table 6 also shows which of these narrow lines have been previously detected in NGC 5548 (Kaastra et al 2002;Steenbrugge et al 2005;Detmers et al 2009). …”

Section: Narrow Emission Line Parametersmentioning

confidence: 84%

“…Previous distance estimates for both the X-ray WA components (at least one component <7 pc; Detmers et al 2008) and X-ray NLR (1−15 pc; Detmers et al 2009) are similar, but the "obscurer" components discovered by Kaastra et al (2014) are known to be located much closer to the ionising source than the NLR. Therefore these "obscurer" components were not included in this absorption test.…”

Section: Absorptionmentioning

confidence: 86%

“…Variability has been presented by Detmers et al (2009), using O VII f (forbidden line) in the X-rays, and both Peterson et al (2013) and Denney et al (2014), using [O III] in the optical (the papers refer to NGC 5548 in the former two cases and Mrk 590 in the latter).…”

Section: Agn Emission Featuresmentioning

confidence: 99%

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Anatomy of the AGN in NGC 5548

Whewell

Branduardi‐Raymont

Kaastra

et al. 2015

A&A

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Context. Our consortium performed an extensive multi-wavelength campaign of the nearby Seyfert 1 galaxy NGC 5548 in 2013−14. The source appeared unusually heavily absorbed in the soft X-rays, and signatures of outflowing absorption were also present in the UV. He-like triplets of neon, oxygen and nitrogen, and radiative recombination continuum (RRC) features were found to dominate the soft X-ray spectrum due to the low continuum flux. Aims. Here we focus on characterising these narrow emission features using data obtained from the XMM-Newton RGS (770 ks stacked spectrum).Methods. We use  for our initial analysis of these features. Self-consistent photoionisation models from C are then compared with the data to characterise the physical conditions of the emitting region. Results. Outflow velocity discrepancies within the O VII triplet lines can be explained if the X-ray narrow-line region (NLR) in NGC 5548 is absorbed by at least one of the six warm absorber components found by previous analyses. The RRCs allow us to directly calculate a temperature of the emitting gas of a few eV (∼10 4 K), favouring photoionised conditions. We fit the data with a C model of log ξ = 1.45 ± 0.05 erg cm s −1 , log N H = 22.9 ± 0.4 cm −2 and log v turb = 2.25 ± 0.5 km s −1 for the emitting gas; this is the first time the X-ray NLR gas in this source has been modelled so comprehensively. This allows us to estimate the distance from the central source to the illuminated face of the emitting clouds as 13.9 ± 0.6 pc, consistent with previous work.

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Section: Agn Emission Featuressupporting

confidence: 61%

Section: Narrow Emission Line Parametersmentioning

confidence: 84%

Section: Absorptionmentioning

confidence: 86%

Section: Agn Emission Featuresmentioning

confidence: 99%

See 2 more Smart Citations

Anatomy of the AGN in NGC 5548

Whewell

Branduardi‐Raymont

Kaastra

et al. 2015

A&A

Self Cite

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“…This is both because of cross-calibration issues between the instruments and of differences in the analysis. In particular, as noticed also in U15, RGS and EPIC-pn are mismatched in flux in the overlapping band as a function of energy (e.g., Detmers et al 2009). On the other hand, NuSTAR spectra are systematically steeper than EPIC-pn spectra (∆Γ ∼ 0.1 see Cappi et al, in prep).…”

Section: The Short-term Variabilitymentioning

confidence: 59%

Anatomy of the AGN in NGC 5548

Gesu

Costantini

Ebrero

et al. 2015

A&A

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During an extensive multiwavelength campaign that we performed in 2013−2014, we found the prototypical Seyfert 1 galaxy NGC 5548 in an unusual condition of heavy and persistent obscuration. The newly discovered "obscurer" absorbs most of the soft X-ray continuum along our line of sight and lowers the ionizing luminosity received by the classical warm absorber. We present the analysis of the high resolution X-ray spectra collected with XMM-Newton and Chandra throughout the campaign, which are suitable to investigate the variability of both the obscurer and classical warm absorber. The time separation between these X-ray observations range from two days to eight months. On these timescales the obscurer is variable both in column density and in covering fraction. This is consistent with the picture of a patchy wind. The most significant variation occurred in September 2013 when the source brightened for two weeks. A higher and steeper intrinsic continuum and a lower obscurer covering fraction are both required to explain the spectral shape during the flare. We suggest that a geometrical change of the soft X-ray source behind the obscurer causes the observed drop in the covering fraction. Because of the higher soft X-ray continuum level, the September 2013 Chandra spectrum is the only X ray spectrum of the campaign in which individual features of the warm absorber could be detected. The spectrum shows absorption from Fe-UTA, O , and O , consistent with belonging to the lower-ionization counterpart of the historical NGC 5548 warm absorber.Hence, we confirm that the warm absorber has responded to the drop in the ionizing luminosity caused by the obscurer.

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Intermediate Line Region in AGNs

Adhikari

2019

Springer Theses

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X-ray narrow line region variability as a geometry probe

Cited by 21 publications

References 27 publications

Anatomy of the AGN in NGC 5548

Anatomy of the AGN in NGC 5548

Anatomy of the AGN in NGC 5548

Intermediate Line Region in AGNs

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