X-ray obscuration from a variable ionized absorber in PG 1114+445

Serafinelli, Roberto; Braito, V.; Severgnini, P.; Tombesi, Francesco; Giani, G. P.; Piconcelli, E.; Ceca, R. Della; Vagnetti, F.; Gaspari, M.; Saturni, Francesco Gabriele; Middei, R.; Tortosa, A.

doi:10.1051/0004-6361/202141474

Cited by 9 publications

(5 citation statements)

References 71 publications

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“…While there are more X-ray obscuration events in type 1 AGN in the literature (e.g., Rivers et al 2015;Gallo et al 2021;Serafinelli et al 2021; Armijos-Abendaño et al 2022), we limit our discussions on the physical properties of the obscurer in quasar MR 2251-178 in comparison with those observed with coordinated multiwavelength observations. They are one radioquiet quasar (PG 2112+059, Saez et al 2021) and six Seyfert galaxies: NGC 5548 (Kaastra et al 2014;Kriss et al 2019a), NGC 985 (Ebrero et al 2016), NGC 3783 (Mehdipour et al 2017Kaastra et al 2018a;Kriss et al 2019b), Mrk 335 (Longinotti et al 2013(Longinotti et al , 2019Parker et al 2019), Mrk 817 (Kara et al 2021;Miller et al 2021), and NGC 3227 (Mehdipour et al 2017;Mao et al 2022;Wang et al 2022).…”

Section: Discussionmentioning

confidence: 98%

Multiwavelength Observations of the Obscuring Wind in the Radio-quiet Quasar MR 2251-178

Mao

Kriss

Landt

et al. 2022

ApJ

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Obscuring winds driven away from active supermassive black holes are rarely seen due to their transient nature. They have been observed with multiwavelength observations in a few Seyfert 1 galaxies and one broad absorption line radio-quiet quasar so far. An X-ray obscuration event in MR 2251-178 was caught in late-2020, which triggered multiwavelength (near-IR (NIR) to X-ray) observations targeting this radio-quiet quasar. In the X-ray band, the obscurer leads to a flux drop in the soft X-ray band from late-2020 to early-2021. X-ray obscuration events might have a quasi-period of two decades considering earlier events in 1980 and 1996. In the UV band, a forest of weak blueshifted absorption features emerged in the blue wing of Lyα λ1216 in late-2020. Our XMM-Newton, NuSTAR, and Hubble Space Telescope/COS observations are obtained simultaneously; hence, the transient X-ray obscuration event is expected to account for the UV outflow, although they are not necessarily caused by the same part of the wind. Both blueshifted and redshifted absorption features were found for He i λ10830, but no previous NIR spectra are available for comparison. The X-ray observational features of MR 2251-178 shared similarities with some other type 1 active galactic nuclei (AGNs) with obscuring wind. However, observational features in the UV to NIR bands are distinctly different from those seen in other AGN with obscuring winds. A general understanding of the observational variety and the nature of obscuring wind is still lacking.

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Section: Discussionmentioning

confidence: 98%

Multiwavelength Observations of the Obscuring Wind in the Radio-quiet Quasar MR 2251-178

Mao

Kriss

Landt

et al. 2022

ApJ

View full text Add to dashboard Cite

show abstract

“…While there are more X-ray obscuration events in type 1 AGN in the literature (e.g., Rivers et al 2015;Gallo et al 2021;Serafinelli et al 2021;Armijos-Abendaño et al 2022), we limit our discussions on the physical properties of the obscurer in quasar MR 2251-178 in comparison with those observed with coordinated multi-wavelength observations. They are one radioquiet quasar (PG 2112+059, Saez et al 2021) and six Seyfert galaxies: NGC 5548 (Kaastra et al 2014;Kriss et al 2019b), NGC 985 (Ebrero et al 2016), NGC 3783 (Mehdipour et al 2017;Kaastra et al 2018b;Kriss et al 2019a), Mrk 335 (Longinotti et al 2013(Longinotti et al , 2019Parker et al 2019), Mrk 817 (Miller et al 2021;Kara et al 2021), and NGC 3227 (Mehdipour et al 2017;Wang et al 2022;Mao et al 2022).…”

Section: Discussionmentioning

confidence: 99%

Multi-wavelength observations of the obscuring wind in the radio-quiet quasar MR 2251-178

Mao¹,

Kriss²,

Landt³

et al. 2022

Preprint

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Obscuring winds driven away from active supermassive black holes are rarely seen due to their transient nature. They have been observed with multi-wavelength observations in a few Seyfert 1 galaxies and one broad absorption line radio-quiet quasar so far. An X-ray obscuration event in MR 2251-178 was caught in late 2020, which triggered multi-wavelength (NIR to X-ray) observations targeting this radio-quiet quasar. In the X-ray band, the obscurer leads to a flux drop in the soft X-ray band from late 2020 to early 2021. X-ray obscuration events might have a quasi-period of two decades considering earlier events in 1980 and 1996. In the UV band, a forest of weak blueshifted absorption features emerged in the blue wing of Lyα λ1216 in late 2020. Our XMM-Newton, NuSTAR, and HST/COS observations are obtained simultaneously, hence, the transient X-ray obscuration event is expected to account for the UV outflow, although they are not necessarily caused by the same part of the wind. Both blueshifted and redshifted absorption features were found for He i λ10830, but no previous NIR spectra are available for comparison. The X-ray observational features of MR 2251-178 shared similarities with some other type 1 AGNs with obscuring wind. However, observational features in the UV to NIR bands are distinctly different from those seen in other AGN with obscuring winds. A general understanding of the observational variety and the nature of obscuring wind is still lacking.

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“…For instance, the maximum distance from the black hole can be estimated by considering that the size of the absorbing clump R clump cannot be larger than the distance, i.e. R clump = N H /n < r max , where n is the density of the clump (e.g., Crenshaw & Kraemer 2012;Serafinelli et al 2021). From the ionization parameter definition the maximum distance from the black hole can be written as…”

Section: Ionized Absorbersmentioning

confidence: 99%

The NuSTAR view of the changing look AGN ESO 323-G77

Serafinelli¹,

Braito²,

Reeves³

et al. 2023

Preprint

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The presence of an obscuring torus at parsec-scale distances from the central black hole is the main ingredient for the Unified Model of Active Galactic Nuclei (AGN), as obscured sources are thought to be seen through this structure. However, the Unified Model fails to describe a class of sources that undergo dramatic spectral changes, transitioning from obscured to unobscured and vice-versa through time. The variability in such sources, so-called Changing Look AGN (CLAGN), is thought to be produced by a clumpy medium at much smaller distances than the conventional obscuring torus. ESO 323-G77 is a CLAGN that was observed in various states through the years with Chandra, Suzaku, Swift-XRT and XMM-Newton, from unobscured (N H < 3×10 22 cm −2 ) to Compton-thin (N H ∼ 1 − 6 × 10 23 cm −2 ) and even Compton-thick (N H > 1 × 10 24 cm −2 ), with timescales as short as one month. We present the analysis of the first NuSTAR monitoring of ESO 323-G77, consisting of 5 observations taken at different timescales (1, 2, 4 and 8 weeks from the first one) in 2016-2017, in which the AGN was caught in a persistent Compton-thin obscured state (N H ∼ 2 − 4 × 10 23 cm −2 ). We find that a Compton-thick reflector is present (N H,refl = 5 × 10 24 cm −2 ), most likely associated with the presence of the putative torus. Two ionized absorbers are unequivocally present, located within maximum radii of r max,1 = 1.5 pc and r max,2 = 0.01 pc. In one of the observations, the inner ionized absorber is blueshifted, indicating the presence of a possible faster (v out = 0.2c) ionized absorber, marginally detected at 3σ. Finally, we are able to constrain the coronal temperature and the optical depth of ESO 323-G77, obtaining kT e = 38 keV or kT e = 36 keV, and τ = 1.4 or τ = 2.8, depending on the coronal geometry assumed.

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X-ray obscuration from a variable ionized absorber in PG 1114+445

Cited by 9 publications

References 71 publications

Multiwavelength Observations of the Obscuring Wind in the Radio-quiet Quasar MR 2251-178

Multiwavelength Observations of the Obscuring Wind in the Radio-quiet Quasar MR 2251-178

Multi-wavelength observations of the obscuring wind in the radio-quiet quasar MR 2251-178

The NuSTAR view of the changing look AGN ESO 323-G77

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