The detection and X-ray view of the changing look AGN HE 1136-2304

Parker, M. L.; Komossa, S.; Kollatschny, W.; Walton, D. J.; Schartel, N.; Santos-Lleó, M.; Harrison, F.; Fabian, A. C.; Zetzl, M.; Grupe, D.; Rodríguez-Pascual, P. M.; Vasudevan, R. V.

doi:10.1093/mnras/stw1449

Cited by 59 publications

(62 citation statements)

References 82 publications

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“…It was noted that the [FeX]6374Å in some AGNs is broader than for other forbidden lines (Netzer 1974;Osterbrock & Shuder 1982). The variability of coronal lines has also been detected in a number of CL AGNs: NGC 4151, NGC 5548, NGC 7469, 3C 390.3 and others (Oknyanskij & Chuvaev 1982;Veilleux 1988;Oknyanskii et al 1991;Landt et al 2015a,b;Parker et al 2016). 5.…”

Section: Optical Spectrum: New Resultsmentioning

confidence: 88%

“…The Changing Look active galactic nuclei (CL AGNs) are objects which undergo dramatic variability of the emission line profiles and classification type, which can change from type 1 (showing both broad and narrow lines) to type 1.9 (where the broad lines almost disappear) or vice versa within a short time interval (typically a few months). The most extreme examples of known CL AGNs exhibit very strong changes not only in their broad Balmer lines, but also in their more narrow high-ionization lines like [FeVII], [FeX] and [FeXIV] (see e.g., Parker et al 2016). There are currently only a few dozen cases of CL AGNs recorded, but their number is growing steadily all the time, in particular during last 5 years (see e.g., )Shappee2014, Koay2016, MacLeod2016, Rinco2016, Rumbaugh2018, Yang2018.…”

Section: Introductionmentioning

confidence: 99%

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New changing look case in NGC 1566

Oknyansky

Winkler

Tsygankov

et al. 2018

Monthly Notices of the Royal Astronomical Society

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We present a study of optical, UV and X-ray light curves of the nearby changing look active galactic nucleus in the galaxy NGC 1566 obtained with the Neil Gehrels Swift Observatory and the MASTER Global Robotic Network over the period 2007 -2018. We also report on our optical spectroscopy at the South African Astronomical Observatory with the 1.9-m telescope on the night 2018 August 2-3. A substantial increase in X-ray flux by 1.5 orders of magnitude was observed following the brightening in the UV and optical bands during the last year. After a maximum was reached at the beginning of 2018 July the fluxes in all bands decreased with some fluctuations. The amplitude of the flux variability is strongest in the X-ray band and decreases with increasing wavelength. Low-resolution spectra reveal a dramatic strengthening of the broad emission as well as high-ionization [FeX]6374Å lines. These lines were not detected so strongly in the past published spectra. The change in the type of the optical spectrum was accompanied by a significant change in the X-ray spectrum. All these facts confirm NGC 1566 to be a changing look Seyfert galaxy.

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Section: Optical Spectrum: New Resultsmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

New changing look case in NGC 1566

Oknyansky

Winkler

Tsygankov

et al. 2018

Monthly Notices of the Royal Astronomical Society

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“…Right: a partial covering neutral absorber is added to the model and fitted to the OBS 1 data considering the whole energy range. as previously reported for other simultaneous observations (e.g., Parker et al 2016;Cappi et al 2016). In order to take into account the remaining calibration uncertainties, in the following we allowed to vary the photon index between the satellites.…”

Section: Emission Linesmentioning

confidence: 99%

XMM–Newton and NuSTAR joint observations of Mrk 915: a deep look into the X-ray properties★

Ballo

Severgnini

Ceca

et al. 2017

Monthly Notices of the Royal Astronomical Society

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We report on the X-ray monitoring programme (covering slightly more than 11 days) carried out jointly by XMM-Newton and NuSTAR on the intermediate Seyfert galaxy Mrk 915. The light curves extracted in different energy ranges show a variation in intensity but not a significant change in spectral shape. The X-ray spectra reveal the presence of a two-phase warm absorber: a fully covering mildly ionized structure [log ξ/(ergs cm s −1 ) ∼ 2.3, N H ∼ 1.3 × 10 21 cm −2 ] and a partial covering (∼ 90 per cent) lower ionized one [log ξ/(ergs cm s −1 ) ∼ 0.6, N H ∼ 2 × 10 22 cm −2 ]. A reflection component from distant matter is also present. Finally, a high-column density (N H ∼ 1.5 × 10 23 cm −2 ) distribution of neutral matter covering a small fraction of the central region is observed, almost constant, in all observations. Main driver of the variations observed between the datasets is a decrease in the intrinsic emission by a factor of ∼ 1.5. Slight variations in the partial covering ionized absorber are detected, while the data are consistent with no variation of the total covering absorber. The most likely interpretation of the present data locates this complex absorber closer to the central source than the narrow line region, possibly in the broad line region, in the innermost part of the torus, or in between. The neutral obscurer may either be part of this same stratified structure or associated with the walls of the torus, grazed (and partially intercepting) the line of sight.

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“…Only a few cases of the original definition of CL AGN are known, such as NGC 7603 (Tohline & Osterbrock 1976), NGC 7582 (Aretxaga et al 1999), NGC 2617 (Shappee et al 2014;Bon et al 2016), Mrk 590 (Denney et al 2014), HE 1135-2304 (Parker et al 2016), and SDSS J015957.64+003310.5 (LaMassa et al 2015;Merloni et al 2015). Significant spectral changes are found for instance in SDSS J1011+5442 (Runnoe et al 2016), J01264-0839 and J2336+00172 , and iPTF 16bco (Gezari et al 2017).…”

Section: Introductionmentioning

confidence: 99%

The Close AGN Reference Survey (CARS)

Krumpe

Tremblay

Urrutia

et al. 2017

A&A

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After changing optical AGN type from 1.9 to 1 in 1984, the AGN Mrk 1018 recently reverted back to its type 1.9 state. Our ongoing monitoring now reveals that the AGN has halted its dramatic dimming, reaching a minimum around October 2016. The minimum was followed by an outburst rising with ∼0.25 U-band mag/month. The rebrightening lasted at least until February 2017, as confirmed by joint Chandra and Hubble observations. Monitoring was resumed in July 2017 after the source emerged from sunblock, at which point the AGN was found only ∼0.4 mag brighter than its minimum. The intermittent outburst was accompanied by the appearance of a red wing asymmetry in broad-line shape, indicative of an inhomogeneous broad-line region. The current flickering brightness of Mrk 1018 following its rapid fading either suggests that the source has reignited, remains variable at a low level, or may continue dimming over the next few years. Distinguishing between these possibilities requires continuous multiwavelength monitoring.

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The detection and X-ray view of the changing look AGN HE 1136-2304

Cited by 59 publications

References 82 publications

New changing look case in NGC 1566

New changing look case in NGC 1566

XMM–Newton and NuSTAR joint observations of Mrk 915: a deep look into the X-ray properties★

The Close AGN Reference Survey (CARS)

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