Variability of Markarian 1018 - Seyfert 1.9 to Seyfert 1

Cohen, R. D.; Puetter, R. C.; Rudy, R. J.; Ake, T. B.; Foltz, C. B.

doi:10.1086/164758

Cited by 120 publications

(109 citation statements)

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“…Recent evidence of clumpy structures in the torus has been found from Spitzer/IRS spectra (Mor et al 2009). A clumpy moving absorber could also explain the optical change in the Seyfert type observed in some AGN (e.g., in Cohen et al 1986;Aretxaga et al 1999).…”

Section: Ugc 3142 and Eso 383-18mentioning

confidence: 94%

Multi-zone warm and cold clumpy absorbers in three Seyfert galaxies

Ricci

Beckmann

Audard

et al. 2010

A&A

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Aims. We present the first detailed X-ray analysis of three active galactic nuclei, the Seyfert 1 galaxies UGC 3142 and ESO 140-43, and the Seyfert 2 galaxy ESO 383-18, to study the geometry and the physical characteristics of their absorbers. Methods. High-quality XMM-Newton EPIC and RGS data were analyzed as well as Swift/XRT and BAT and INTEGRAL IBIS/ISGRI data to cover the 0.3−110 keV energy range. For ESO 140-43 also XMM-Newton/OM and Swift/UVOT data were used. We studied the variability of the three AGN on a time-scale of seconds using the EPIC/PN light curves, and the long-term time-scale variability of ESO 140-43 using two observations performed six months apart by XMM-Newton. Results. The spectra of the three Seyfert galaxies present a "soft excess" at energies E < 2 keV above a power law continuum that can be modeled by complex absorption, without any additional emission component. The X-ray sources in UGC 3142 and ESO 383-18 are absorbed by two layers of neutral material, with covering fractions f 1 0.92 and f 2 0.57 for UGC 3142, and f 1 0.97 and f 2 0.86 for ESO 383-18. While the clumpy absorber could be part of a disk wind or of the broad line region for UGC 3142, for ESO 383-18 a clumpy torus plus Compton thin dust lanes are more likely. The spectra of ESO 140-43 can be well fitted with a power law absorbed by three clumpy ionized absorbers with different covering factors, column densities, and ionization parameters, likely part of a moving clumpy system, which could be a disk wind or the broad line region. The strong spectral and flux variability on a time-scale of six months seen in ESO 140-43 is likely due to changes in the moving absorbers. We were able to detect the variation of the covering factor of one of the three ionized absorbers on a kilo-seconds time-scale in the EPIC light-curve of ESO 140-43.

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Section: Ugc 3142 and Eso 383-18mentioning

confidence: 94%

Multi-zone warm and cold clumpy absorbers in three Seyfert galaxies

Ricci

Beckmann

Audard

et al. 2010

A&A

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“…Cohen et al (1986) reported that Mrk 1018 changed from a Type 1.9 to Type 1 between 1979and 1984. More recently, McElroy et al (2016 discovered that Mrk 1018 returned to the Type 1.9 state, with the broad lines disappearing between 2009 and 2015.…”

Section: Introductionmentioning

confidence: 98%

Insight into “Changing-look” AGN Mrk 1018 from the Fe Kα Line: The Reprocessing Gas Has Yet to Fully Respond to the Fading of the AGN

LaMassa

Yaqoob

Kilgard

2017

ApJ

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Mrk 1018 is a "changing-look" AGN whose optical spectrum transitioned from a Type 1.9 to Type 1 between 1979 and 1984 and back to a Type 1.9 in 2015. This latest transition was accompanied by a decrease in X-ray flux. We analyze the Chandra spectra from 2010 and 2016 and NuSTAR spectra from 2016, carefully treating pile-up in the Chandra spectrum from 2010 and self-consistently modeling absorption, reflection, and Fe Kα line emission in the X-ray spectra from 2016. We demonstrate that while the 2-10 keV X-ray flux decreased by an order of magnitude (1. keV, due to a depressed AGN continuum. We jointly fit the Chandra and NuSTAR spectra from 2016 using the physically-motivated MYTorus model, finding that the torus orientation is consistent with a face-on geometry, and lines of sight intersecting the torus are ruled out. While we measure no line-of-sight absorption, we measure a column density of N H = 5.38 +14 −4.0 × 10 22 cm −2 for gas out of the line-of-sight which reprocesses the X-ray emission. We find a high relative normalization between the Compton scattered emission and transmitted continuum, indicative of time lags between the primary X-ray source and reprocessing gas. We predict that the Fe Kα line will respond to the decrease in AGN flux, which would manifest as a decrease in the Fe Kα EW.

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“…Risaliti et al 2009) and NGC 4051 (Guainazzi et al 1998), but these cloud events can be more common (Markowitz et al 2014). Prominent examples of AGN with appearing BLR are Mrk 1018 (Cohen et al 1986), NGC 1097(Storchi-Bergmann et al 1993, and NGC 2617 (Shappee et al 2014), and examples with disappearing BLR are NGC 7603 (Tohline & Osterbrock 1976), Mrk 590 (Denney et al 2014), SDSS J0159+0033 (LaMassa et al 2015, and SDSS J1011+5442 (Runnoe et al 2016). These events can either be explained by flares from tidal disruption events (TDEs) that are due to accretion of a star (e.g.…”

Section: Introductionmentioning

confidence: 99%

The Close AGN Reference Survey (CARS)

Husemann

Urrutia

Tremblay

et al. 2016

A&A

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We recently discovered that the active galactic nucleus (AGN) of Mrk 1018 has changed optical type again after 30 yr as a type 1 AGN. Here we combine Chandra, NuStar, Swift, Hubble Space Telescope and ground-based observations to explore the cause of this change. The 2-10 keV flux declines by a factor of ∼8 between 2010 and 2016. We show with our X-ray observation that this is not caused by varying neutral hydrogen absorption along the line-of-sight up to the Compton-thick level. The optical-UV spectral energy distributions are well fit with a standard geometrically thin optically thick accretion disc model that seems to obey the expected L ∼ T 4 relation. It confirms that a decline in accretion disc luminosity is the primary origin for the type change. We detect a new narrow-line absorber in Lyα blue-shifted by ∼700 km s −1 with respect to the systemic velocity of the galaxy. This new Lyα absorber could be evidence for the onset of an outflow or a companion black hole with associated gas that could be related to the accretion rate change. However, the low column density of the absorber means that it is not the direct cause for Mrk 1018's changing-look nature.

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Variability of Markarian 1018 - Seyfert 1.9 to Seyfert 1

Cited by 120 publications

References 0 publications

Multi-zone warm and cold clumpy absorbers in three Seyfert galaxies

Multi-zone warm and cold clumpy absorbers in three Seyfert galaxies

Insight into “Changing-look” AGN Mrk 1018 from the Fe Kα Line: The Reprocessing Gas Has Yet to Fully Respond to the Fading of the AGN

The Close AGN Reference Survey (CARS)

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