Signs of gas flows in the variable Balmer line profiles 
 of the Seyfert galaxy nuclei NGC 3227 and NGC 7469

Pronik, I. I.

doi:10.1051/0004-6361/20079180

Cited by 4 publications

(3 citation statements)

References 15 publications

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“…Unfortunately the data are not of high quality, the source remains absorbed in the various models tested, and we cannot exclude at the present stage whether the absorption is simple or rather complex/ionized. Regarding the possibility that optical/X-ray mismatch is due to variability, we note that a few of the sources listed in Table 3 have changed their classification over time: NGC 4151 from type 1 to type 2 and back, Mrk 6 and NGC 3227 from type 2 to type 1 (Osterbrock & Koski 1976;Pronik 2009;Shapovalova et al 2009). However, these types of transitions have always been associated with continuum changes with the type 2 designation found when the optical ionizing flux was in a low state.…”

Section: Absorbed Type 1 Agnmentioning

confidence: 99%

TheINTEGRAL/IBIS AGN catalogue - I. X-ray absorption properties versus optical classification

Malizia

Bassani

Bazzano

et al. 2012

Monthly Notices of the Royal Astronomical Society

126

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In this work we present the most comprehensive INTEGRAL AGN sample. It lists 272 AGN for which we have secure optical identifications, precise optical spectroscopy and measured redshift values plus X-ray spectral information, i.e. 2-10 keV and 20-100 keV fluxes plus column density. Here we mainly use this sample to study the absorption properties of active galaxies, to probe new AGN classes and to test the AGN unification scheme. We find that half (48%) of the sample is absorbed while the fraction of Compton thick AGN is small (∼7%). In line with our previous analysis, we have however shown that when the bias towards heavily absorbed objects which are lost if weak and at large distance is removed, as it is possible in the local Universe, the above fractions increase to become 80% and 17%. We also find that absorption is a function of source luminosity, which implies some evolution in the obscuration properties of AGN. Few peculiar classes, so far poorly studied in the hard X-ray band, have been detected and studied for the first time such as 5 XBONG, 5 type 2 QSOs and 11 LINERs. In terms of optical classification, our sample contains 57% of type 1 and 43% of type 2 AGN; this subdivision is similar to that found in X-rays if unabsorbed versus absorbed objects are considered, suggesting that the match between optical and X-ray classification is overall good. Only a small percentage of sources (12%) does not fulfill the expectation of the unified theory as we find 22 type 1 AGN which are absorbed and 10 type 2 AGN which are unabsorbed. Studying in depth these outliers we found that most of the absorbed type 1 AGN have X-ray spectra characterized by either complex or warm/ionized absorption more likely due to ionized gas located in an accretion disk wind or in the biconical structure associated to the central nucleus, therefore unrelated to the toroidal structure. Among 10 type 2 AGN which resulted to be unabsorbed, at most 3-4% is still eligible to be classified as a "true" type 2 AGN.

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Section: Absorbed Type 1 Agnmentioning

confidence: 99%

TheINTEGRAL/IBIS AGN catalogue - I. X-ray absorption properties versus optical classification

Malizia

Bassani

Bazzano

et al. 2012

Monthly Notices of the Royal Astronomical Society

126

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“…Its AGN activity has been monitored in different spectral bands (see e.g. Dultzin-Hacyan et al 1992;Leighly et al 1996;Pronik et al 1997;Wanders et al 1997;Collier et al 1998;Nandra et al 1998;Pronik 2009;Pérez-Torres et al 2009;Artamonov et al 2010;Doroshenko et al 2010;Ugolkova & Artamonov 2011;Peterson et al 2014;Baldi et al 2015) NGC 7469 is probably interacting with another galaxy, IC 5283, that is about 60-70 Mpc far away (see, e.g. Marquez & Moles 1994).…”

Section: Introductionmentioning

confidence: 99%

“…Around the active nucleus, a bright circumnuclear ring is located at an angular distance of 2.5 arcsec (or ∼1 kpc) from the nucleus. The stellar ring shows star-forming activity (starburst region, see Wilson et 19992003200520092011 Figure 1. Light-curves of the photometry magnitudes in the B, V, R filters, transformed into corresponding fluxes using the equations from Dietrich et al (1998).…”

Section: Introductionmentioning

confidence: 99%

Long-term optical spectral monitoring of NGC 7469

Shapovalova¹,

Chavushyan²,

Afanasiev³

et al. 2017

Mon. Not. R. Astron. Soc.

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We present the results of the long-term (20-year period, from 1996 to 2015) optical spectral monitoring of the Seyfert 1 galaxy NGC 7469. The variation in the lightcurves of the broad He II λ4686Å Hβ and Hα lines, and the continuum at 5100Å and 6300Å have been explored. The maximum of activity was in 1998, and the variability in the continuum and lines seems to have two periods of around 1200 and 2600 days, however these periodicities should be taken with caution because of the red-noise. Beside these periods, there are several short-term (1-5 days) flare-like events in the light-curves. There are good correlations between the continuum fluxes and Hα and Hβ line fluxes, but significantly smaller correlation between the He II and continuum. We found that the time-lags between the continuum and broad lines are different for Hβ (∼ 20 l.d.) and Hα (∼ 3 l.d.), and that He II also has a smaller lag (∼2-3 l.d.). The Hα and Hβ line profiles show a slight red asymmetry, and the broad line profiles did not changed in the 20-year period. Using the lags and widths of Hα and Hβ we estimated the central black hole mass and found that it is ∼ (1 − 6) · 10 7 M ⊙ , which is in agreement with previous reverberation estimates.

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The dynamics of the broad-line region in NGC 3227

Devereux

2020

Monthly Notices of the Royal Astronomical Society

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Archival Hubble Space Telescope (HST) observations of the Seyfert 1 nucleus of NGC 3227 obtained with the Space Telescope Imaging Spectrograph (STIS) are re-examined in order to constrain a viable photoionization model for the broad-line region (BLR). The results imply that the BLR is a partially ionized, dust-free, spherical shell that is collapsing, supersonically, at the free-fall velocity due to its proximity to a supermassive black hole. The BLR is ionization bounded at the outer radius, coincident with the dust reverberation radius, and transforms into an X-ray emitting plasma inside the Balmer reverberation radius as the central UV–X-ray source is approached. Only 40 M⊙ of Hydrogen are required to explain the Balmer emission line luminosity, but it is compressed by gravity into a column measuring 5.5 × 1024 atoms cm−2. Assuming radiatively inefficient accretion, the X-ray luminosity requires ∼ 10−2 M⊙ yr−1. However, the mass inflow rate required to explain the luminosity of the broad Hα emission line is ∼ 1 M⊙ yr−1. The very large disparity between these two estimates indicates that 99% of the inflowing gas must be re-directed into an outflow, and on a very short timescale corresponding to ∼ 40 years. Alternatively, the radiative efficiency of the inflow has been overestimated, or the X-ray luminosity has been underestimated; a distinct possibility if the BLR is indeed Compton thick.

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Signs of gas flows in the variable Balmer line profiles of the Seyfert galaxy nuclei NGC 3227 and NGC 7469

Cited by 4 publications

References 15 publications

TheINTEGRAL/IBIS AGN catalogue - I. X-ray absorption properties versus optical classification

TheINTEGRAL/IBIS AGN catalogue - I. X-ray absorption properties versus optical classification

Long-term optical spectral monitoring of NGC 7469

The dynamics of the broad-line region in NGC 3227

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