Differences in the emission line spectrum at maximum and minimum of the nuclear brightness of the Seyfert galaxy NGC 7469

Pronik, I. I.; Metik, L. P.; Меркулова, Н. И.

doi:10.1007/bf00653770

Cited by 4 publications

(12 citation statements)

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“…The deep nuclear minimum is a rare and peculiar event that lasts for 2-3 months. According to Chuvaev et al (1990) and Pronik et al (1996), the brightness of the NGC 7469 nucleus, by Pronik et al (1996Pronik et al ( , 1997 and maximum in October 1975 by Barbieri et al (1977). The four individual components are the same as in Fig.…”

Section: Deep Minimum As a Peculiar Event During The Agns Variatiabilitymentioning

confidence: 88%

“…During minimum brightness components "a", "b" and "d" are seen as shoulders. Figure 10 compares the H β line profiles obtained during a minimum of the nucleus brightness on January 13-15, 1977, by Pronik et al (1996), and a deep minimum of the nucleus brightness on October 5, 1989, by Chuvaev et al (1990). Components "a" and "b", observed during deep minimum of the nucleus brightness, on October 5, 1989, are seen as emission, and component "d" as a shoulder.…”

Section: Compiled Data For Ngc 7469mentioning

confidence: 97%

“…Intensity of continuum variations in the nucleus of NGC 7469 exhibit ordinary maxima and minima (or simply maxima and minima) within a diaphragm aperture of 5 diameter during of 3-5 years differing by about a factor of 5 (Pronik et al 1996). A peculiar event, i.e.…”

Section: Long-term Variation Of the Balmer Lines Of The Seyfert 1 Nucmentioning

confidence: 97%

“…Optical brightness of the NGC 7469 nucleus within a diaphragm aperture of 5 diameter has changed from ordinary minimum to deep minimum by about a factor of 10. (Pronik et al 1996). Pecular events -flares -often occured with duration of about several days both at minima and maxima of the nuclei brightness (Pronik & Metik 2004).…”

Section: Long-term Variation Of the Balmer Lines Of The Seyfert 1 Nucmentioning

confidence: 99%

“…Components "a" and "d" are discernible as emission or shoulders in the profiles. Figure 9 compares the H β profile obtained during the maximum of the nucleus brightness on October 25, 1975, by Barbieri et al (1977), and at minimum nucleus brightness on January 13-15, 1977, by Pronik et al (1996Pronik et al ( , 1997. Normalisation of the intensities of the H β profile in Fig.…”

Section: Compiled Data For Ngc 7469mentioning

confidence: 99%

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

Pronik

2009

A&A

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The data on the variable Balmer line profiles obtained by us for the Seyfert galaxy NGC 3227 and NGC 7469 nuclei and published separately during , were combined with the data compiled from literature, and reviewed in this paper. We hypothesize that the profile variations are connected with three independent regions of different physical conditions: 1) Classical broad line region (BLR) of size ∼4.5 × 10 16 cm is ionized and excited by the central source radiation. The central source brightness variations in 1971-1972 produced gas parameter variations of 10 9 cm −3 ≥ n e ≥ 10 8 cm −3 and 2 × 10 4 K ≤ T e ≤ 4 × 10 4 K. 2) The profiles of the Balmer lines contain narrow components that have retained their positions (radial velocities) over 25 and 17 years in NGC 3227 and NGC 7469, respectively. These components are supposed to be caused by long-lived gas flows in the nuclei of the galaxies. Observational data acquired by Rubin and Ford allow us to assume that gas in the flows can be explained by models of collision ionization and excitation of gas with self-absorption. It is dense and hot plasma with n e = 10 8 -10 12 cm −3 and T e = (1−2.5) × 10 4 K. 3) Broad blue bumps of radial velocities between -4000 km s −1 and -5000 km s −1 were detected in the Hγ profile during a several day flare twice in NGC 3227 nucleus and once in NGC 7469. One can speculate that the flares are connected with short-lived ejections. The gas in the ejections was ionized and excited by collision processes with n e ∼ 10 14 cm −3 and T e ∼ 25 000 K.

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Section: Deep Minimum As a Peculiar Event During The Agns Variatiabilitymentioning

confidence: 88%

Section: Compiled Data For Ngc 7469mentioning

confidence: 97%

Section: Long-term Variation Of the Balmer Lines Of The Seyfert 1 Nucmentioning

confidence: 97%

Section: Long-term Variation Of the Balmer Lines Of The Seyfert 1 Nucmentioning

confidence: 99%

Section: Compiled Data For Ngc 7469mentioning

confidence: 99%

See 3 more Smart Citations

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

Pronik

2009

A&A

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Signs of Flows and Shocks in Variable Balmer Line Profiles of the Seyfert Galaxies NGC 3227 and NGC 7469

Pronik

Metik

2003

Astronomical & Astrophysical Transactions

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There is a widely held opinion that the narrow components of the emission line profiles in the spectra of AGNs are produced by gas streams and flows. The spectral data obtained and collected for the Seyfert galaxies NGC 3227 and NGC 7469 showed that the profiles of the Balmer lines contain components that maintained their positions over 9-25 years. We suppose that the components can be caused by long-lived flows or jets in broad-line regions. Night-to-night variations in the emission line H b and H g profiles over 3 days were detected. We suppose that short-term variability of the Balmer lines can be produced in short-lived shocks in gas flows or jets.

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[ITAL]UBVRI[/ITAL] Light Curves of the Seyfert Galaxy NGC 7469 During 1990–1998: Microvariability

Меркулова

2000

The Astronomical Journal

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Differences in the emission line spectrum at maximum and minimum of the nuclear brightness of the Seyfert galaxy NGC 7469

Cited by 4 publications

References 40 publications

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

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

Signs of Flows and Shocks in Variable Balmer Line Profiles of the Seyfert Galaxies NGC 3227 and NGC 7469

[ITAL]UBVRI[/ITAL] Light Curves of the Seyfert Galaxy NGC 7469 During 1990–1998: Microvariability

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