The International Cooperation of the Crimean Astrophysical Observatory on the Spectral and Photometric Monitoring of Active Galactic Nuclei

Pronik, V. I.

doi:10.1080/1055679031000096909

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“…In this paper, we present variations in the emission H α , H β and H γ line profiles obtained during 5 epochs over 25 years in 1967-1992 for NGC 3227, and during 6 epochs over 17 years in 197217 years in -1989 Since 1971 spectral monitoring of two bright galaxies in the Seyfert list (Seyfert 1943), NGC 3227 and NGC 7469, was carried out with two telescopes. Spectra for NGC 3227 in 1971-1981and for NGC 7469 in 1971-1972 were acquired by the high speed spectrograph mounted on 2.6-m Shain telescope of Crimean Astrophysical Observatory (Pronik 1971(Pronik , 1983(Pronik , 1975a. In January 1977, spectra for both nuclei were obtained at prime focus of the 6-m telescope of Special Astrophysical Observatory of USSR.…”

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confidence: 99%

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: Introductionmentioning

confidence: 99%

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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show abstract

The International Cooperation of the Crimean Astrophysical Observatory on the Spectral and Photometric Monitoring of Active Galactic Nuclei

Cited by 1 publication

References 11 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

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