Night-to-night variation in the optical emission lines in the nuclear spectrum of the Seyfert galaxy NGC 3227

Pronik, I. I.; Metik, L. P.

doi:10.1080/10556790500049450

Cited by 4 publications

(2 citation statements)

References 23 publications

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“…Pronik and Metik have reviewed [1] studies of the variability in the emission from the nucleus of the Seyfert galaxy NGC 3227, whose Seyfert type varies with time. Spectral and photometric monitorings of the nucleus of NGC 3227 reveals significant variations in the intensity of continuum emission and emission lines with time.…”

Section: Introductionmentioning

confidence: 99%

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Night-to-night variability of the emission lines in the spectrum of the Seyfert galaxy NGC 3227 nucleus

2006

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This is a study of optical emission lines of the nucleus of the Seyfert galaxy NGC 3227. This work is based on53 spectrograms obtained with the 6-m telescope at the brightness maximum of this galactic nucleus on January 12-15, 1977. A set of profiles of the hydrogen H α , H β , and H γ lines and the equivalent widths ( λ EW ) of six emission lines and blends averaged over series of observations are presented. Broadening of the hydrogen line profiles was observed over the three days. At a level of 0.50 times the peak brightness the hydrogen line profiles were broadened by 12%, 35%, and 44%, respectively. The broadening of the H β line was accompanied by a reduction in its equivalent width ( β EW ). It is suggested that a flare was observed in the nucleus of the galaxy on a time scale of 3 days, possibly caused to a shock wave in long-lived flows from the galaxy nucleus.

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Section: Introductionmentioning

confidence: 99%

“…Original article submitted July 7, 2006 Based on part of the spectral data obtained on the 6-m telescope over January 12-15, 1977, Pronik and Metik [1] found that:…”

Section: Introductionmentioning

confidence: 99%

Night-to-night variability of the emission lines in the spectrum of the Seyfert galaxy NGC 3227 nucleus

2006

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The Emission Spectrum Characteristics of the Seyfert Galaxy NGC7469 Nucleus Over Time of Decades

Sharipova

2018

Astrophysics

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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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Night-to-night variation in the optical emission lines in the nuclear spectrum of the Seyfert galaxy NGC 3227

Cited by 4 publications

References 23 publications

Night-to-night variability of the emission lines in the spectrum of the Seyfert galaxy NGC 3227 nucleus

Night-to-night variability of the emission lines in the spectrum of the Seyfert galaxy NGC 3227 nucleus

The Emission Spectrum Characteristics of the Seyfert Galaxy NGC7469 Nucleus Over Time of Decades

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

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