scholarly journals The Balmer lines in the Seyfert Galaxies NGC 5548 and NGC 4151

1972 ◽  
Vol 44 ◽  
pp. 155-159
Author(s):  
R. Weymann ◽  
R. Cromwell
Keyword(s):  
Electron Scattering ◽  
Small Volume ◽  
Seyfert Galaxies ◽  
Ngc 4151 ◽  
Transient Nature ◽  
Balmer Lines ◽  
Ngc 5548

The profiles of the Balmer lines in NGC 5548 as reported by Dibai et al. (1968) were somewhat asymmetric, whereas those reported by Anderson (1970) are smooth and symmetric. We present profiles which are strongly asymmetric, resembling those of Dibai et al. Evidently electron scattering is not the sole principal broadening agent and we must deal with velocities ∼ 2500 km s−1 in a very small volume.The transient nature of the P-Cygni type profiles in the Balmer lines of NGC 4151 has previously been noted (Cromwell and Weymann, 1970). These lines have since disappeared, at the resolution available to us, in a time of 3 months. A model in which frequent outbursts of shells or filaments produce transient features in the Balmer lines, while the accumulated material from past outbursts produces the relatively stable HeI λ 3889 feature, seems the most plausible.

scholarly journals Flows and Shocks in Variable Fluxes of Seyfert galaxies

2004 ◽  
Vol 217 ◽  
pp. 360-361
Author(s):  
I. I. Pronik
Keyword(s):  
Seyfert Galaxies ◽  
Energy Output ◽  
Balmer Line ◽  
Gas Flows ◽  
Line Profiles ◽  
Short Term ◽  
Ngc 4151 ◽  
Balmer Lines ◽  
Ngc 1275 ◽  
Ngc 7469

Data collected from the optical through infrared to the radio show that the Seyfert galaxies NGC 1275, NGC 3227, NGC 4151, NGC 5548 and NGC 7469 exhibit signs of flows or jets. The characteristics of night-to-night variations of Balmer line profiles and/or intranight continuum variations were obtained and investigated at the Crimean Astrophysical Observatory. They permit to suppose, that short term variability of the Balmer lines and intranight continuum variations can be produced in short lived shocks as a result of strong energy output in the form of gas flows or jets.

Photometric Studies of the Seyfert Galaxies NGC 3516, NGC 5548, NGC 3227, NGC 4051, NGC 4151, and NGC 7469

Astrophysics ◽  
2019 ◽  
Vol 62 (2) ◽  
pp. 163-176
Author(s):  
S. A. Shomshekova ◽  
E. K. Denissyuk ◽  
R. R. Valiullin ◽  
I. V. Reva ◽  
A. V. Kusakin
Keyword(s):  
Seyfert Galaxies ◽  
Ngc 4151 ◽  
Ngc 5548 ◽  
Ngc 4051 ◽  
Ngc 7469

NGC 4151 and MCG 8-11-11: Two X-Ray Seyfert Galaxies with Strong Soft γ-Ray Emission

1981 ◽  
pp. 107-112
Author(s):  
L. Bassani ◽  
R. C. Butler ◽  
A. J. Dean ◽  
G. Di Cocco ◽  
N. A. Dipper ◽  
...  
Keyword(s):  
Seyfert Galaxies ◽  
X Ray ◽  
Ngc 4151 ◽  
Γ Ray

scholarly journals Line-Profile Variations in AGN

1997 ◽  
Vol 159 ◽  
pp. 201-202
Author(s):  
W. Kollatschny ◽  
M. Dietrich
Keyword(s):  
Line Profile ◽  
Seyfert Galaxies ◽  
Line Segments ◽  
Ngc 5548 ◽  
Individual Line

AbstractLine-profile variations in the Seyfert galaxies NGC 5548 and NGC 4593 are discussed. The variations of individual line segments are different from line to line and from outburst to outburst.

A Study of the Seyfert Galaxy NGC 4151

1967 ◽  
Vol 1 (1) ◽  
pp. 7-7 ◽  
Author(s):  
J. B. Oke ◽  
Wallace L. W. Sargent
Keyword(s):  
Continuous Spectrum ◽  
Seyfert Galaxy ◽  
Seyfert Galaxies ◽  
Radio Galaxies ◽  
Emission Lines ◽  
Ngc 4151 ◽  
Broad Emission ◽  
Ngc 1068 ◽  
Stellar Sources ◽  
No Absorption

The small group of known Seyfert galaxies (Seyfert 1943) is of interest because it is clear that some violent activity is occurring in the nucleus, and some of the properties suggest a relationship with quasi-stellar sources. The spectrum of a Seyfert galaxy consists of strong, often very broad, emission lines superposed on a continuous spectrum which in some cases shows no absorption-line features. Two of the galaxies, NGC 1068 and 1275, are radio galaxies and the latter is known to be variable at radio frequencies (Dent 1966).

scholarly journals Survey of Milliarcsec Structure in Eight Seyfert Galaxies: Results on NGC 1068 and NGC 4151

1998 ◽  
Vol 164 ◽  
pp. 301-302 ◽  
Author(s):  
A. L. Roy ◽  
J. S. Ulvestad ◽  
E. J. M. Colbert ◽  
A. S. Wilson ◽  
R. P. Norris
Keyword(s):  
Spectral Index ◽  
Low Frequency ◽  
Seyfert Galaxies ◽  
Scale Structure ◽  
Scale Morphology ◽  
Ngc 4151 ◽  
Ngc 1068

AbstractWe are surveying eight nearby Seyfert galaxies (four Sy1s and four Sy2s) that have compact radio cores, using the VLBA. We are interested in parsec-scale morphology and low-frequency absorption effects, and so are observing four frequencies (1.6, 4.8, 8.4 and 15 GHz) to get spectral-index diagnostics. In this paper, we present results on two galaxies, NGC 1068 and NGC 4151. NGC 4151 shows a curved radio jet on the sub-parsec scale, with the smallest scale structure misaligned by 55° from the jet on scales of parsecs to hundreds of parsecs. NGC 1068 contains several components in the inner tens of parsecs, with those components showing a variety of absorption and resolution effects.

Extended soft X-ray emission in Seyfert galaxies: ROSAT HRI observations of NGC 3516, NGC 4151, and Markarian 3

1995 ◽  
Vol 439 ◽  
pp. 121 ◽  
Author(s):  
Jon A. Morse ◽  
Andrew S. Wilson ◽  
Martin Elvis ◽  
Kimberly A. Weaver
Keyword(s):  
Seyfert Galaxies ◽  
X Ray ◽  
Ngc 4151
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