The size of the broad-line region in the Seyfert galaxy NGC 4151

1988 ◽  
Vol 330 ◽  
pp. 111 ◽  
Author(s):  
Bradley M. Peterson ◽  
Stephen A. Cota
Keyword(s):  
Seyfert Galaxy ◽  
Broad Line ◽  
Ngc 4151 ◽  
Broad Line Region ◽  
Line Region

scholarly journals Reverberation Mapping Analysis of the Broad-Line Region in Seyfert Galaxy NGC 4151

1998 ◽  
Vol 188 ◽  
pp. 424-425
Author(s):  
S.J. Xue ◽  
F.Z. Cheng
Keyword(s):  
Emission Line ◽  
Time Lag ◽  
Seyfert Galaxy ◽  
Broad Line ◽  
Reverberation Mapping ◽  
Ngc 4151 ◽  
Broad Line Region ◽  
Spectroscopic Monitoring ◽  
Line Region ◽  
The Continuum

One of the primary goals of AGN variability studies has been to determine the size of broad-line region (BLR) through the reverberation mapping technique. In a recent international multiwavelength spectroscopic monitoring campaign, NGC 4151 has been observed intensively by ground-based telescopes for a period of over 2 months, with a typical temporal resolution of 1 day. The main result from this optical campaign is that finding the variation in the emission line flux (Hβ or Hα) lagging the continuum by 0-3 days (1993 campaign: Kaspi et al. 1996). This is in contrast to the past results in which a time lag of 9±2 days was found for the same emission line (1988 campaign: Maoz et al. 1991). Such a BLR “size problem” may be caused by a different variability timescale of the ionizing continuum or a real change in BLR gas distribution in the 5.5 yr interval between the two watch campaigns. In order to clarify which of the two possibilities is most likely the real case, we performed further reverberation analysis on both optical datasets.

scholarly journals X-Ray Structure between the Innermost Disk and Optical Broad-line Region in NGC 4151

2018 ◽  
Vol 865 (2) ◽  
pp. 97 ◽  
Author(s):  
J. M. Miller ◽  
E. Cackett ◽  
A. Zoghbi ◽  
D. Barret ◽  
E. Behar ◽  
...  
Keyword(s):  
Broad Line ◽  
X Ray ◽  
Ngc 4151 ◽  
Broad Line Region ◽  
Line Region

The structure of the broad-line region in the Seyfert galaxy Markarian 590

1993 ◽  
Vol 402 ◽  
pp. 469 ◽  
Author(s):  
Bradley M. Peterson ◽  
Babar Ali ◽  
Keith Horne ◽  
Ray Bertram ◽  
Nancy J. Lame ◽  
...  
Keyword(s):  
Seyfert Galaxy ◽  
Broad Line ◽  
Broad Line Region ◽  
Line Region

scholarly journals 11.6. Spectral monitoring of AGN at the 6 meter telescope

1998 ◽  
Vol 184 ◽  
pp. 467-468
Author(s):  
N.G. Bochkarev ◽  
A.I. Shapovalova ◽  
A.N. Burenkov ◽  
V.V. Vlasyuk
Keyword(s):  
Special Astrophysical Observatory ◽  
Broad Line ◽  
North Caucasus ◽  
Ngc 4151 ◽  
Broad Line Region ◽  
Line Region ◽  
Ngc 5548 ◽  
Spectral Monitoring ◽  
Ngc 7469

To study broad line region (BLR) size and kinematics spectral monitoring of NGC 3516, NGC 4151, NGC 5548, NGC 7469 and 3C390.3 has been performed with the 6 m telescope of the Special Astrophysical Observatory (N. Arkhyz- North Caucasus) in 1986–1996. The spectra are obtained in the Nasmyth focus using the TV scanner with a resolution of 3–4Å and S/N= 10–25 within 4000–5200ÅÅ (1986–94, 500 spectra), and in the prime focus with the spectrograph UAGS (a long-slit mode) + CCD (resolution 5–10Å) or multi-pupil field spectrograph (MPFS) + CCD (resolution 4Å) within 4000–7000ÅÅ and S/N=50–100 (1995–96, 270 spectra).

High-rate active galaxy monitoring at the Wise Observatory. III - The broad-line region of NGC 4151

1991 ◽  
Vol 367 ◽  
pp. 493 ◽  
Author(s):  
D. Maoz ◽  
H. Netzer ◽  
T. Mazeh ◽  
S. Beck ◽  
E. Almoznino ◽  
...  
Keyword(s):  
Active Galaxy ◽  
High Rate ◽  
Broad Line ◽  
Ngc 4151 ◽  
Broad Line Region ◽  
Line Region

scholarly journals NGC 3147: a ‘true’ type 2 Seyfert galaxy without the broad-line region

2008 ◽  
Vol 385 (1) ◽  
pp. 195-199 ◽  
Author(s):  
S. Bianchi ◽  
A. Corral ◽  
F. Panessa ◽  
X. Barcons ◽  
G. Matt ◽  
...  
Keyword(s):  
Seyfert Galaxy ◽  
Broad Line ◽  
Broad Line Region ◽  
Line Region ◽  
True Type

scholarly journals Analyzing temporal variations of AGN emission line profiles in the context of (dusty) cloud structure formation in the broad line region

2019 ◽  
Vol 621 ◽  
pp. A46 ◽  
Author(s):  
J. Esser ◽  
J.-U. Pott ◽  
H. Landt ◽  
W. D. Vacca
Keyword(s):  
Active Galactic Nuclei ◽  
Accretion Disk ◽  
Galactic Nuclei ◽  
Temporal Variations ◽  
Cloud Formation ◽  
Broad Line ◽  
Ngc 4151 ◽  
Broad Line Region ◽  
The Past ◽  
Line Region

The formation processes and the exact appearance of the dust torus and broad line region (BLR) of active galactic nuclei (AGN) are under debate. Theoretical studies show a possible connection between the dust torus and BLR through a common origin in the accretion disk. However observationally the dust torus and BLR are typically studied separately. NGC 4151 is possibly one of the best suited Seyfert 1 galaxies for simultaneous examinations because of its high number of both photometric and spectroscopic observations in the past. Here we compare changes of the dust radius to shape variations of broad emission lines (BEL). While the radius of the dust torus decreased by almost a factor of two from 2004 to 2006 shape variations can be seen in the red wing of BELs of NGC 4151. These simultaneous changes are discussed in a dust and BEL formation scheme. We also use the BEL shape variations to assess possible cloud distributions, especially in azimuthal direction, which could be responsible for the observed variations. Our findings can best be explained in the framework of a dust inflated accretion disk. The changes in the BELs suggest that this dusty cloud formation does not happen continuously, and over the whole accretion disk, but on the contrary in spatially confined areas over rather short amount of times. We derive limits to the azimuthal extension of the observed localized BEL flux enhancement event.

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