scholarly journals SPECTRAL AND PHOTOMETRIC STUDY OF THE SEYFERT GALAXY NGC 5548

2021 ◽  
Vol 3 (337) ◽  
pp. 40-49
Author(s):  
E.K. Denissyuk ◽  
G.K. Aimanova ◽  
S.A. Shomshekova ◽  
I.V. Reva ◽  
M.A. Krugov
Keyword(s):  
Seyfert Galaxy ◽  
Photometric Study ◽  
Ngc 5548

Radio Emission from the Seyfert Galaxy NGC 5548

1982 ◽  
pp. 191-192
Author(s):  
J. S. Ulvestad ◽  
A. S. Wilson ◽  
D. G. Wentzel
Keyword(s):  
Radio Emission ◽  
Seyfert Galaxy ◽  
Ngc 5548

scholarly journals Variability of the Ultraviolet Continuum and Emission Lines of NGC 3783

1994 ◽  
Vol 159 ◽  
pp. 403-403
Author(s):  
G.A. Reichert
Keyword(s):  
Seyfert Galaxy ◽  
Light Curves ◽  
Emission Lines ◽  
Power Density Spectrum ◽  
Ultraviolet Continuum ◽  
Density Spectrum ◽  
International Ultraviolet Explorer ◽  
Monitoring Effort ◽  
Ngc 5548 ◽  
The Continuum

On behalf of the International AGN Watch, I report on the results of intensive ultraviolet spectral monitoring of the Seyfert 1 galaxy NGC 3783. The nucleus of NGC 3783 was observed with the International Ultraviolet Explorer satellite on a regular basis for a total of seven months, once every 4 days for the first 172 days and once every other day for the final 50 days. Significant variability was observed in both continuum and emission-line fluxes. The light curves for the continuum fluxes exhibited two well-defined local minima or “dips,” the first lasting ≲ 20 days and the second ≲ 4 days, with additional episodes of relatively rapid flickering of approximately the same amplitude. As in the case of NGC 5548 (the only other Seyfert galaxy that has been the subject of such an intensive, sustained monitoring effort), the largest continuum variations were seen at the shortest wavelengths, so that the continuum became “harder” when brighter. The variations in the continuum occurred simultaneously at all wavelengths (Δt < 2 days). Generally, the amplitude of variability of the emission lines was lower than (or comparable to) that of the continuum. Apart from Mg II (which varied little) and N V (which is relatively weak and badly blended with Lyα) the light curves of the emission lines are very similar to the continuum light curves, in each case with a small systematic delay or “lag.” As for NGC 5548, the highest ionization lines seem to respond with shorter lags than the lower ionization lines. The lags found for NGC 3783 are considerably shorter than those obtained for NGC 5548, with values of (formally) ∼ 0 days for He II+O III], and ∼ 4 days for Lyα, and C IV. The data further suggest lags of ∼ 4 days for Si IV+O IV], and 8–30 days for Si III]+C III]. Uncertainties in these quantities are likely to be of order 2–3 days for the stronger features (Lyα, C IV), and 3–4 days for the weaker ones (He II+O III], Si IV+O IV], Si III]+C III]). Mg II lagged the 1460 Å continuum by ∼ 9 days, although this result depends on the method of measuring the line flux, and may in fact be due to variability of the underlying Fe II lines. Correlation analysis further shows that the power density spectrum contains substantial unresolved power over time scales of ≲ 2 days, and that the character of the continuum variability may change with time.

Deep Optical Imaging of the Bright Seyfert Galaxy NGC 5548: A Long, Very Low Surface Brightness Tail

1998 ◽  
Vol 116 (1) ◽  
pp. 102-110 ◽  
Author(s):  
J. Anthony Tyson ◽  
Philippe Fischer ◽  
Puragra Guhathakurta ◽  
Peter McIlroy ◽  
Richard Wenk ◽  
...  
Keyword(s):  
Optical Imaging ◽  
Surface Brightness ◽  
Seyfert Galaxy ◽  
Low Surface Brightness ◽  
Ngc 5548

An accretion event in the Seyfert galaxy NGC 5548

Nature ◽  
1986 ◽  
Vol 324 (6095) ◽  
pp. 345-347 ◽  
Author(s):  
B. M. Peterson ◽  
G. J. Ferland
Keyword(s):  
Seyfert Galaxy ◽  
Ngc 5548

scholarly journals Iron line emission and variability in the X-ray spectrum of the Seyfert galaxy NGC 5548

1980 ◽  
Vol 193 (1) ◽  
pp. 15P-20P ◽  
Author(s):  
M. J. C. Hayes ◽  
J. L. Culhane ◽  
R. J. Blissett ◽  
P. Barr ◽  
S. J. B. Burnell
Keyword(s):  
Line Emission ◽  
Seyfert Galaxy ◽  
Iron Line ◽  
X Ray ◽  
Ngc 5548

scholarly journals Radio Emission from the Seyfert Galaxy NGC 5548

1982 ◽  
Vol 97 ◽  
pp. 191-192
Author(s):  
J. S. Ulvestad ◽  
A. S. Wilson ◽  
D. G. Wentzel
Keyword(s):  
High Resolution ◽  
Radio Emission ◽  
Radio Source ◽  
Seyfert Galaxy ◽  
Central Component ◽  
The Galaxy ◽  
Ngc 5548

Weak radio emission from the type 1.5 Seyfert galaxy NGC 5548 has been mapped with high resolution at the VLA at both 1465 and 4885 MHz. The galaxy contains the largest (5.9 kpc) triple radio source known in a Seyfert galaxy. The central component of that triple is unresolved (<0.39×0.15 kpc) and has a flatter spectrum than the well-resolved outer lobes. In addition, the field surrounding NGC 5548 and two of the sources in that field have been mapped at 1465 MHz; the field sources are unlikely to be physically associated with NGC 5548.

Variations of the ultraviolet Fe II and Balmer continuum emission in the Seyfert galaxy NGC 5548

1993 ◽  
Vol 404 ◽  
pp. 576 ◽  
Author(s):  
D. Maoz ◽  
H. Netzer ◽  
B. M. Peterson ◽  
J. Bechtold ◽  
R. Bertram ◽  
...  
Keyword(s):  
Seyfert Galaxy ◽  
Continuum Emission ◽  
Ngc 5548

Evidence for a supermassive black hole in the nucleus of the Seyfert galaxy NGC 5548

1990 ◽  
Vol 358 ◽  
pp. L37 ◽  
Author(s):  
D. Michael Crenshaw ◽  
James H., Jr. Blackwell
Keyword(s):  
Black Hole ◽  
Seyfert Galaxy ◽  
Supermassive Black Hole ◽  
Ngc 5548
Sign in / Sign up

Export Citation Format

Share Document