X-Ray Spectra of Narrow-Line Seyfert 1 Galaxies in Comparison with Galactic Black Holes

2004 ◽  
Vol 155 ◽  
pp. 389-390
Author(s):  
Mio M. Murashima ◽  
Aya Kubota ◽  
Kazuo Makishima
Keyword(s):  
Black Holes ◽  
Narrow Line ◽  
X Ray

scholarly journals Ultrasoft Narrow-line Seyfert 1 Galaxies: An Extreme of Accretion onto Supermassive Black Holes

2000 ◽  
Vol 195 ◽  
pp. 207-208
Author(s):  
W. N. Brandt
Keyword(s):  
Black Holes ◽  
Supermassive Black Holes ◽  
High Mass ◽  
General Context ◽  
Narrow Line ◽  
X Ray ◽  
Basic Properties ◽  
The Future ◽  
Accretion Rates ◽  
New Phenomena

X-ray studies of ultrasoft narrow-line Seyfert 1 galaxies are revealing surprising new phenomena that are expanding our understanding of Seyfert activity, and they may well allow us to observe the effects of high mass accretion rates onto supermassive black holes. I briefly review the basic properties of these galaxies, their importance in a general context, and the prospects for studying them further in the future.

MATTER UNDER STRONG GRAVITY

2007 ◽  
Vol 16 (04) ◽  
pp. 1083-1091
Author(s):  
THOMAS BOLLER
Keyword(s):  
Black Holes ◽  
Accretion Disc ◽  
High Density ◽  
Narrow Line ◽  
X Ray ◽  
Strong Gravity ◽  
Partial Covering ◽  
Density Matter

I report on the discovery of high density matter in the immediate vicinity of the central black holes in the Narrow-Line Seyfert 1 Galaxies 1H 0707-495 and IRAS 13224–3809. The density of these clouds is of the order of 1019 cm -3. The clouds are neutral for Fe and must be embedded into the accretion disc to explain the observations. This results in a partial covering interpretation, where the clouds partially absorb the emission from the accretion disc and part of the emission reaches the observer unabsorbed, leading to a strong soft excess, a sharp Fe K edge without any detectable Fe K reemission. This scenario has been proposed theoretically first by M. Rees in 1987 and appears now to be observationally confirmed with observations of the X-ray observatory XMM-Newton.

scholarly journals Relativistic Fe Kα line and ensemble spins of black holes in narrow-line Seyfert 1 galaxies

2014 ◽  
Vol 10 (S312) ◽  
pp. 39-42
Author(s):  
Weimin Yuan ◽  
Zhu Liu ◽  
Youjun Lu ◽  
Xin-Lin Zhou
Keyword(s):  
Black Holes ◽  
Seyfert Galaxies ◽  
Emission Feature ◽  
Narrow Line ◽  
Massive Black Holes ◽  
X Ray ◽  
Accretion Rates ◽  
Black Hole Growth ◽  
Average Spin ◽  
Hole Growth

AbstractWhile a broad line of the Fe Kα emission is commonly found in the X-ray spectra of typical Seyfert galaxies, the situation is unclear in the case of Narrow Line Seyfert 1 galaxies (NLS1s)—an extreme subset which are generally thought to harbor less massive black holes with higher accretion rates. We report results of our study of the assemble property of the Fe K line in NLS1s by stacking the X-ray spectra of a large sample of 51 NLS1s observed with XMM-Newton. We find in the stacked X-ray spectra a prominent, broad emission feature over 4–7 keV, which is characteristic of the broad Fe Kα line. Our results suggest that a relativistic broad Fe line may in fact be common in NLS1s. The line profile is used to study the average spin of the black holes in the sample. We find, for the first time, that their black holes are constrained to be likely spinning at averagely low or moderate rates as a population. The implications of the results are discussed in the context of the black hole growth in NLS1 galaxies.

scholarly journals A Link Between Seyfert Emission-Line Widths and X-Ray Continuum Slopes

1997 ◽  
Vol 159 ◽  
pp. 248-251
Author(s):  
Th. Boile ◽  
W.N. Brandt
Keyword(s):  
Black Holes ◽  
Power Law ◽  
Optical Emission ◽  
Emission Lines ◽  
Narrow Line ◽  
Rapid Variability ◽  
X Ray ◽  
Accretion Rates ◽  
Line Widths ◽  
Almost All

AbstractThis paper reports on AGN with extremely soft X-ray spectra observed with ROSAT. From their optical emission lines, these objects are classified as narrow-line Seyfert 1 galaxies (NLSl), almost all with extremely large Fe II/Hβ flux ratios and relatively narrow optical lines of hydrogen. NLSl have generally steeper soft X-ray continuum slopes than normal Seyfert 1s, and there may exist an anticorrelation between 0.1–2.4 keV continuum slope and the FWHM of the Hβ line. Objects with steep 0.1–2.4 keV continuum slopes and Hβ FWHM > 3000 km s−1 are clearly discriminated against by nature. When simple power-law models are fit to the data, photon indices reach values up to about 5, much higher than is usually seen in Seyfert 1s. Models with smaller-mass black holes and/or higher accretion rates show some promise to explain the relation between the FWHM of the Hβ line and the X-ray continuum slope. We further report evidence for persistent giant and rapid variability in the ultrasoft narrow-line Seyfert 1 galaxy IRAS 13224–3809.

scholarly journals X-Ray Spectra of the Narrow-Line Seyfert 1 Galaxy Ton S180 in Comparison with Galactic Black Holes

2005 ◽  
Vol 57 (2) ◽  
pp. 279-285 ◽  
Author(s):  
MURASHIMA Mio ◽  
Aya Kubota ◽  
Kazuo Makishima ◽  
Motohide Kokubun ◽  
Soojing Hong ◽  
...  
Keyword(s):  
Black Holes ◽  
Narrow Line ◽  
X Ray

scholarly journals X-ray properties of reverberation-mapped AGNs with super-Eddington accreting massive black holes

2019 ◽  
Vol 15 (S356) ◽  
pp. 143-143
Author(s):  
Jaya Maithil ◽  
Michael S. Brotherton ◽  
Bin Luo ◽  
Ohad Shemmer ◽  
Sarah C. Gallagher ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Accretion Rate ◽  
Time Lags ◽  
Black Hole Mass ◽  
Host Galaxies ◽  
Massive Black Holes ◽  
X Ray ◽  
Photon Index ◽  
The Impact

AbstractActive Galactic Nuclei (AGN) exhibit multi-wavelength properties that are representative of the underlying physical processes taking place in the vicinity of the accreting supermassive black hole. The black hole mass and the accretion rate are fundamental for understanding the growth of black holes, their evolution, and the impact on the host galaxies. Recent results on reverberation-mapped AGNs show that the highest accretion rate objects have systematic shorter time-lags. These super-Eddington accreting massive black holes (SEAMBHs) show BLR size 3-8 times smaller than predicted by the Radius-Luminosity (R-L) relationship. Hence, the single-epoch virial black hole mass estimates of highly accreting AGNs have an overestimation of a factor of 3-8 times. SEAMBHs likely have a slim accretion disk rather than a thin disk that is diagnostic in X-ray. I will present the extreme X-ray properties of a sample of dozen of SEAMBHs. They indeed have a steep hard X-ray photon index, Γ, and demonstrate a steeper power-law slope, ασx.

scholarly journals The radio-loud narrow-line Seyfert 1 galaxy 1H 0323+342 in a galaxy merger

2020 ◽  
Vol 496 (2) ◽  
pp. 1757-1765 ◽  
Author(s):  
Akihiro Doi ◽  
Motoki Kino ◽  
Nozomu Kawakatu ◽  
Kazuhiro Hada
Keyword(s):  
Black Holes ◽  
Near Infrared ◽  
Gamma Ray ◽  
Linear Structure ◽  
Seyfert Galaxies ◽  
Mass Function ◽  
High Mass ◽  
Host Galaxy ◽  
Supporting Evidence ◽  
Narrow Line

ABSTRACT The supermassive black holes (SMBHs) of narrow-line Seyfert 1 galaxies (NLS1s) are at the lower end of the mass function of active galactic nuclei (AGNs) and reside preferentially in late-type host galaxies with pseudobulges, which are thought to be formed by internal secular evolution. On the other hand, the population of radio-loud NLS1s presents a challenge for the relativistic jet paradigm, which states that powerful radio jets are associated exclusively with very high mass SMBHs in elliptical hosts, which are built up through galaxy mergers. We investigated distorted radio structures associated with the nearest gamma-ray-emitting, radio-loud NLS1, 1H 0323+342. This provides supporting evidence for the merger hypothesis based on past optical/near-infrared observations of its host galaxy. The anomalous radio morphology consists of two different structures: the inner curved structure of the currently active jet and an outer linear structure of low-brightness relics. Such coexistence might be indicative of the stage of an established black hole binary with precession before the black holes coalesce in the galaxy merger process. 1H 0323+342 and other radio-loud NLS1s under galaxy interactions may be extreme objects on the evolutionary path from radio-quiet NLS1s to normal Seyfert galaxies with larger SMBHs in classical bulges through mergers and merger-induced jet phases.

scholarly journals The formation of high-mass black holes in low-mass X-ray binaries

New Astronomy ◽  
1999 ◽  
Vol 4 (4) ◽  
pp. 313-323 ◽  
Author(s):  
G.E. Brown ◽  
C.-H. Lee ◽  
Hans A. Bethe
Keyword(s):  
Black Holes ◽  
High Mass ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries
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