Growing Black Holes in Narrow-Line Seyfert 1 Galaxies

Author(s):  
D. Grupe ◽  
S. Mathur
Keyword(s):  
2020 ◽  
Vol 496 (2) ◽  
pp. 1757-1765 ◽  
Author(s):  
Akihiro Doi ◽  
Motoki Kino ◽  
Nozomu Kawakatu ◽  
Kazuhiro Hada

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.


2000 ◽  
Vol 195 ◽  
pp. 207-208
Author(s):  
W. N. Brandt

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.


2007 ◽  
Vol 16 (04) ◽  
pp. 1083-1091
Author(s):  
THOMAS BOLLER

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.


2014 ◽  
Vol 10 (S312) ◽  
pp. 39-42
Author(s):  
Weimin Yuan ◽  
Zhu Liu ◽  
Youjun Lu ◽  
Xin-Lin Zhou

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.


2013 ◽  
Vol 429 (3) ◽  
pp. 2594-2616 ◽  
Author(s):  
Laura Blecha ◽  
Abraham Loeb ◽  
Ramesh Narayan

2004 ◽  
Vol 155 ◽  
pp. 389-390
Author(s):  
Mio M. Murashima ◽  
Aya Kubota ◽  
Kazuo Makishima
Keyword(s):  

2009 ◽  
Vol 5 (S267) ◽  
pp. 338-338
Author(s):  
Dawei Xu ◽  
S. Komossa

AbstractGalaxies with low-mass black holes and high accretion rates, i.e., narrow-line Seyfert 1 (NLS1) galaxies, are important objects when addressing the issues of black hole growth and evolution, and of feeding and feedback. We have studied a sample of such objects, and find (1) that the locus of NLS1 galaxies on the MBH–σ plane appears to follow the relation of non-active galaxies after removing objects obviously dominated by outflows, (2) the presence of “blue outliers” that hint at extreme outflows as predicted by recent merger models, and (3) more subtle evidence for winds/outflows across the whole NLS1 population.


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