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相关论文: Complex Narrow Line Seyfert 1s: High spin or high …

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We report a detailed analysis of the XMM-Newton spectra of six Narrow-Line Seyfert 1 (NLS1) galaxies at redshift z = 0.35--0.92. Compared with the NLS1s at lower redshift in the previously most-studied sample, these NLS1s have larger black…

The emission and absorption attributes of the UV-blue nuclear spectra of the Narrow-Line Seyfert 1 (NLS1) galaxies are analyzed based on high quality archival HST observations. Measurements from composite spectra as well as from individual…

天体物理学 · 物理学 2007-05-23 Anca Constantin , Joseph C. Shields

We investigated narrow line Seyfert 1 galaxies (NLS1s) at optical, mid-infrared (MIR) and X-ray wavelengths, comparing them to the broad line active galactic nuclei (BLAGNs). We found that black hole mass, coronal line luminosities, X-ray…

星系天体物理 · 物理学 2018-05-23 Maša Lakićević , Luka Č. Popović , Jelena Kovačević-Dojčinović

Narrow line Seyfert 1 (NLSy1) galaxies constitute a class of active galactic nuclei characterized by the full width at half maximum (FWHM) of the H$\beta$ broad emission line < 2000 km/s and the flux ratio of [O III] to H$\beta$ < 3. Their…

星系天体物理 · 物理学 2017-06-06 Suvendu Rakshit , C. S. Stalin , Hum Chand , Xue-Guang Zhang

1H0323+342 is one of narrow-line radio-loud Seyfert 1 galaxies (RL-NLS1), which is a new class of gamma-ray emitting AGNs. Narrow-line Seyfert 1 galaxies (NLS1) have a small-mass black hole, but its mass accretion rate is almost as high as…

高能天体物理现象 · 物理学 2015-03-12 H. Shirakawa , Y. Fukazawa , Y. Tanaka , R. Itoh , K. Kawaguchi

Narrow-line Seyfert 1s (NLSy1s) are an ill-defined class. Work done over the past 20 years as well as recent analyses show a continuity in properties (e.g., Balmer line profiles, blueshifts of high-ionization lines) between sources with…

I briefly review the X/UV absorber models and show that the observations of NLS1s are generally consistent with the models. The covering factor of absorbers in NLS1s is likely to be high and there is some evidence of super-solar…

天体物理学 · 物理学 2009-10-31 Smita Mathur

We show that disc continuum fitting can be used to constrain black hole spin in a subclass of Narrow Line Seyfert 1 (NLS1) AGN as their low mass and high mass accretion rate means that the disc peaks at energies just below the soft X-ray…

高能天体物理现象 · 物理学 2015-06-16 Chris Done , C. Jin , M. Middleton , M. Ward

We present an analysis of spectrum and variability of the bright reddened narrow line Seyfert 1 galaxy Was~61 using 90 ks archival {\it XMM-Newton} data. The X-ray spectrum in 0.2-10 keV can be characterized by an absorbed power-law plus…

高能天体物理现象 · 物理学 2016-03-11 Liming Dou , Ting-Gui Wang , Yanli Ai , Weimin Yuan , Hongyan Zhou , Xiao-Bo Dong

We study properties of Fe K lines of a large sample of Seyfert 1s observed by ASCA. Fits with power laws and Gaussian lines yield the average linewidth and equivalent width of 0.22+-0.03 keV and 0.13+-0.01 keV, respectively. Thus, the…

天体物理学 · 物理学 2009-10-31 Piotr Lubinski , Andrzej Zdziarski

We have conducted a multiwavelength survey of 42 radio loud narrow-1ine Seyfert 1 galaxies (RLNLS1s), selected by searching among all the known sources of this type and omitting those with steep radio spectra. We analyse data from radio…

In recent years, several Radio-Loud Narrow-Line Seyfert 1 galaxies (RL-NLS1) possessing relativistic jets have come into attention with their detections in Very Large Baseline Array (VLBA) and in $\gamma$-ray observations. In this paper we…

星系天体物理 · 物理学 2018-07-09 Veeresh Singh , Hum Chand

Radio-loud Narrow-line Seyfert 1 (NLS1) galaxies are unique probes of the formation of powerful radio jets at extreme (near-Eddington) accretion rates and low black hole masses, in a regime very different from classical blazars and,…

星系天体物理 · 物理学 2018-08-07 S. Komossa

In this work, we test the hypothesis that narrow-line Seyfert 1 galaxies (NSL1s) are active galactic nuclei in their early phase and are therefore younger and more active than the more common broad-line Seyfert 1 galaxies (BLS1s). If that…

高能天体物理现象 · 物理学 2018-07-17 James K. Williams , Mario Gliozzi , Ross V. Rudzinsky

Narrow-line Seyfert 1 galaxies (NLS1) are active galactic nuclei (AGN) known to have small masses of the central black hole and high accretion rates. NLS1s are generally radio-quiet, but a small part of them (about 7\%) are radio-loud. The…

星系天体物理 · 物理学 2016-02-25 M. Berton , L. Foschini , A. Caccianiga , J. L. Richards , S. Ciroi , E. Congiu , V. Cracco , G. La Mura , L. Marafatto , P. Rafanelli

Using new XMM-Newton observations we detect hard X-ray time lags in the rapid variability of the Compton-thin Seyfert 2 galaxy IRAS 18325-5926. The higher-energy X-ray variations lag behind correlated lower-energy variations by up to ~3ks…

高能天体物理现象 · 物理学 2015-06-22 Andrew Lobban , William Alston , Simon Vaughan

The soft (\approx 0.1--2.0 keV) X-ray spectra of narrow-line Seyfert 1 galaxies are known to be generally steeper than those of Seyfert 1 galaxies with broader optical permitted lines. This has been attributed to the presence of strong soft…

天体物理学 · 物理学 2016-01-13 W. N. Brandt , S. Mathur , M. Elvis

Previous X-ray works on Mrk 1239 have revealed a complex Narrow Line Seyfert 1 (NLS1) that exhibits substantial absorption and strong emission from both collisional (CIE) and photoionized (PIE) plasmas. Here, we report on deep-pointed…

高能天体物理现象 · 物理学 2024-05-15 Margaret Z. Buhariwalla , L. C. Gallo , J. Mao , J. Jiang , L. K. Pothier-Bogoslowski , E. Järvelä , S. Komossa , D. Grupe

(abridged) I present and discuss the results of HST STIS observations of IRAS 13224-3809 and 1H 0707-495, two narrow-line Seyfert 1 (NLS1) galaxies. We discovered that high-ionization UV emission lines are much broader and strongly…

天体物理学 · 物理学 2007-05-23 Karen M. Leighly

(abridged) The soft excess seen in the X-ray spectra of many high mass accretion rate AGN can be well modelled by reflection from a partially ionised accretion disc. However, the derived parameters are often extreme, both in terms of the…

天体物理学 · 物理学 2009-11-13 M. J. Middleton , C. Done , M. Gierlinski