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Related papers: The Luminosity function of Narrow-Line Seyfert gal…

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We study the narrow-line region (NLR) of six Seyfert-1 and six Seyfert-2 galaxies by means of spatially resolved optical spectroscopy and photoionization modelling. From spatially resolved spectral diagnostics, we find a transition between…

Astrophysics · Physics 2007-05-23 Nicola Bennert , Bruno Jungwiert , Stefanie Komossa , Martin Haas , Rolf Chini , ;

We report here our comparative analysis of active galactic nucleus (AGN) and star formation (SF) characteristics of a sample of narrow-line Seyfert 1 (NLS1) and broad-line Seyfert 1 (BLS1) galaxies. Our sample consisted of 373 BLS1 and 240…

Astrophysics of Galaxies · Physics 2024-06-18 Kshama S. Kurian , C. S. Stalin , S. Rakshit , G. Mountrichas , D. Wylezalek , R. Sagar , M. Kissler-Patig

We present a detailed study of 11 narrow-line Seyfert 1 galaxies (NLS1s) from the Six-degree Field Galaxy Survey (6dFGS) that both have optical and X-ray spectroscopic observations. There are five complex NLS1s (C-NLS1s) and six simple…

Astrophysics of Galaxies · Physics 2019-10-01 S. Chen , G. La Mura , M. Berton , L. Foschini , E. Congiu , F. Di Mille , S. Ciroi , E. Bottacini , J. H. Fan , A. Vietri

Narrow-Line Seyfert 1s (NLS1s) are generally considered to be strange Active Galactic Nuclei (AGNs). Surprisingly, this makes them very useful for constraining models. I discuss what happens when one attempts to qualitatively fit the NLS1…

Astrophysics · Physics 2009-10-31 Jason A. Taylor

We present results from the analysis of the optical spectra of 47 radio-selected narrow-line Seyfert 1 galaxies (NLS1s). These objects are a subset of the First Bright Quasar Survey (FBQS) and were initially detected at 20 cm (flux density…

Astrophysics · Physics 2008-11-26 D. J. Whalen , S. A. Laurent-Muehleisen , E. C. Moran , R. H. Becker

We present the color and flux variability analysis at 3.4 {\mu}m (W1-band) and 4.6 {\mu}m (W 2-band) of 492 narrow-line Seyfert 1 (NLSy1) galaxies using archival data from the Wide-field Infrared Survey Explorer (WISE). In the WISE…

Astrophysics of Galaxies · Physics 2018-12-12 Suvendu Rakshit , Ansu Johnson , C. S. Stalin , Poshak Gandhi , Sebastian Hoenig

Here we describe the \emph{Siding Spring Southern Seyfert Spectroscopic Snapshot Survey} (S7) and present results on 64 galaxies drawn from the first data release. The S7 uses the Wide Field Spectrograph (WiFeS) mounted on the ANU 2.3m…

In a sample of 476931 NELGs obtained from the SDSS DR5 data we find that in 22% of the galaxies the emission line [OIII]$\lambda$5007, H$\beta$, or both, are missing. The nature of the activity in these galaxies was determined using a…

Astrophysics of Galaxies · Physics 2010-11-23 J. P. Torres-Papaqui , R. Coziol , J. M. Islas-Islas , R. A. Ortega-Minakata , D. M. Neri-Larios

X-ray luminosity functions (XLFs) of Active Galactic Nuclei (AGN) trace the growth and evolution of supermassive black hole populations across cosmic time, however, current XLF models are poorly constrained at redshifts of z>6, with a lack…

High Energy Astrophysical Phenomena · Physics 2023-01-25 Cassandra L. Barlow-Hall , Jack Delaney , James Aird , Philip A. Evans , Julian P. Osborne , Michael G. Watson

This paper presents a quantification of the X-ray variability amplitude for 79 ASCA observations of 36 Seyfert 1 galaxies. We find that consideration of sources with the narrowest permitted lines in the optical band introduces scatter into…

Astrophysics · Physics 2009-10-31 T. J. Turner , I. M. George , K. Nandra , D. Turcan

The last decade has witnessed a steadily increasing number of observational studies concerning the rare class of radio loud narrow-line Seyfert 1 galaxies, of which several hundred are currently known. According to the current AGN paradigm,…

Astrophysics of Galaxies · Physics 2018-05-15 Matthew L. Lister

We present the results of a detailed multi-wavelength study of a sample of sixteen narrow-line Seyfert 1 (NLSy1) galaxies known in $\gamma$-rays so far. This includes a focused X-ray spectral analysis, to compare them with a more general…

High Energy Astrophysical Phenomena · Physics 2019-02-27 Vaidehi S. Paliya , M. L. Parker , J. Jiang , A. C. Fabian , L. Brenneman , M. Ajello , D. Hartmann

We have examined ROSAT soft X-ray observations of a complete, distance-limited sample of Seyfert and LINER galaxies. X-ray data are available for 46 out of 60 such objects which lie within a hemisphere of radius 18 Mpc. We have constructed…

Astrophysics · Physics 2009-11-06 Eve L. Halderson , Edward C. Moran , Alexei V. Filippenko , Luis C. Ho

We have compiled a list of 83 objects classified as Narrow-Line Seyfert 1 galaxies (NLS1s) or known to have a broad Balmer component narrower than 2000 km/s. Out of these, 19 turned out to have been spectroscopically misidentified in…

Astrophysics · Physics 2009-11-06 M. -P. Veron-Cetty , P. Veron , A. C. Goncalves

ASCA observations of Narrow-Line Seyfert 1 galaxies (NLS1s) are presented. We focus on the black hole size of the NLS1 sources by employing two independent methods for the mass estimation; one is using X-ray variability, the other is using…

Astrophysics · Physics 2009-10-31 K. Hayashida

Narrow Line Seyfert 1 galaxies (NLS1s) are intriguing due to their continuum as well as emission line properties. The observed peculiar properties of the NLS1s are believed to be due to accretion rate close to Eddington limit. As a…

Astrophysics · Physics 2016-08-30 Smita Mathur

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…

Astrophysics of Galaxies · Physics 2018-07-09 Veeresh Singh , Hum Chand

We present a new accurate sample of narrow-line Seyfert 1 galaxies (NLS1s) in the southern hemisphere from the Six-degree Field Galaxy Survey (6dFGS). Based on the optical spectral features, 167 sources were classified as NLS1s. We derived…

Astrophysics of Galaxies · Physics 2018-09-19 S. Chen , M. Berton , G. La Mura , E. Congiu , V. Cracco , L. Foschini , J. H. Fan , S. Ciroi , P. Rafanelli , D. Bastieri

Narrow-line Seyfert 1 (NLS1) galaxies are a type of active galactic nuclei (AGN) that were originally classified as sources with little to no radio emission. Although the class is rather unified from an optical perspective, their radio…

Astrophysics of Galaxies · Physics 2025-11-26 I. Varglund , E. Järvelä , M. J. Hardcastle , S. Varglund , A. Lähteenmäki

We present the first measurement of the galaxy luminosity function at 1500A between 0.2<z<1.2 based on GALEX-VVDS observations (1000 spectroscopic redshifts for galaxies with NUV<24.5) and at higher z using existing datasets. Our main…

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