English
Related papers

Related papers: Difference of $\alpha$-disks between Seyfert 1 gal…

200 papers

We assume that the gravitational instability of standard thin accretion disks leads to the Broad Line Regions (BLRs), the B band luminosity comes from standard thin disk and the motion of BLRs is virial. The central black hole masses, the…

Astrophysics · Physics 2009-11-07 W. Bian , Y. Zhao

We used the standard geometrical thin accretion theory to obtain the accretion rates in Seyfert 1 galaxies and quasars. Combining accretion rates with the bolometric luminosity, we obtained the accretion efficiency. We found most of Seyfert…

Astrophysics · Physics 2019-04-03 Bian Weihao , Zhao Yongheng

The mass of the central black hole in Seyfert galaxies and QSOs can be determined from the broad emission lines and the reverberation method. Using the measured black hole mass and the bolometric or ionizing luminosity, the accretion rate…

Astrophysics · Physics 2009-10-31 Youjun Lu , Qingjuan Yu

We review the current status of the understanding how the accretion onto the central black hole proceeds in Active Galaxies. Standard accretion disk is a key element in all relatively bright active galaxies like Seyferts and quasars,…

High Energy Astrophysical Phenomena · Physics 2019-02-07 Bozena Czerny , Mohammad-Hassan Naddaf

In a matched sample of Seyfert and quiescent galaxies we simultaneously probe the stellar and molecular gas kinematics from 1 kpc down to 50 pc with the aim of identifying the dynamical processes dictating black hole accretion rates. This…

We use the difference (delta) between the position angles of the nuclear radio emission and the host galaxy major axis to investigate the distribution of the angle (beta) between the axes of the nuclear accretion disk and the host galaxy…

Astrophysics · Physics 2009-10-31 Neil M. Nagar , Andrew S. Wilson

We present a high density disc reflection spectral analysis of a sample of 17 Seyfert 1 galaxies to study the inner disc densities at different black hole mass scales and accretion rates. All the available XMM-Newton observations in the…

We analyze the broadband photometric light curves of Seyfert 1 galaxies from the Sergeev et al. (2005) sample and find that a) perturbations propagating across the continuum emitting region are a general phenomenon securely detected in most…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Doron Chelouche

We investigate the relationship between the present day optical luminosity function of galaxies and the X-ray luminosity function of Seyfert 1s to determine the fraction of galaxies which host Seyfert 1 nuclei and their Eddington ratios.…

Astrophysics · Physics 2009-11-07 M. J. Page

The spectra of quasars and NLS1 galaxies show surprising similarity in their spectral shape. They seem to scale only with the accretion rate. This is in contradiction with the simple expectations from the standard disk model which predicts…

Astrophysics · Physics 2009-11-10 B. Czerny , M. Nikolajuk , A. Rozanska , A. -M. Dumont , Z. Loska , P. T. Zycki

We present a comprehensive spectroscopic and variability-based characterisation of a sample of low-luminosity active galactic nuclei (AGNs) hosting low mass black holes, identified by $H\beta$ full width at half maximum (FWHM) $< 2200$ km…

Astrophysics of Galaxies · Physics 2025-12-09 Himanshu Sharma , Vivek Kumar Jha , Hum Chand , Swayamtrupta Panda

We analyze an X-ray flux-limited, complete sample of 93 AGN at z< 0.1, selected from the ROSAT Bright Survey. Two thirds of the sample are Seyfert 1 galaxies (Sy1) and one third are Narrow-Line Seyfert 1 galaxies (NLSy1). We have obtained…

Astrophysics · Physics 2009-11-10 M. Salvato , J. Greiner , B. Kuhlbrodt

We present evidence for widespread relativistic effects in the central regions of active galactic nuclei. In a sample of 18 Seyfert 1 galaxies observed by \asca, 14 show an iron K$\alpha$ line which is is resolved, with mean width…

Astrophysics · Physics 2009-10-28 K. Nandra , I. M. George , R. F. Mushotzky , T. J. Turner , T. Yaqoob

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 interaction of a supermassive black hole with the matter of an accretion disk in the presence of a magnetic field is the key mechanism of energy release in active galactic nuclei. However, determining the physical parameters of this…

High Energy Astrophysical Phenomena · Physics 2023-10-10 M. Yu. Piotrovich , E. S. Shablovinskaya , E. A. Malygin , S. D. Buliga , T. M. Natsvlishvili

Recent theoretical and observational works indicate the presence of a correlation between the star formation rate (SFR) and the active galactic nuclei (AGN) luminosity (and, therefore, the black hole accretion rate) of Seyfert galaxies.…

The spectrum of Seyfert 1 Galaxies is very similar to that of several Galactic Black Hole Candidates (GBHCs) in their hard state, suggestive that both classes of objects have similar physical processes. While it appears that an accretion…

Astrophysics · Physics 2007-05-23 Sergei Nayakshin , James B. Dove

We performed a comprehensive analysis of flux and color variability in a redshift-matched sample of Seyfert galaxies, comprising 23 gamma-ray-detected narrow-line Seyfert 1 galaxies (gNLS1s), 190 non-gamma-ray-detected narrow-line Seyfert 1…

High Energy Astrophysical Phenomena · Physics 2025-09-17 Vineet Ojha , Xue-Bing Wu , Luis C. Ho

We used narrowband interference filters with the CCD imaging camera on the Nickel 1.0 meter telescope at Lick Observatory to observe 31 nearby (z < 0.03) Seyfert galaxies in the 12 {\mu}m Active Galaxy Sample. We obtained pure emission line…

Astrophysics of Galaxies · Physics 2016-05-11 R. L. Theios , M. A. Malkan , N. R. Ross

The recent observations of highly accreting supermassive black holes (SMBH) at very high redshift ($>$4) with the James Webb Space Telescope (JWST) allowed us to shed light for the very first time on the early evolutionary phases of active…

Astrophysics of Galaxies · Physics 2025-09-05 M. Berton , E. Järvelä , A. Tortosa , C. Mazzucchelli
‹ Prev 1 2 3 10 Next ›