相关论文: Dissecting the quasar main sequence: insight from …
The dependence of the long-term optical/UV variability on the spectral and the fundamental physical parameters for radio-quiet active galactic nuclei (AGNs) is investigated. The multi-epoch repeated photometric scanning data in the…
The velocities of the [O III] 5007 and optical Fe II emission lines, measured relative to the systemic redshifts of 2265 QSOs by Hu et al. (2008), show the signature of a disklike BLR structure with polar outflows. Objects with large [O…
By means of the data sets of the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS), we investigate the relationship between the variability amplitude and luminosity at 5100 \AA, black hole mass, Eddington ratio, $ R_{\rm Fe…
We present the redshift evolution of quasar luminosity functions decomposed by halo mass, galaxy mass, supermassive black hole (SMBH) mass, and Eddington ratio, as well as SMBH kinetic/radiative energy output ratios from TRINITY, a flexible…
We study the dependence of the number density and properties of quasars on the background galaxy density using the currently largest spectroscopic datasets of quasars and galaxies. We construct a galaxy number density field smoothed over…
We present new near-infrared (IR) observations of the H$\beta\ \lambda4861$ and MgII $\lambda2798$ lines for 32 luminous quasars with $3.2<z<3.9$ using the Palomar Hale 200 inch telescope and the Large Binocular Telescope. We find that the…
We compare the host galaxies properties of BL Lac objects with those of radio loud quasars (RLQs) imaged by the WFPC2 on board of HST. The considered objects (z<0.5) are always well resolved and their host galaxies satisfactorily modelled…
We derive black hole masses for a sample of about 300 AGNs in the redshift range 0 < z < 2.5. We use the same virial velocity measure (FWHM Hbeta broad component) for all sources which represents a significant improvement over previous…
Growth of massive black holes (MBHs) in galactic centers comes mainly from gas accretion during their QSO/AGN phases. In this paper we apply an extended Soltan argument, connecting the local MBH mass function with the time-integral of the…
The relation between star formation rates and stellar masses, i.e. the galaxy main sequence, is a useful diagnostic of galaxy evolution. We present the distributions relative to the main sequence of 55 optically-selected PG and 12…
We present the discovery of a large gradual apparent fading event in optical and near-infrared wavelengths in a quasar at z=1.767 by a factor of 20-30 (in optical) over a period of ~20 years in the observed frame. This pronounced fading…
We have assembled a sample of 37 RLQs that have been imaged with the HST in order to investigate their black hole masses, accretion rates, and the structure of their accretion disks. The black hole masses were estimated from the…
We examine the accretion properties in a sample of 42 hard (3-60keV) X-ray selected nearby broad-line AGNs. The energy range in the sample is harder than that usually used in the similar previous studies. These AGNs are mainly complied from…
QSOs allow study of the evolution of the relationship between black holes in galactic nuclei and their host galaxies. The black hole mass can be derived from the widths of the broad emission lines, and the stellar velocity dispersion…
We examine how much information measured broad-line widths add to virial BH mass estimates for flux limited samples of quasars. We do this by comparing the BH mass estimates to those derived by randomly reassigning the quasar broad-line…
Quasars accreting at very high rates are believed to be prime movers of galactic evolution because of their high radiative and mechanical output. The study presented in this paper investigates a sample of six highly accreting quasars at…
Supermassive black holes (BHs) and their host galaxies are interlinked by virtue of feedbacks and are thought to be co-eval across the Hubble time. This relation is highlighted by an approximate proportionality between the BH mass…
We have investigated a sample of 5088 quasars from the Sloan Digital Sky Survey Second Data Release in order to determine how the frequency and properties of broad absorptions lines (BALs) depend on black hole mass, bolometric luminosity,…
Although flux variability is one of the defining properties of accretion flows onto supermassive black holes, its dependence on physical parameters such as the mass of the compact object and the Eddington ratio remain under discussion. In…
Recent studies of black holes in the nuclei of both active and normal galaxies have yielded relationships that permit a physical interpretation of the principal components of the spectra of QSOs. It is shown that principal component (or…