相关论文: The Baldwin Effect and Black Hole Accretion: A Spe…
Broad emission lines is a prominent property of type I quasi-stellar objects (QSOs). The origin of the Baldwin effect for \civ $\lambda1549~$\AA\ broad emission lines, i.e., the luminosity dependence of the \civ equivalent width (EW), is…
The origin of the luminosity dependence of the strength of broad and narrow emission lines in AGN (i.e. the Baldwin effect) is not firmly established yet. We explore this question using the Boroson & Green sample of the 87 z<=0.5 PG…
The spectrum of a quasar contains important information about its properties. Thus, it can be expected that two quasars with similar spectra will have similar properties, but just how similar has not before been quantified. Here we compare…
Accretion processes in quasars and active galactic nuclei are still poorly understood, especially as far as the connection between observed spectral properties and physical parameters is concerned. Quasars show an additional degree of…
We suggest that the Baldwin Effect is a result of the spectral dependence of the line-driving ionizing continuum on the black hole mass. We derive a relationship between the mass of the central black hole and the broad emission line…
From a large homogeneous sample of optical/UV emission line measurements for 993 quasars from the Large Bright Quasar Survey (LBQS), we study correlations between emission line equivalent width and both restframe ultraviolet luminosity…
The UV to soft X-rays of luminous AGNs dominate their bolometric luminosity, driven by an accretion-powered dynamo at the center. These photons ionize the surrounding gas, thereby providing clues to fueling and exhaust. Two sets of…
Using a large sample of quasar spectra from the SDSS, we examine the composite spectral trends of quasars as functions of both redshift and luminosity, independently of one another. Aside from the well known Baldwin effect (BE) -- the…
We present composite UV spectra for low redshift Type 1 AGN binned to exploit the information content of the Eigenvector 1 (E1) parameter space. Composite spectra allow a decomposition of the CIV1549 line profile - one of the strongest…
The well-known anti-correlation between the optical/ultraviolet (UV) emission line equivalent widths of active galactic nuclei and the continuum luminosity (the so-called Baldwin effect) is a long-standing puzzle. One common hypothesis is…
Quasar emission lines are sensitive to both the luminosity and shape of the quasars' high energy continuum - primarily in the soft X-ray and the (obscured) extreme ultraviolet. We initiate the first large-scale, multi-line investigation of…
Understanding the inverse equivalent width - luminosity relationship (Baldwin Effect), the topic of this meeting, requires extracting information on continuum and emission line parameters from samples of AGN. We wish to discover whether,…
Using 16,421 spectra from a sample of 340 quasars ($1.62<z<3.30$) from the SDSS Reverberation Mapping Project, we present an analysis of quasar spectral variability. We confirm the intrinsic Baldwin Effect and brighter-means-bluer trends in…
Using a large sample of 26623 quasars with redshifts in the range $1.5 \le z\le 5.1$ with \civ $\lambda$1549 \AA emission line in Fifth Data Release of the Sloan Digital Sky Survey (SDSS), we investigate the cosmological evolution of the…
We use UV/optical and X-ray observations of 272 radio-quiet Type 1 AGNs and quasars to investigate the CIV Baldwin Effect (BEff). The UV/optical spectra are drawn from the Hubble Space Telescope, International Ultraviolet Explorer and Sloan…
Quasars accretion models predict a broad range of optical and ultraviolet properties that depend primarily on black hole mass and accretion rate. Yet, most optically selected luminous quasars display strikingly similar continuum spectra. We…
The origin of the luminosity dependence of the equivalent width (EW) of broad emission lines in AGN (the Baldwin effect) is not firmly established yet. We explore this question for the broad C IV \lambda 1549 line using the Boroson & Green…
Using the properties of SDSS DR7 QSOs catalog from Shen et al., the Baldwin effect, its slope evolution, the underlying drive for a large sample of 35019 QSOs with reliable spectral analysis are investigated. We find that the Baldwin effect…
We contrast measurements of composite optical and ultraviolet (UV) spectra constructed from samples of QSOs defined by their soft X-ray brightness. X-ray bright (XB) composites show stronger emission lines in general, but particularly from…
After a short review of the quasar problem and what we can hope to learn from their emission line spectra, I discuss the current body of knowledge concerning quasar emission lines and their relationships to the local and ionizing continua.…