相关论文: Constraining the Lifetime of Quasars from their Sp…
Although the population of luminous quasars rises and falls over a period of 10^9 years, the typical lifetime of individual quasars is uncertain by several orders of magnitude. We show that quasar clustering measurements can substantially…
The lifetime of quasars can be estimated by means of their proximity zone sizes, which are regions of enhanced flux bluewards of the Lyman-$\alpha$ emission line observed in the rest-frame UV spectra of high-redshift quasars, because the…
We present a new method to measure the episodic lifetime of quasars with current and future large-scale sky surveys. Future photometric observations of large samples of confirmed quasars can provide a direct measurement (or interesting…
The existence of billion-solar-mass black holes hosted in luminous quasars within the first gigayear of cosmic history poses a challenge to our understanding of supermassive black hole (SMBH) growth. The problem is further exacerbated by…
The observed number counts of quasars may be explained either by long-lived activity within rare massive hosts, or by short-lived activity within smaller, more common hosts. It has been argued that quasar lifetimes may therefore be inferred…
The extents of proximity zones of high-redshift quasars enable constraints on the timescales of quasar activity, which are fundamental for understanding the growth of the supermassive black holes (SMBHs) that power the quasars' emission. In…
We consider implications of our new model of quasar lifetimes and light curves for the quasar luminosity function (LF) at different frequencies and redshifts. In our picture, quasars evolve rapidly and the lifetime depends on both their…
Recently, a very large clustering length has been measured for quasars at a redshift of z~4. In combination with the observed quasar luminosity function we assess the implications of this clustering for the relationship between quasar…
We present detailed clustering measurements from the 2dF QSO Redshift Survey (2QZ) in the redshift range 0.8<z<2.1. Using a flux limited sample of ~14,000 objects with effective redshift z_eff=1.47, we estimate the quasar projected…
We constrain the average episodic quasar lifetime (as in steady-state accretion) using two statistics of quasars that are recently turned off (i.e., dimmed by a large factor): 1) the fraction of turned-off quasars in a statistical sample…
Understanding the growth of the supermassive black holes powering luminous quasars, their co-evolution with host galaxies, and impact on the surrounding intergalactic medium depends sensitively on the duration of quasar accretion episodes.…
We study the cross-correlation between quasars and galaxies by embedding models for the formation and evolution of the two populations in cosmological N-body simulations. We adopt the quasar evolution model of Kauffmann & Haehnelt (2000),…
We present detailed clustering measurements for a flux limited sample of 14,000 quasars extracted from the 2dF QSO Redshift Survey (2QZ) in the redshift range 0.8<z<2.1. After splitting the sample into three redshift bins and each of them…
We propose a model of quasar lifetimes in which observational quasar lifetimes and an intrinsic lifetime of rapid accretion are strongly distinguished by the physics of obscuration by surrounding gas and dust. Quasars are powered by gas…
We propose a new interpretation of the quasar luminosity function (LF), derived from physically motivated models of quasar lifetimes and light curves. In our picture, quasars evolve rapidly and their lifetime depends on both their…
The QSO lifetime t_Q is one of the most fundamental quantities for understanding black hole and QSO evolution, yet it remains uncertain by several orders of magnitude. If t_Q is long, then only a small fraction of galaxies went through a…
Recent observations from the EIGER JWST program have measured for the first time the quasar-galaxy cross-correlation function at $z\approx6$. The auto-correlation function of faint $z\approx6$ quasars was also recently estimated. These…
We investigate the spatial clustering of galaxies around quasars at redshifts from 0.6 to 1.2 using the photometric data from Sloan Digital Sky Survey (SDSS) Stripe 82. The quasar and galaxy cross-correlation functions are measured through…
We investigate the luminosity dependence of quasar clustering, inspired by numerical simulations of galaxy mergers that incorporate black hole growth. These simulations have motivated a new interpretation of the quasar luminosity function.…
(Abridged) We study the two-point correlation function of a uniformly selected sample of 4,426 luminous optical quasars with redshift $2.9 \le z\le 5.4$ selected over 4041 deg$^2$ from the Fifth Data Release of the Sloan Digital Sky Survey.…