Estimating the effective lifetime of the $z\sim 6$ quasar population from the composite proximity zone profile

Abstract

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 intergalactic gas has a finite response time to the quasars' radiation. We estimate the effective lifetime of the high-redshift quasar population from the composite transmitted flux profile within the proximity zone region of a sample of $15$ quasars at $5.8\le z\le 6.6$ with precise systemic redshifts, and similar luminosities, i.e. $-27.6\le M_{1450}\le -26.4$, and thus a similar instantaneous ionizing power. We develop a Bayesian method to infer the effective lifetime from the composite spectrum, including robust estimates of various sources of uncertainty on the spectrum. We estimate an effective lifetime of the quasar population as a whole of ${\log }_{10}(t_Q/yr)=5.7_{-0.3(-0.5)}^{+0.5(+0.8)}$ given by the median and $68$th ($95$th) percentile of the posterior probability distribution. While our result is consistent with previous quasar lifetime studies, it poses significant challenges on the current model for the growth of supermassive black holes (SMBHs) located in the center of the quasars' host galaxies, which requires that quasar lifetimes are more than an order of magnitude longer.

15 pages, 7 figures, accepted by ApJ

References in corpus (20)

• A luminous quasar at a redshift of z = 7.085
• An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
• Supermassive black hole formation during the assembly of pre-galactic discs
• Pōniuā'ena: A Luminous $z=7.5$ Quasar Hosting a 1.5 Billion Solar Mass Black Hole
• Physical properties of 15 quasars at $z\gtrsim 6.5$
• The first ultraviolet quasar stacked spectrum at z=2.4 from WFC3
• A Significantly Neutral Intergalactic Medium Around the Luminous z=7 Quasar J0252-0503
• Correcting for Telluric Absorption: Methods, Case Studies, and Release of the TelFit Code
• Quasars Probing Quasars II: The Anisotropic Clustering of Optically Thick Absorbers around Quasars
• Quasar Proximity Zones and Patchy Reionization
• Direct collapse black hole formation from synchronized pairs of atomic cooling halos
• The formation of direct collapse black holes under the influence of streaming velocities
• Hot Gaseous Coronae around Spiral Galaxies: Probing the Illustris Simulation
• Constraints on the correlation between QSO luminosity and host halo mass from high-redshift quasar clustering
• On the Accretion Rates and Radiative Efficiencies of the Highest Redshift Quasars
• Detecting and Characterizing Young Quasars II: Four Quasars at $z\sim 6$ with Lifetimes $<10^4$ years
• A comparison of quasar emission reconstruction techniques for $z\ge 5.0$ Lyman-$\alpha$ and Lyman-$\beta$ transmission
• The first measurement of the quasar lifetime distribution
• A closer look at using quasar near-zones as a probe of neutral hydrogen in the intergalactic medium
• Dating individual quasars with the HeII proximity effect

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• Chronicling the reionization history at $6\lesssim z\lesssim 7$ with emergent quasar damping wings
• EIGER III. JWST/NIRCam observations of the ultra-luminous high-redshift quasar J0100+2802
• First results from the JWST Early Release Science Program Q3D: The Warm Ionized Gas Outflow in z ~ 1.6 Quasar XID 2028 and its Impact on the Host Galaxy
• The need for obscured supermassive black hole growth to explain quasar proximity zones in the epoch of reionization
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• A Generative Model for Quasar Spectra
• Probing quasar lifetimes with proximate $21$-centimetre absorption in the diffuse intergalactic medium at redshifts $z\ge 6$
• Prospects for Observing High-redshift Radio-loud Quasars in the SKA Era: Paving the Way for 21-cm Forest Observations
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• A comparison of numerical methods for computing the reionization of intergalacitc hydrogen and helium by a central radiating source
• Quasar lifetime measurements from extended Ly$\alpha$ nebulae at $z\sim 6$
• A unique window into the Epoch of Reionisation: A double-peaked Lyman-$\alpha$ emitter in the proximity zone of a quasar at $z\sim 6.6$
• A first look at quasar-galaxy clustering at $z\simeq 7.3$
• A local, topology-independent parameterization of quasar IGM damping wings
• First constraints on the local ionization topology in front of two quasars at z ~ 7.5
• A Simple Condition for Sustained Super-Eddington Black Hole Growth
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