Imprints of the super-Eddington accretion on the quasar clustering

Oogi, Taira; Enoki, Motohiro; Ishiyama, Tomoaki; Kobayashi, Masakazu A. R.; Makiya, Ryu; Nagashima, Masahiro; Okamoto, Takashi; Shirakata, Hikari

doi:10.1093/mnrasl/slx102

Cited by 8 publications

(5 citation statements)

References 46 publications

(55 reference statements)

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“…∼ 10 8 − 10 9 yr (Volonteri 2010(Volonteri , 2012. Hence, under the assumption of a light-bulb light curve we have to invoke very massive initial seeds (M seed ∼ 10 9 M ), for which there is currently no theoretical foundation nor any potential progenitor objects known, or significantly super-Eddington accretion rates (Du et al 2015;Oogi However, there are several potential scenarios that could explain our findings. One option would be that the quasar has been growing for a much longer time than its lifetime estimate derived from the size of its proximity zone suggests, but it has been growing in a highly obscured phase, such that its ultraviolet (UV) radiation (and hence the ionizing continuum) has only "broken out" of this obscuring medium ∼ 10 4 yr ago (e.g.…”

Section: Summary and Discussionmentioning

confidence: 86%

First Spectroscopic Study of a Young Quasar

Eilers

Hennawi

Davies

2018

ApJ

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The quasar lifetime t Q is one of the most fundamental quantities for understanding quasar evolution and the growth of supermassive black holes (SMBHs), but remains uncertain by several orders of magnitude. In a recent study we uncovered a population of very young quasars (t Q 10 4 − 10 5 yr), based on the sizes of their proximity zones, which are regions of enhanced Lyα forest transmission near the quasar resulting from its own ionizing radiation. The presence of such young objects poses significant challenges to models of SMBH formation, which already struggle to explain the existence of SMBHs (∼ 10 9 M ) at such early cosmic epochs. We conduct the first comprehensive spectroscopic study of the youngest quasar known, SDSS J1335 + 3533 at z = 5.9012, whose lifetime is t Q < 10 4 yr (95% confidence). A careful search of our deep optical and near-infrared spectra for H I and metal absorption lines allows us to convincingly exclude the possibility that its small proximity zone results from an associated absorption system rather than a short lifetime. We use the Mg II emission line to measure the mass of its black hole to be M BH = (4.09 ± 0.58) × 10 9 M , implying an Eddington ratio of 0.30 ± 0.04 -comparable to other co-eval quasars of similar luminosity. We similarly find that the relationship between its black hole mass and dynamical mass are consistent with the scaling relations measured from other z ∼ 6 quasars. The only possible anomaly associated with SDSS J1335 + 3533's youth are its weak emission lines, but larger samples are needed to shed light on a potential causality. We discuss the implications of short lifetimes for various SMBH growth and formation scenarios, and argue that future observations of young quasars with JWST could distinguish between them. swered question in studies of black hole and galaxy evolution.It has been argued that in order to grow the observed masses of SMBHs this early, very massive initial seeds are required, and, assuming accretion at the Eddington limit, that accretion must occur continuously for the entire age of the universe (Volonteri 2010(Volonteri , 2012. These general considerations imply that the quasar lifetimethe total integrated time that galaxies shine as quasars -must be of the order of the Hubble time.However, measurements of quasar lifetimes have proven to be extremely challenging. At low redshifts, i.e. z ∼ 2 − 4, quasar lifetimes can be constrained by comparing the number density of quasars to their host dark matter halo abundance inferred from clustering studies arXiv:1806.05691v1 [astro-ph.GA]

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Section: Summary and Discussionmentioning

confidence: 86%

First Spectroscopic Study of a Young Quasar

Eilers

Hennawi

Davies

2018

ApJ

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“…This model originates from Nagashima & Yoshii (2004) and Nagashima et al (2005) (νGC model). Both νGC and ν 2 GC models have been used for a variety of astrophysical studies including gravitational waves, Lyα emitters, star formation, and AGN clustering (Enoki et al 2003;Enoki & Nagashima 2007;Kobayashi et al 2007;Makiya et al 2014;Oogi et al 2016Oogi et al , 2017. The SMBH growth and AGN properties in M16 are based on Enoki et al (2003), Enoki et al (2014), andShirakata et al (2015).…”

Section: Model Descriptionsmentioning

confidence: 99%

“…Volonteri & Natarajan 2009;Shirakata et al 2016), and AGN clustering (e.g. Fanidakis et al 2013;Oogi et al 2016Oogi et al , 2017.…”

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confidence: 99%

The New Numerical Galaxy Catalogue (ν2GC): properties of active galactic nuclei and their host galaxies

Shirakata

Okamoto

Kawaguchi

et al. 2018

Monthly Notices of the Royal Astronomical Society

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We present the latest results of a semi-analytic galaxy formation model, "New Numerical Galaxy Catalogue", which utilises large cosmological N-body simulations. This model can reproduce many statistical properties of galaxies at z 6. We focus on the properties of active galactic nuclei (AGNs) and supermassive black holes, especially on the accretion timescale onto black holes. We find that the number density of AGNs at z < 1.5 and at hard X-ray luminosity < 10 44 erg/s is underestimated compared with recent observational estimates when we assume the exponentially decreasing accretion rate and the accretion timescale which is proportional to the dynamical time of the host halo or the bulge, as is often assumed in semi-analytic models. We show that to solve this discrepancy, the accretion timescale of such less luminous AGNs should be a function of the black hole mass and the accreted gas mass. This timescale can be obtained from a phenomenological modelling of the gas angular momentum loss in the circumnuclear torus and/or the accretion disc. Such models predict a longer accretion timescale for less luminous AGNs at z < 1.0 than luminous QSOs whose accretion timescale would be 10 7−8 yr. With this newly introduced accretion timescale, our model can explain the observed luminosity functions of AGNs at z < 6.0.

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“…Abramowicz et al 1988;Watarai et al 2000;Mineshige et al 2000). Oogi et al (2017) have found that this limitation of the bolometric luminosity has a large impact on the clustering signal of the resultant mock AGN population. To include this effect, we adopt the following relation as the bolometric luminosity normalised by the Eddington luminosity, λ Edd ≡ L bol /L Edd :…”

Section: Agn Activitymentioning

confidence: 99%

Semi-analytic modelling of AGNs: auto-correlation function and halo occupation

Oogi,

Shirakata,

Nagashima

et al. 2019

Preprint

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The spatial clustering of active galactic nuclei (AGNs) is considered to be one of the important diagnostics for the understanding of the underlying processes behind their activities complementary to their abundance. We analyse the AGN clustering from a recent semi-analytic model performed on a large cosmological N -body simulation covering a cubic gigaparsec comoving volume. The recipe for the model has previously been shown to reproduce the observed luminosity function of AGN quite well over a wide redshift range (z < ∼ 6), with a newly introduced timescale to account for the loss of the angular momentum on small scales in the accretion process on to the supermassive black holes. The large simulation box allows us accurate determination of the auto-correlation function of the AGNs. The model prediction indicates that this timescale plays a significant role in allowing massive halos to host relatively faint population of AGNs, leading to a higher bias factor for those AGNs. The model predictions are in agreement with observations of X-ray selected AGNs in the luminosity range 10 41.5 erg s −1 ≤ L 2-10keV ≤ 10 44.5 erg s −1 , with the typical host halo mass of 10 12.5−13.5 h −1 M ⊙ at z < ∼ 1. Moreover, we find that not only the effective halo mass corresponding to the overall bias factor, but the extended shape of the predicted AGN correlation function shows remarkable agreement with those from observations. Further observational efforts in the near future towards the low luminosity end at redshift ∼ 1 would give us stronger constraints on the triggering mechanisms of AGN activities through the clustering properties.

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Imprints of the super-Eddington accretion on the quasar clustering

Cited by 8 publications

References 46 publications

First Spectroscopic Study of a Young Quasar

First Spectroscopic Study of a Young Quasar

The New Numerical Galaxy Catalogue (ν2GC): properties of active galactic nuclei and their host galaxies

Semi-analytic modelling of AGNs: auto-correlation function and halo occupation

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