A Survey of<i>z</i> &gt; 5.7 Quasars in the Sloan Digital Sky Survey. IV. Discovery of Seven Additional Quasars

Fan, Xiaohui; Strauss, Michael A.; Richards, Gordon T.; Hennawi, Joseph F.; Becker, R. H.; White, R. L.; Diamond‐Stanic, Aleksandar M.; Donley, J. L.; Jiang, Linhua; Kim, J. Serena; Vestergaard, M.; Young, Jason; Gunn, James E.; Lupton, Robert H.; Knapp, G. R.; Schneider, Donald P.; Brandt, W. N.; Bahcall, Neta A.; Barentine, John C.; Brinkmann, J.; Brewington, H.; Fukugita, M.; Harvanek, Michael; Kleinman, S. J.; Krzesiński, Jurek; Long, D.; Neilsen, Eric H.; Nitta, A.; Snedden, Stephanie A.; Voges, W.

doi:10.1086/500296

Cited by 384 publications

(235 citation statements)

References 48 publications

(39 reference statements)

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“…More distant, high redshift galaxies (z<5) host a significant reservoir of dust, above 10 7 M (Bertoldi et al 2003;Carilli et al 2004;Fan et al 2006;Willott et al 2010). Recently, Zavala et al (2015) measured for the first time a dust mass of 10 7 M at redshift ∼ 9.…”

Section: Introductionmentioning

confidence: 99%

The cosmic dust rate across the Universe

Gioannini¹,

Matteuccí

Calura

2017

Monthly Notices of the Royal Astronomical Society

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We investigate the evolution of interstellar dust in the Universe by means of chemical evolution models of galaxies of different morphological types, reproducing the main observed features of present day galaxies. We adopt the most updated prescriptions for dust production from supernovae and asymptotic giant branch (AGB) stars as well as for dust accretion and destruction processes. Then, we study the cosmic dust rate in the framework of three different cosmological scenarios for galaxy formation: i) a pure luminosity scenario (PLE), ii) a number density evolution scenario (DE), as suggested by the classical hierarchical clustering scenario and iii) an alternative scenario, in which both spirals and ellipticals are allowed to evolve in number on an observationally motivated basis. Our results give predictions about the evolution of the dust content in different galaxies as well as the cosmic dust rate as a function of redshift. Concerning the cosmic dust rate, the best scenario is the alternative one, which predicts a peak at 2 < z < 3 and reproduces the cosmic star formation rate. We compute the evolution of the comoving dust density parameter Ω dust and find agreement with data for z < 0.5 in the framework of DE and alternative scenarios. Finally, the evolution of the average cosmic metallicity is presented and it shows a quite fast increase in each scenario, reaching the solar value at the present time, although most of the heavy elements are incorporated into solid grains, and therefore not observable in the gas phase.

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Section: Introductionmentioning

confidence: 99%

The cosmic dust rate across the Universe

Gioannini¹,

Matteuccí

Calura

2017

Monthly Notices of the Royal Astronomical Society

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“…According to our current understanding of the reionisation history of the Universe (Fan et al 2006;McQuinn et al 2009;Jarosik et al 2011;Haardt & Madau 2012), hydrogen was reionised by the ultraviolet radiation of the first stars and quasars, starting at z 10; with the increasing overlap of IGM H ii regions, hydrogen reionisation was completed around z 6 , leaving the IGM completely transparent to photons with hν > 13.6 eV. During the early stages of H i reionisation, the ionising radiation field was sufficiently hard to ionise He i (IP = 24.6 eV), but not He ii (IP = 54.4 eV).…”

Section: Introductionmentioning

confidence: 99%

The ESO UVES Advanced Data Products Quasar Sample – IV. On the deficiency of argon in DLA systems

Zafar¹,

Vladilo²,

Péroux³

et al. 2014

Monthly Notices of the Royal Astronomical Society

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In this work, we study argon abundances in the interstellar medium of high-redshift galaxies (2.0 z abs 4.2) detected as Damped Lyα absorbers (DLA) in the spectra of background quasars. We use high-resolution quasar spectra obtained from the ESO-UVES advanced data products (EUADP) database. We present 3 new measurements and 5 upper limits of Ar i. We further compiled DLAs/sub-DLA data from the literature with measurements available of argon and α-capture elements (S or Si), making up a total of 37 systems, i.e. the largest DLA argon sample investigated so far. We confirm that argon is generally deficient in DLAs, with a mean value [Ar/α] ≃ −0.4 ± 0.06 dex (standard error of the mean). The [Ar/α] ratios show a weak, positive trend with increasing H i column density and increasing absorption redshift, and a weak, negative trend with dust-free metallicity, [S/H]. Detailed analysis of the abundance ratios indicates that Ar i ionisation, rather than dust depletion or nucleosynthetic evolution, is responsible for the argon deficiency. Altogether, the observational evidence is consistent with a scenario of argon ionisation dominated by quasar metagalactic radiation modulated by local H i self-shielding inside the DLA host galaxies. Our measurements and limits of argon abundances suggest that the cosmic reionisation of He ii is completed above z ∼ 3, but more measurements at z abs > 3.5 are required to probe the final stages of this process of cosmic reionisation.

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“…Quinlan & Shapiro 1990;Devecchi & Volonteri 2009;Davies, Miller & Bellovary 2011;Devecchi et al 2012;Lupi et al 2014). Both proposals, however, face difficulties in explaining the few observational constraints available, namely the early occurrence of massive ( 10 9 − 10 10 M ⊙ ) accreting black holes in z ∼ 6 − 7 quasars (Fan et al 2006;Mortlock et al 2011; but see also Treister et al 2013). The main reason is that both scenarios tend to predict ⋆ E-mail: fiacconi@physik.uzh.ch † E-mail: emr@strw.leidenuniv.nl small seeds (up to ∼ 1000 M ⊙ at most) which are unlikely to grow fast enough to power those high-z quasars, unless sustained super-Eddington accretion is advocated (e.g.…”

Section: Introductionmentioning

confidence: 99%

Bright vigorous winds as signposts of supermassive black hole birth

Fiacconi

Rossi

2015

Mon. Not. R. Astron. Soc.

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The formation of supermassive black holes is still an outstanding question. In the quasi-star scenario, black hole seeds experience an initial super-Eddington growth, that in less than a million years may leave a 10 4 − 10 5 M ⊙ black hole at the centre of a protogalaxy at z ∼ 20 − 10. Super-Eddington accretion, however, may be accompanied by vigorous mass loss that can limit the amount of mass that reaches the black hole. In this paper, we critically assess the impact of radiative driven winds, launched from the surface of the massive envelopes from which the black hole accretes. Solving the full wind equations coupled with the hydrostatic structure of the envelope, we find mass outflows with rates between a few tens and 10 4 M ⊙ yr −1 , mainly powered by advection luminosity within the outflow. We therefore confirm the claim by Dotan, Rossi & Shaviv (2011) that mass losses can severely affect the black hole seed early growth within a quasi-star. In particular, seeds with mass > 10 4 M ⊙ can only form within mass reservoirs 10 7 M ⊙ , unless they are refilled at huge rates ( 100 M ⊙ yr −1 ). This may imply that only very massive halos (> 10 9 M ⊙ ) at those redshifts can harbour massive seeds. Contrary to previous claims, these winds are expected to be relatively bright (10 44 − 10 47 erg s −1 ), blue (T eff ∼ 8000 K) objects, that while eluding the Hubble Space Telescope, could be observed by the James Webb Space Telescope.

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A Survey ofz > 5.7 Quasars in the Sloan Digital Sky Survey. IV. Discovery of Seven Additional Quasars

Cited by 384 publications

References 48 publications

The cosmic dust rate across the Universe

The cosmic dust rate across the Universe

The ESO UVES Advanced Data Products Quasar Sample – IV. On the deficiency of argon in DLA systems

Bright vigorous winds as signposts of supermassive black hole birth

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