Iron Emission in
                    <i>z</i>
                    6 QSO
                    <scp>s</scp>

Freudling, W.; Corbin, Michael R.; Korista, K. T.

doi:10.1086/375338

Cited by 109 publications

(142 citation statements)

References 31 publications

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“…We set the lower limit for the metallicity at the solar value and the upper limit at 5 Z . This is based on the inferred solar or supersolar metallicities in high-z QSOs (e.g., Barth et al 2003;Dietrich et al 2003;Fan et al 2003;Freudling et al 2003;Maiolino et al 2003;Di Matteo et al 2004;Becker et al 2006;Juarez et al 2009). We note that there are no strong constraints on the upper limit and therefore the zone above 5 Z is marked as light grey shaded region to account for the uncertainty.…”

Section: Metallicity and Sfrmentioning

confidence: 99%

“…Wang et al (2010) derived SFRs between 530-2300 M yr −1 from observations of a sample of QSOs at redshift z > 5. Observations of strong metal emission of high-z QSOs (e.g., Barth et al 2003;Dietrich et al 2003;Maiolino et al 2003;Becker et al 2006) indicate strong star forming activity in the QSO hosts and solar or supersolar metallicity (e.g., Fan et al 2003;Freudling et al 2003;Juarez et al 2009). Theoretical studies of the gas metallicity of QSO hosts also predict supersolar metallicities for z = 5-6 QSOs (e.g., Di Matteo et al 2004).…”

Section: Introductionmentioning

confidence: 99%

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Genesis and evolution of dust in galaxies in the early Universe

Gall

Andersen

Hjorth

2011

A&A

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Aims. We intend to assess the most plausible scenarios for generating large amounts of dust in high-z quasars (QSOs) on the basis of observationally derived physical properties of QSOs at z 6. Methods. We use a chemical evolution model to compute the temporal progression of quantities such as the amount of dust and gas, stellar masses, star formation rates (SFRs) and the metallicity for various combinations of the initial mass function (IMF), the mass of the galaxy, dust production efficiencies, and the degree of dust destruction in the ISM. We investigate the influence of the SFR on the evolution of these quantities, and determine the earliest epochs at which agreement with observations can be achieved. We apply the obtained results to individual QSOs at z 6. Results. We find that large quantities of dust can be generated rapidly as early as 30 Myr after the onset of the starburst when the SFR of the starburst is 10 3 M yr −1 . The amount of dust and several other physical quantities of individual QSOs at z 6 are satisfactorily reproduced by models at epochs 30, 70, 100, and 170 Myr for galaxies with initial gas masses of 1-3 × 10 11 M . The best agreement with observations is obtained with top-heavy IMFs. A sizable dust contribution from supernovae (SNe) is however required, while at these epochs dust production by asymptotic giant branch (AGB) stars is negligible. Moderate dust destruction in the ISM can be accommodated.

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Section: Metallicity and Sfrmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Genesis and evolution of dust in galaxies in the early Universe

Gall

Andersen

Hjorth

2011

A&A

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“…Many attempts have been made during last several decades to measure Fe ii (UV)/Mg ii ratios in QSOs and connect them with corresponding abundances (e.g., Kwan & Krolik 1981;Iwamuro et al 2002Iwamuro et al , 2003Iwamuro et al , 2004Freudling et al 2003). Two major techniques for subtracting or estimating the Fe ii emission spectra exist.…”

Section: Introductionmentioning

confidence: 99%

Modeling FeiiEmission and Revised Feii(UV) Empirical Templates for the Seyfert 1 Galaxy I Zw 1

Bruhweiler

Verner

2008

ApJ

123

173

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We use the narrow-lined broad-line region ( BLR) of the Seyfert 1 galaxy, I Zw 1, as a laboratory for modeling the ultraviolet (UV ) Fe ii 2100Y3050 8 emission complex. We calculate a grid of Fe ii emission spectra representative of BLR clouds and compare them with the observed I Zw 1 spectrum. Our predicted spectrum for log n H /(cm À3 ) ½ ¼ 11:0, log È H /(cm À2 s À1 ) ½ ¼ 20:5, and /(1 km s À1 ) ¼ 20, using Cloudy and an 830 level model atom for Fe ii with energies up to 14.06 eV, gives a better fit to the UV Fe ii emission than models with fewer levels. Our analysis indicates (1) the observed UV Fe ii emission must be corrected for an underlying Fe ii pseudocontinuum; (2) Fe ii emission peaks can be misidentified as that of other ions in active galactic nuclei (AGNs) with narrow-lined BLRs possibly affecting deduced physical parameters; (3) the shape of 4200Y4700 8 Fe ii emission in I Zw 1 and other AGNs is a relative indicator of narrow-line region ( NLR) and BLR Fe ii emission; (4) predicted ratios of Ly , C iii], and Fe ii emission relative to Mg ii k2800 agree with extinction corrected observed I Zw 1 fluxes, except for C iv k1549; (5) the sensitivity of Fe ii emission strength to microturbulence casts doubt on existing relative Fe/ Mg abundances derived from Fe ii (UV)/Mg ii flux ratios. Our calculated Fe ii emission spectra, suitable for BLRs in AGNs, are available at

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“…The radiation from luminous quasi-stellar objects (QSOs) can currently be studied up to redshift 6.5 and thus allows one to probe, over much of the universe's age, the properties of their central black holes (BHs; e.g., Willott et al 2003), their broadline region (BLR; e.g., Freudling et al 2003), and the ionization state of intergalactic gas (e.g., Fan et al 2006b). The most distant QSOs are of importance for both the study of galaxy evolution and large-scale structure.…”

Section: Introductionmentioning

confidence: 99%

NEAR-INFRARED SPECTROSCOPY OF SDSS J0303 – 0019: A LOW-LUMINOSITY, HIGH-EDDINGTON-RATIO QUASAR ATz∼ 6

Kurk

Walter

Fan³

et al. 2009

ApJ

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We present sensitive near-infrared (NIR) VLT ISAAC spectroscopic observations of the z = 6.08 quasar SDSS J030331.40-001912.9. This quasi-stellar object (QSO) is more than a magnitude fainter than other QSOs at z ∼ 6 for which NIR spectroscopy has been obtained to date and is therefore presumably more representative of the QSO population at the end of cosmic reionization. Combining rest-frame UV continuum luminosity with the width measurements of the Mg ii and C iv lines, we derive a black hole mass of 2 +1.0 −0.5 × 10 8 M , the lowest mass observed for z ∼ 6 QSOs to date, and derive an Eddington ratio of 1.6 +0.4 −0.6 , among the highest value derived for QSOs at any redshift. The Spitzer 24 μm nondetection of this QSO does not leave space for a significant hot dust component in its optical/NIR spectral energy distribution, in common with one other faint QSO at z = 6, but in contrast to more than 20 more z = 6 QSOs and all known lower redshift QSOs with sufficiently deep multiwavelength photometry. We conclude that we have found evidence for differences in the intrinsic properties of at least one z ∼ 6 QSO as compared to the lower redshift population.

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Iron Emission in z 6 QSO s

Cited by 109 publications

References 31 publications

Genesis and evolution of dust in galaxies in the early Universe

Genesis and evolution of dust in galaxies in the early Universe

Modeling FeiiEmission and Revised Feii(UV) Empirical Templates for the Seyfert 1 Galaxy I Zw 1

NEAR-INFRARED SPECTROSCOPY OF SDSS J0303 – 0019: A LOW-LUMINOSITY, HIGH-EDDINGTON-RATIO QUASAR ATz∼ 6

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