Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/31703
DC Field | Value | Language |
---|---|---|
dc.contributor.author | Yang, Jinyi | en_US |
dc.contributor.author | Wang, Feige | en_US |
dc.contributor.author | Fan, Xiaohui | en_US |
dc.contributor.author | Barth, Aaron J. | en_US |
dc.contributor.author | Hennawi, Joseph F. | en_US |
dc.contributor.author | NANNI, RICCARDO | en_US |
dc.contributor.author | Bian, Fuyan | en_US |
dc.contributor.author | Davies, Frederick B. | en_US |
dc.contributor.author | Farina, Emanuele P. | en_US |
dc.contributor.author | Schindler, Jan Torge | en_US |
dc.contributor.author | Bañados, Eduardo | en_US |
dc.contributor.author | DECARLI, ROBERTO | en_US |
dc.contributor.author | Eilers, Anna Christina | en_US |
dc.contributor.author | Green, Richard | en_US |
dc.contributor.author | Guo, Hengxiao | en_US |
dc.contributor.author | Jiang, Linhua | en_US |
dc.contributor.author | Li, Jiang Tao | en_US |
dc.contributor.author | Venemans, Bram | en_US |
dc.contributor.author | Walter, Fabian | en_US |
dc.contributor.author | Wu, Xue Bing | en_US |
dc.contributor.author | Yue, Minghao | en_US |
dc.date.accessioned | 2022-03-18T13:20:07Z | - |
dc.date.available | 2022-03-18T13:20:07Z | - |
dc.date.issued | 2021 | en_US |
dc.identifier.issn | 0004-637X | en_US |
dc.identifier.uri | http://hdl.handle.net/20.500.12386/31703 | - |
dc.description.abstract | We report the results of near-infrared spectroscopic observations of 37 quasars in the redshift range 6.3 < z ≤ 7.64, including 32 quasars at z > 6.5, forming the largest quasar near-infrared spectral sample at this redshift. The spectra, taken with Keck, Gemini, VLT, and Magellan, allow investigations of central black hole mass and quasar rest-frame ultraviolet spectral properties. The black hole masses derived from the Mg ii emission lines are in the range (0.3–3.6) × 109 M ⊙, which requires massive seed black holes with masses ≳103–104 M ⊙, assuming Eddington accretion since z = 30. The Eddington ratio distribution peaks at λ Edd ∼ 0.8 and has a mean of 1.08, suggesting high accretion rates for these quasars. The C iv–Mg ii emission-line velocity differences in our sample show an increase of C iv blueshift toward higher redshift, but the evolutionary trend observed from this sample is weaker than the previous results from smaller samples at similar redshift. The Fe ii/Mg ii flux ratios derived for these quasars up to z = 7.6, compared with previous measurements at different redshifts, do not show any evidence of strong redshift evolution, suggesting metal-enriched environments in these quasars. Using this quasar sample, we create a quasar composite spectrum for z > 6.5 quasars and find no significant redshift evolution of quasar broad emission lines and continuum slope, except for a blueshift of the C iv line. Our sample yields a strong broad absorption line quasar fraction of ∼24%, higher than the fractions in lower-redshift quasar samples, although this could be affected by small sample statistics and selection effects. | en_US |
dc.language.iso | eng | en_US |
dc.title | Probing Early Supermassive Black Hole Growth and Quasar Evolution with Near-infrared Spectroscopy of 37 Reionization-era Quasars at 6.3 < z ≤ 7.64 | en_US |
dc.type | Article | - |
dc.identifier.doi | 10.3847/1538-4357/ac2b32 | en_US |
dc.identifier.scopus | 2-s2.0-85123247588 | en_US |
dc.identifier.url | https://iopscience.iop.org/article/10.3847/1538-4357/ac2b32 | en_US |
dc.identifier.url | https://api.elsevier.com/content/abstract/scopus_id/85123247588 | en_US |
dc.relation.medium | STAMPA | en_US |
dc.relation.volume | 923 | en_US |
dc.relation.issue | 2 | en_US |
dc.relation.firstpage | 262 | en_US |
dc.type.referee | REF_1 | en_US |
dc.description.international | sì | en_US |
dc.relation.scientificsector | FIS/05 - ASTRONOMIA E ASTROFISICA | en_US |
dc.relation.journal | THE ASTROPHYSICAL JOURNAL | en_US |
dc.type.miur | 262 Articolo in rivista | - |
dc.relation.ercsector | ERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation | en_US |
dc.description.apc | no | en_US |
dc.description.oa | 1 – prodotto con file in versione Open Access (allegare il file al passo 5-Carica) | en_US |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.openairetype | Article | - |
item.languageiso639-1 | en | - |
item.cerifentitytype | Publications | - |
item.grantfulltext | open | - |
item.fulltext | With Fulltext | - |
crisitem.author.dept | OAS Bologna | - |
crisitem.author.orcid | 0000-0002-2662-8803 | - |
crisitem.journal.journalissn | 0004-637X | - |
crisitem.journal.ance | E016252 | - |
Appears in Collections: | 1.01 Articoli in rivista |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
2109.13942 compr.pdf | preprint | 2.51 MB | Adobe PDF | View/Open |
Yang_2021_ApJ_923_262.pdf | [Administrators only] | 2.99 MB | Adobe PDF |
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