Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/26435
DC Field | Value | Language |
---|---|---|
dc.contributor.author | Yang, G. | en_US |
dc.contributor.author | Brandt, W. N. | en_US |
dc.contributor.author | Luo, B. | en_US |
dc.contributor.author | Xue, Y. Q. | en_US |
dc.contributor.author | Bauer, F. E. | en_US |
dc.contributor.author | Sun, M. Y. | en_US |
dc.contributor.author | Kim, S. | en_US |
dc.contributor.author | Schulze, S. | en_US |
dc.contributor.author | Zheng, X. C. | en_US |
dc.contributor.author | Paolillo, Maurizio | en_US |
dc.contributor.author | Shemmer, O. | en_US |
dc.contributor.author | Liu, T. | en_US |
dc.contributor.author | Schneider, D. P. | en_US |
dc.contributor.author | Vignali, C. | en_US |
dc.contributor.author | Vito, F. | en_US |
dc.contributor.author | Wang, J. -X. | en_US |
dc.date.accessioned | 2020-07-14T08:46:17Z | - |
dc.date.available | 2020-07-14T08:46:17Z | - |
dc.date.issued | 2016 | en_US |
dc.identifier.issn | 0004-637X | en_US |
dc.identifier.uri | http://hdl.handle.net/20.500.12386/26435 | - |
dc.description.abstract | We perform long-term (≈15 years, observed-frame) X-ray variability analyses of the 68 brightest radio-quiet active galactic nuclei (AGNs) in the 6 Ms Chandra Deep Field-South survey; the majority are in the redshift range of 0.6-3.1, providing access to penetrating rest-frame X-rays up to ≈10-30 keV. Of the 68 sources, 24 are optical spectral type I AGNs, and the rest (44) are type II AGNs. The timescales probed in this work are among the longest for X-ray variability studies of distant AGNs. Photometric analyses reveal widespread photon flux variability: 90% of AGNs are variable above a 95% confidence level, including many X-ray obscured AGNs and several optically classified type II quasars. We characterize the intrinsic X-ray luminosity ({L}<SUB>{{X</SUB>}}) and absorption ({N}<SUB>{{H</SUB>}}) variability via spectral fitting. Most (74%) sources show {L}<SUB>{{X</SUB>}} variability; the variability amplitudes are generally smaller for quasars. A Compton-thick candidate AGN shows variability of its high-energy X-ray flux, indicating the size of reflecting material to be ≲0.3 pc. {L}<SUB>{{X</SUB>}} variability is also detected in a broad absorption line quasar. The {N}<SUB>{{H</SUB>}} variability amplitude for our sample appears to rise as time separation increases. About 16% of sources show {N}<SUB>{{H</SUB>}} variability. One source transitions from an X-ray unobscured to obscured state, while its optical classification remains type I; this behavior indicates the X-ray eclipsing material is not large enough to obscure the whole broad-line region. | en_US |
dc.language.iso | eng | en_US |
dc.title | Long-term X-Ray Variability of Typical Active Galactic Nuclei in the Distant Universe | en_US |
dc.type | Article | - |
dc.identifier.doi | 10.3847/0004-637X/831/2/145 | en_US |
dc.identifier.scopus | 2-s2.0-84994524483 | en_US |
dc.identifier.isi | 000400474300009 | en_US |
dc.identifier.url | https://iopscience.iop.org/article/10.3847/0004-637X/831/2/145 | en_US |
dc.relation.medium | STAMPA | en_US |
dc.relation.volume | 831 | en_US |
dc.relation.issue | 2 | en_US |
dc.relation.firstpage | 145 | en_US |
dc.type.referee | REF_1 | en_US |
dc.description.international | sì | en_US |
dc.contributor.country | ITA | en_US |
dc.contributor.country | USA | en_US |
dc.contributor.country | CHN | 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.identifier.adsbibcode | 2016ApJ...831..145Y | en_US |
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 | O.A. Capodimonte | - |
crisitem.author.orcid | 0000-0003-4210-7693 | - |
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 | |
---|---|---|---|---|
Yang_2016_ApJ_831_145.pdf | Pdf editoriale | 1.85 MB | Adobe PDF | View/Open |
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