J/A+A/696/A110ivo://CDS.VizieR/J/A+A/696/A110doi:10.26093/cds/vizier.36960110CDSCunha P.A.C.Humphrey A.Brinchmann J.Paulino-Afonso A.Bisigello L.,Bolzonella M.Vaz D.2026-05-06T20:02:48Z2025-04-09T13:20:48ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frsurveysquasarsactive-galactic-nucleivisible-astronomyinfrared-astronomyActive galactic nuclei (AGNs) play a vital role in the evolution of galaxies over cosmic time, significantly influencing their star formation and growth. As obscured AGNs are difficult to identify due to obscuration by gas and dust, our understanding of their full impact is still under study. It is essential to investigate their properties and distribution, in particular type II quasars (QSO2s), to comprehensively account for AGN populations and understand how their fraction evolves over time. Such studies provide critical insights into the co-evolution of AGNs and their host galaxies. Following our previous study, where a machine learning approach was applied to identify 366 QSO2 candidates from SDSS and WISE surveys (median z~1.1), we now aim to characterise this QSO2 candidate sample by analysing their spectral energy distributions (SEDs) and deriving their physical properties. We estimated relevant physical properties of the QSO2 candidates, including the star formation rate (SFR), stellar mass (M*), AGN luminosity, and AGN fraction, using SED fitting with CIGALE. We compared the inferred properties with analogous populations in the semi-empirical simulation SPRITZ, placing these results in the context of galaxy evolution. The physical properties derived for our QSO2 candidates indicate a diverse population of AGNs at various stages of evolution. QSO2 candidates cover a wide range in the SFR-M* diagram, with numerous high-SFR sources lying above the main sequence at their redshift, suggesting a link between AGN activity and enhanced star formation. Additionally, we identify a population of apparently quenched galaxies, which may be due to obscured star formation or AGN feedback. Furthermore, the physical parameters of our sample align closely with those of composite systems and type 2 AGNs from SPRITZ, supporting the classification of these candidates as obscured AGNs. This study confirms that our QSO2 candidates, selected via a machine learning approach, exhibit properties consistent with being AGN-host galaxies. This method can identify AGNs within large galaxy samples by considering AGN fractions and their contributions to the infrared luminosity, going beyond the limitations of traditional colour-colour selection techniques. The diverse properties of our candidates demonstrate the capability of this approach to identify complex AGN-host systems that might otherwise be missed. This shows the help that machine learning can provide in refining AGN classifications and advancing our understanding of galaxy evolution driven by AGN activity with new target selection.2025A&A...696A.110Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/696/A110CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)III/286 : APOGEE-2 DR17 final allStar catalog (Abdurro'uf+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/696/A110https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/696/A110http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/696/A110https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/696/A110https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/696/A110http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/696/A110GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/696/A110/catalog (CIGALE QSO2 catalogue)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/696/A110/catalog?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/696/A110/catalog?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/696/A110/catalog?GETtext/xml+votable180.050000true21.575928-3.90735640.0055555555555555566/10 36 684 689 747 750 2052 2057 2059-2060 2069 2113 2134 2149 2160 2168 2191 2203 2241 2563 4310 4318 4338 4371 4373 4378-4379 4397 4399 4416 4452 4469 4485 4495-4497 4500 4506 4513-4514 4517-4518 4539 4555 4560 4579 4587 4596 4600 4602 4689 4694 4709 4719 4733 4783 4821 4829 4831 4847 4859 4895 4899 4901 4904 4945 4947 4950 4965 4973-4974 4976 5001 5034 5089 5137 5139 5142 5144 5146 5151 5159 5171 5181 5185 5187 5190 5192 5218 5224 5226 5228 5269 5276-5277 5281 5287 5291 5296 5318 5325 5354 5386 5404 5466 5486 5493 5546 5551 5615 5759 5777 5826 5975 6025 6113 6441 6469 6473 6475 6488 6579 6585 6650 7180 7190 7221 7245 7290 7312 7352 7393 7400 9183 9608 9750 9787 9832 9836 9849 9961 9994 10026 10438 10441 10454 10461 10562 10585 10619 10669 10724 10727 10743 10792 10926 11146 11191 11268 11292 11308 11424 11430 11454 11489 12634 13341 13357 17366-17367 17373 17395 17397 17403 17407 17622-17623 17625 17639 17641 17650-17651 17654-17655 17657 17663 17672 17684 17686 17688-17689 17691-17692 17695 17701-17703 17710 17717 17721 17736-17738 17753-17756 17759-17760 17763 17768 17771 17774 17776-17777 17786-17789 17793 17797 17808-17809 17817 17819-17820 17823 17827 17831-17832 17844 17846 17848 17851-17852 17862 17864 17866 17873 17880 17890 17893 17906 17943 17963 17967 17970 17979 17988-17989 17994 17998 18002 18008-18009 18018-18019 18025 18032 18034 18039 18062-18063 18068-18069 18073 18086 18089 18092 18096 18103 18106 18109 18114 18134 18148 18177 18185 18197 18212 18292 18317 18679 18684 18771 18773 18776 18780 18784 18791 18794 18796 18810 18832 18835 18839 18850 18853 18880 18884 18910 19026 19034 19036 19048 19060 19064 19093 19122 19462 19465 19473 19497 19631 19771 19775 19781 19798 19800 19882 19908 20089 20094 20240 20277 20333 20429-20430 20452 28351 28386 28394 28398 28510 28585 28603 28628 28640 36842-36843 36859-36860https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/696/A110?format=asciiOpticalInfrareddefaultJ/A+A/696/A110/catalogCIGALE QSO2 cataloguerecnoRecord number assigned by the VizieR team. 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