Show simple item record

dc.contributor.authorBianchi, Stefano
dc.contributor.authorPanessa, Francesca
dc.contributor.authorBarcons Jáuregui, Xavier
dc.contributor.authorCarrera Troyano, Francisco Jesús 
dc.contributor.authorLa Franca, Fabio
dc.contributor.authorMatt, Giorgio
dc.contributor.authorOnori, Francesca
dc.contributor.authorWolter, Anna
dc.contributor.authorCorral Ramos, Amalia
dc.contributor.authorMonaco, Lorenzo
dc.contributor.authorRuiz Camuñas, Ángel
dc.contributor.authorBrightman, Murray
dc.contributor.otherUniversidad de Cantabriaes_ES
dc.date.accessioned2013-12-26T11:32:31Z
dc.date.available2013-12-26T11:32:31Z
dc.date.issued2012-11
dc.identifier.issn0035-8711
dc.identifier.issn1365-2966
dc.identifier.urihttp://hdl.handle.net/10902/4084
dc.description.abstractWe present the results of a campaign of simultaneous X-ray and optical observations of ‘true’ type 2 Seyfert galaxies candidates, i.e. active galactic nuclei without a broad-line region (BLR). Out of the initial sample composed of eight sources, one object, IC 1631, was found to be a misclassified starburst galaxy, another, Q2130−431, does showbroad optical lines, while other two, IRAS 01428−0404 and NGC 4698, are very likely absorbed by Compton-thick gas along the line of sight. Therefore, these four sources are not unabsorbed Seyfert 2s as previously suggested in the literature. On the other hand, we confirm that NGC 3147, NGC 3660 and Q2131−427 belong to the class of true type 2 Seyfert galaxies, since they do not show any evidence for a broad component of the optical lines nor for obscuration in their X-ray spectra. These three sources have low accretion rates (˙m = Lbol/LEdd<~0.01), in agreement with theoretical models which predict that the BLR disappears below a critical value of Lbol/LEdd. The last source, Mrk 273x, would represent an exception even of these accretion-dependent versions of the Unification Models, due to its high X-ray luminosity and accretion rate, and no evidence for obscuration. However, its optical classification as a Seyfert 2 is only based on the absence of a broad component of Hβ, due to the lack of optical spectra encompassing the Hα band.es_ES
dc.format.extent16 p.es_ES
dc.language.isoenges_ES
dc.publisherThe Royal Astronomical Societyes_ES
dc.rights© 2012 The Authors © 2012 The Royal Astronomical Societyes_ES
dc.sourceMonthly Notices of the RAS, Vol. 426, Iss. 4, Pag. 3225-3240 (2012)es_ES
dc.subject.otherGalaxies: activees_ES
dc.subject.otherGalaxies: Seyfertes_ES
dc.titleSimultaneous X-ray and optical observations of true type 2 Seyfert galaxieses_ES
dc.typeinfo:eu-repo/semantics/articlees_ES
dc.relation.publisherVersionhttp://dx.doi.org/10.1111/j.1365-2966.2012.21959.xes_ES
dc.rights.accessRightsopenAccesses_ES
dc.identifier.DOI10.1111/j.1365-2966.2012.21959.x
dc.type.versionpublishedVersiones_ES


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record