|Author||Singh, V. ♦ Shastri, P. ♦ Risaliti, G.|
|Source||Indian Institute of Astrophysics|
|Subject Domain (in DDC)||Natural sciences & mathematics ♦ Physics|
|Subject Keyword||Galaxies: Seyfert ♦ X-rays: galaxies ♦ Galaxies: active|
|Description||Context. The unification scheme of Seyfert galaxies hypothesizes that Seyfert type 1s and type 2s are intrinsically similar and the observed differences between the two subtypes are solely due to the differing orientations of toroidal-shaped obscuring material around the AGN. In the framework of the unification scheme, both the Seyfert subtypes are expected to show similar intrinsic nuclear properties such as the absorption-corrected AGN X-ray luminosity, bolometric luminosity, accretion rate and the mass of the supermassive black hole. Aims. To test the predictions of the Seyfert unification scheme, we make statistical comparison of the distributions of: (i) the absorption-corrected 2.0–10 keV X-ray luminosities; (ii) the bolometric luminosities; (iii) the black hole masses and; (iv) the Eddington ratios, of Seyfert type 1s and type 2s. Methods. We use an optically selected Seyfert sample in which type 1s and type 2s are matched in properties that are independent to the orientation of the obscuring torus, the AGN axis and the host galaxy. Results. The distributions of the absorption-corrected 2.0–10 keV X-ray luminosities (), the bolometric luminosities (LBol), the black masses (MBH) and, the Eddington ratios (λ) are statistically similar for the two Seyfert subtypes, consistent with the orientation and obscuration based Seyfert unification scheme. The Eddington ratio distributions suggest that both the Seyfert subtypes are accreting at sub-Eddington level with wide span of Eddington ratios i.e.,10-4–10-1.|
|Education Level||UG and PG|
|Learning Resource Type||Article|
|Publisher Institution||EDP Sciences|
|Journal||Astronomy & Astrophysics|
Ministry of Human Resource Development (MHRD) under its National Mission on Education through Information and Communication Technology (NMEICT) has initiated the National Digital Library of India (NDL India) pilot project to develop a framework of virtual repository of learning resources with a single-window search facility. Filtered and federated searching is employed to facilitate focused searching so that learners can find out the right resource with least effort and in minimum time. NDL India is designed to hold content of any language and provides interface support for leading Indian languages. It is being arranged to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular form of access devices and differently-abled learners. It is being developed to help students to prepare for entrance and competitive examination, to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. The pilot project is devising a framework that is being scaled up with respect to content volume and diversity to serve all levels and disciplines of learners. It is being developed at Indian Institute of Technology Kharagpur.
NDL India is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with respective organization from where the contents are sourced and NDL India has no responsibility or liability for these. Every effort is made to keep the NDL India portal up and running smoothly. However, NDL India takes no responsibility for, and will not be liable for, the portal being unavailable due to technical issues or otherwise.
Ministry of Human Resource Development (MHRD), through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDL India) pilot project.
For any issue or feedback, please write to email@example.com
COVID-19 Lockdown not to affect your study. Study through National Digital Library of India (NDLI).