NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-04-19 T21:54:36 PDT
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For refcode 2014MNRAS.438..557Z:
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NED Abstract

Copyright by Royal Astronomical Society. 2014MNRAS.438..557Z Optically selected BLR-less active galactic nuclei from the SDSS Stripe82 Database - I. The sample Zhang, Xue-Guang Abstract. This is the first paper in a dedicated series to study the properties of the optically-selected broad-line-region-less (BLR-less) active galactic nuclei (AGNs; with no-hidden central broad emission line regions). We carried out a systematic search for the BLR-less AGNs through the Sloan Digital Sky Survey Legacy Survey (SDSS Stripe82 Database). Based on the spectral decomposition results for all the 136 676 spectroscopic objects (galaxies and quasars) with redshift less than 0.35 covered by the SDSS Stripe82 region, our spectroscopic sample for the BLR-less AGNs includes 22 693 pure narrow line objects without broad emission lines but with apparent AGN continuum emission R_AGN_ > 0.3 and apparent stellar lights R_ssp_ > 0.3. Then, using the properties of the photometry magnitude RMS (RMS) and Pearson's coefficients (R_1, 2_) between two different SDSS band light curves: RMS_k>3x RMS_{M_k}_ and R_1, 2_ > ~0.8, the final 281 pure narrow line objects with true photometry variabilities are our selected reliable candidates for the BLR-less AGNs. The selected candidates with higher confidence levels not only have the expected spectral features of the BLR-less AGNs, but also show significant true photometry variabilities. The reported sample enlarges at least four times the current sample of the BLR-less AGNs, and will provide more reliable information to explain the lack of the BLRs of AGNs in our following studies. Key words: galaxies: active, galaxies: nuclei, quasars: emission lines, galaxies: Seyfert
Retrieve 235 NED objects in this reference.
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