Strong [O III] Objects Among SDSS Broad-Line Active Galaxies
| Autor: | Ludwig, Randi R., Wills, Beverley, Greene, Jenny E., Robinson, Edward L. |
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| Rok vydání: | 2009 |
| Předmět: | |
| Zdroj: | Astrophys.J.706:995-1007,2009 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0004-637X/706/2/995 |
| Popis: | We present the results of a spectral principal component analysis on 9046 broad-line AGN from the Sloan Digital Sky Survey. We examine correlations between spectral regions within various eigenspectra (e.g., between Fe II strength and H$\beta$ width) and confirm that the same trends are apparent in spectral measurements, as validation of our technique. Because we found that our sample had a large range in the equivalent width of [O III] $\lambda$5007, we divided the data into three subsets based on [O III] strength. Of these, only in the sample with the weakest equivalent width of [O III] were we able to recover the known correlation between [O III] strength and full width at half maximum of H$\beta$ and their anticorrelation with Fe II strength. At the low luminosities considered here ($L_{5100 \AA}$ of $10^{42}-10^{46}$ erg s$^{-1}$), interpretation of the principal components is considerably complicated particularly because of the wide range in [O III] equivalent width. We speculate that variations in covering factor are responsible for this wide range in [O III] strength. Comment: 26 pages, 11 figures, published in ApJ |
| Databáze: | arXiv |
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