Quasar Black Hole Mass Estimates from High-Ionization Lines: Breaking a Taboo?
Can high ionization lines such as CIV lambda 1549 provide useful virial broadening estimators for computing the mass of the supermassive black holes that power the quasar phenomenon? The question has been dismissed by several workers as a rhetorical one because blue-shifted, non-virial emission asso...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/383803 |
| Acceso en línea: | http://hdl.handle.net/10261/383803 |
| Access Level: | acceso abierto |
| Palabra clave: | Ionization processes Emission line formation Atomic spectroscopy Supermassive black holes Rmission line profiles Quasars |
| Sumario: | Can high ionization lines such as CIV lambda 1549 provide useful virial broadening estimators for computing the mass of the supermassive black holes that power the quasar phenomenon? The question has been dismissed by several workers as a rhetorical one because blue-shifted, non-virial emission associated with gas outflows is often prominent in CIV lambda 1549 line profiles. In this contribution, we first summarize the evidence suggesting that the FWHM of low-ionization lines like H beta and MgII lambda 2800 provide reliable virial broadening estimators over a broad range of luminosity. We confirm that the line widths of CIV lambda 1549 is not immediately offering a virial broadening estimator equivalent to the width of low-ionization lines. However, capitalizing on the results of Coatman et al. (2016) and Sulentic et al. (2017), we suggest a correction to FWHM CIV l 1549 for Eddington ratio and luminosity effects that, however, remains cumbersome to apply in practice. Intermediate ionization lines (IP similar to 20-30 eV; AlIII lambda 1860 and SiIII] lambda 1892) may provide a better virial broadening estimator for high redshift quasars, but larger samples are needed to assess their reliability. Ultimately, they may be associated with the broad-line region radius estimated from the photoionization method introduced by Negrete et al. (2013) to obtain black hole mass estimates independent from scaling laws. © 2017 by the authors. |
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