Echo Mappping of the Broad Line Region of AGNs -- A Critical Appraisal
| dc.creator | Maoz, Dan | |
| dc.date | 1994-07-06 | |
| dc.date.accessioned | 2026-07-07T02:19:16Z | |
| dc.date.available | 2026-07-07T02:19:16Z | |
| dc.description | The results of recent AGN monitoring campaigns confirm the ``big picture'' of the echo paradigm, but the details of the emission-line light curves cannot be accurately reproduced with only the simplest assumptions, some of which must be invalid. I discuss possible solutions. I present some preliminary optical light curves from Wise Observatory for NGC 4151 during the December 1993 multi-satellite campaign. The optical data show a continuity with the complex behavior observed in the IUE data, and may explain the peculiarities in emission-line response seen in this and other AGNs. I review some recent results on quasar emission line variability from the Steward-Wise PG quasar monitoring program, which allow extension of the observed AGN BLR Radius--Luminosity relation to higher luminosities than previously feasible. Agreement with the expected $R\propto L^{1/2}$ relation is suggested. Finally, I criticize the trend to attribute significance to the details of transfer functions recovered by inversion techniques. I show, as an example, that the model emission-line light curves produced by convolving the 5-year continuum light curve of NGC 5548 with transfer functions peaked at zero or non-zero lag have differences much smaller that the uncertainties in the H$β$ light curve. Transfer functions of both kinds can reproduce the data equally well. I emphasize the need to use modeling, rather than inversion methods, in order to delineate the regions of BLR parameter space allowed and ruled out by the data. | |
| dc.description | uuencoded compressed PostScript, incl. figures. Also available by anonymous ftp to wise3.tau.ac.il pub/dani/echocrit.uu Wise-940706 | |
| dc.identifier | https://arxiv.org/abs/astro-ph/9407017 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/9407017 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/9800 | |
| dc.subject | Astrophysics | |
| dc.title | Echo Mappping of the Broad Line Region of AGNs -- A Critical Appraisal | |
| dc.type | text |