Astronomy and Astrophysics – Astrophysics
Scientific paper
2002-07-14
Astronomy and Astrophysics
Astrophysics
3 pages
Scientific paper
In a recent paper, McLure & Jarvis (2002, astro-ph/0204473, v.1) reanalyze AGN broad-line reverberation measurements presented in Kaspi et al. (2000). They find the broad-line region size and the AGN luminosity at 5100 Ang can be related by R_{BLR} ~ L_{5100}^{0.5}. This differs from the result of Kaspi et al., who found R_{BLR} ~ L_{5100}^{0.7}, a departure from expectations for a constant ionization parameter. In this note I investigate the source of the discrepancy. McLure & Jarvis use quasar luminosities based on the single-epoch, multichannel-spectrophotometer measurements of Neugebauer et al. (1987), obtained in 1980. I show that the Neugebauer et al. fluxes are systematically higher, by a constant flux offset, compared with the multi-epoch CCD measurements of Kaspi et al., obtained concurrently with the echo-mapping radii. In addition, McLure & Jarvis erred when converting these fluxes to luminosities. The two effects compound to a typical factor 2 (0.3 dex) overestimate of the luminosities of the PG quasars in the sample. Since McLure & Jarvis did adopt the Seyfert luminosities in Kaspi et al. (2000), they obtained a slope that is flatter by 0.2.
No associations
LandOfFree
Comment on "Measuring the black hole masses of high redshift quasars" does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Comment on "Measuring the black hole masses of high redshift quasars", we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Comment on "Measuring the black hole masses of high redshift quasars" will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-645855