@article{02442ab5900b4c8990c7454e7e27ad30,
title = "Measurement of the broad-line region size in two bright quasars",
abstract = "We present 4 years of spectrophotometric monitoring data for two radio-quiet quasars, PG 0804+762 and PG 0953+414, with typical sampling intervals of several months. Both sources show continuum and emission-line variations. The variations of the Hβ line follow those of the continuum with a time lag, as derived from a cross-correlation analysis, of 93 ± 30 days for PG 0804+762 and 111 ± 55 days for PG 0953+414. This is the first reliable measurement of such a lag in active galactic nuclei with luminosity L > 1045 ergs s-1. The broad-line region (BLR) size that is implied is almost an order of magnitude larger than that measured in several Seyfert 1 galaxies and is consistent with the hypothesis that the BLR size grows as L0.5.",
keywords = "Galaxies: active, Quasars: emission lines",
author = "Shai Kaspi and Smith, {Paul S.} and Dan Maoz and Hagai Netzer and Jannuzi, {Buell T.}",
note = "Funding Information: We thank John Dan and the Wise Observatory staff for their expert assistance with the observations. We are grateful to Tal Alexander for illuminating discussions and to the anonymous referee for several constructive comments. Astronomy at the Wise Observatory is supported by grants from the Israel Academy of Science. Monitoring of PG quasars at Steward Observatory is supported by NASA grant NAG 5-1630. B. T. J. acknowledges support from the National Optical Astronomy Observatories, which is operated by AURA, Inc., on behalf of the National Science Foundation.",
year = "1996",
doi = "10.1086/310339",
language = "אנגלית",
volume = "471",
pages = "L75--L78",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "American Astronomical Society",
number = "2 PART II",
}