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Statistics of superluminal sources

Cohen, Marshall H. (1989) Statistics of superluminal sources. In: BL Lac Objects. Lecture Notes in Physics. No.334. Springer-Verlag , Berlin/Heidelberg, pp. 13-21. ISBN 978-3-540-51389-6.

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The probability density that a randomly selected beamed source lies at angle θ to the line of sight is shown in Fig. 3. For reasonable values of the Lorentz factor, the Doppler boost exponent and the N(S) exponent, p(θ) peaks at a few degrees, well inside the angle for maximum apparent transverse velocity. Theoretical distributions of the apparent transverse velocity are sharply peaked near the maximum possible value, but the observed distribution is peaked at low velocities. Some of the difference is due to the inhomogeneous nature of the sample. BL Lacs have a lower average velocity than quasars. From a purely statistical point of view this might be due to their being the low-θ tail of the quasar distribution; this also would help to explain the rapid intensity variations and high continuum/line ratios. However this explanation is unlikely, because the redshift distributions are so different.

Item Type:Book Section
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Additional Information:© Springer-Verlag 1989. I am grateful to the Lick Observatory, where some of this work was done, and to Tim Pearson for helpful comments. This work was supported by NSF Grant AST 85-09822.
Funding AgencyGrant Number
NSFAST 85-09822
Subject Keywords:Proper Motion; Lorentz Factor; Virgo Cluster; Redshift Distribution; Doppler Factor
Series Name:Lecture Notes in Physics
Issue or Number:334
Record Number:CaltechAUTHORS:20201008-131242874
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:105941
Deposited By: George Porter
Deposited On:08 Oct 2020 20:23
Last Modified:16 Nov 2021 18:48

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