Abstrakti
Context. Blazar population models have shown that the inverseCompton and variability Doppler factor estimates yield consistent results at the population level for flat spectrum radio quasars (FSRQs). The two methods, however, are inconsistent when compared on a sourcebysource basis. Aims. In this work, we attempt to understand the source of the discrepancy by tracing the potential sources of systematic and statistical error for the inverseCompton Doppler factors. By eliminating these sources of error, we provide stronger constrains on the value of the Doppler factor in blazar jets. Methods. We reestimate the inverseCompton Doppler factor for 11 sources that meet certain criteria for their synchrotron peak frequency and the availability of Doppler factor estimates in the literature. We compare these estimates with the average of two different estimates of the variability Doppler factor obtained using various datasets and methodologies to identify any discrepancies and, in each case, trace their sources in the methodology or assumptions adopted. Results. We identify three significant sources of error for the inverseCompton Doppler factors: a) contamination of the Xray flux by nonsynchrotron selfCompton emission; b) radio observations at frequencies other than the synchrotron turnover frequency; c) nonsimultaneity between radio and Xray observations. We discuss key aspects in the correct application of the inverseCompton method in light of these potential errors. We are able to constrain the Doppler factor of 3C 273, 3C 345, 3C 454.3, PKS 1510089, and PKS 1633+382 effectively, since all available estimates from both methods converge to the same values for these five sources.
Alkuperäiskieli  Englanti 

Artikkeli  A104 
Sivumäärä  8 
Julkaisu  Astronomy and Astrophysics 
Vuosikerta  602 
DOI  pysyväislinkit  
Tila  Julkaistu  1 kesäk. 2017 
OKMjulkaisutyyppi  A1 Julkaistu artikkeli, soviteltu 
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