Browsing by Author "Meyer, Eileen T."

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    Collective Evidence for Inverse Compton Emission from External Photons in High-Power Blazars
    (The American Astronomical Society, 2012) Meyer, Eileen T.; Fossati, Giovanni; Georganopoulos, Markos; Lister, Matthew L.
    We present the first collective evidence that Fermi-detected jets of high kinetic power (L kin) are dominated by inverse Compton emission from upscattered external photons. Using a sample with a broad range in orientation angle, including radio galaxies and blazars, we find that very high power sources (L kin > 1045.5 erg s–1) show a significant increase in the ratio of inverse Compton to synchrotron power (Compton dominance) with decreasing orientation angle, as measured by the radio core dominance and confirmed by the distribution of superluminal speeds. This increase is consistent with beaming expectations for external Compton (EC) emission, but not for synchrotron self-Compton (SSC) emission. For the lowest power jets (L kin < 1043.5 erg s–1), no trend between Compton and radio core dominance is found, consistent with SSC. Importantly, the EC trend is not seen for moderately high power flat spectrum radio quasars with strong external photon fields. Coupled with the evidence that jet power is linked to the jet speed, this finding suggests that external photon fields become the dominant source of seed photons in the jet comoving frame only for the faster and therefore more powerful jets.
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    The effects of intrinsic spectral curvature and flux limits on the measured evolutionary behavior of BL Lacertæ objects
    (2008) Meyer, Eileen T.; Fossati, Giovanni
    The effects of modeling the intrinsic curvature of the spectral energy distributions of BL Lacertae objects in the soft x-ray on the V/V M evolutionary statistic were studied. It was found that the power law approximations in the soft x-ray could cause a significant bias in V/V M towards values supporting either negative or positive evolution for BL Lacs. The effects of such a bias on the Sedentary Survey, a large sample of 150 BL Lacertae objects, were found to be negligible on average though individual effects were appreciable. The luminosity function and parametric values of evolution for pure luminosity and pure density evolution were computed for the Sedentary Sample.