The estimation of γ-ray Doppler factor for Fermi/LAT-detected blazars

Blazars are a subclass of active galactic nuclei with extreme observation properties, which is caused by the beaming effect, expressed by a Doppler factor ( $\delta$ ), in a relativistic jet. Doppler factor is an important parameter in the blazars paradigm to indicate all of the observation properties, and many methods were proposed to estimate its value. In this paper, we present a method following Mattox et al. to calculate the lower limit on $\gamma$ -ray Doppler factor ( $\delta_{\gamma}$ ) for 809 selected Fermi/LAT-detected $\gamma$ -ray blazars by adopting the available $\gamma$ -ray and X-ray data. Our sample included 342 flat-spectrum radio quasars (FSRQs) and 467 BL Lac objects (BL Lacs), out of which 507 sources are compiled with available radio core-dominance parameter (R) from our previous study. Our calculation shows that the average values of the lower limit on $\delta_{\gamma}$ for FSRQs and BL Lacs are $\left\langle\delta_{\gamma}|_{\textrm{FSRQ}}\right\rangle = 6.87 \pm 4.07$ and $\left\langle\delta_{\gamma}|_{\textrm{BL\ Lac}}\right\rangle=4.31 \pm 2.97$ , respectively. We compare and discuss our results with those from the literature. We found that the derived lower limit on $\delta_{\gamma}$ for some sources is higher than that from the radio estimation, which could be possibly explained by the jet bending within those blazars. Our results also suggest that the $\gamma$ -ray and radio regions perhaps share the same relativistic effects. The $\gamma$ -ray Doppler factor has been found to be correlated with both the $\gamma$ -ray luminosity and core-dominance parameter, implying that the jet is possibly continuous in the $\gamma$ -ray bands, and R is perhaps an indicator for a beaming effect.

impact of an extreme observation in a paired samples design

The effect of systematically altering the value of a single observation within a paired differences design is considered. A paradox is observed for the paired samples t-test, where increasing the value of an observation in the direction of the true mean difference results in a higher p-value. Using simulation, deviations from robustness of the paired samples t-test is demonstrated, and is contrasted with Yuen's paired samples t-test and the Wilcoxon signed rank sum test.

PERBANDINGAN INTERPOLASI SPASIAL DENGAN METODE ORDINARY DAN ROBUST KRIGING PADA DATA SPASIAL BERPENCILAN (Studi Kasus: Curah Hujan di Kabupaten Karangasem)

Kriging as optimal spatial interpolation can produce less precise predictive value if there are outliers among the data. Outliers defined as extreme observation value of the other observation values that may be caused by faulty record keeping, improper calibration equipment or other posibbilities. Development of Ordinary Kriging method is Robust Kriging which transforms weight of clasic variogram thus become variogram that robust to outlier. The spatial data that used in this research is the spatial data that contains outliers and meet the assumptions of Ordinary Kriging. The analysis showed that the estimation value of Ordinary Kriging and Robust Kriging method is not much different in terms of Mean Absolute Deviation values which generated by both methods. An increase value of Mean Absolute Deviation on Robust Kriging estimation does not indicate that the Ordinary Kriging method is more precise than Robust Kriging method in the rainfall estimates of Amlapura control point remind that Robust Kriging does not eliminate the data of observation such as the Ordinary Kriging method. In general, Ordinary Kriging and Robust Kriging method can estimate the rainfall value of Amlapura control point quite well although it is not able to cover the changes in rainfall value that occurs due to the behavior geographic data.