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تسجيل مستخدم جديدInvestigating $gamma$-ray halos around three HAWC bright sources in Fermi-LAT data
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Numerous extended sources around Galactic pulsars have shown significant $gamma$-ray emission from GeV to TeV energies, revealing hundreds of TeV energy electrons scattering off of the underlying photon fields through inverse Compton scattering (ICS). HAWC TeV gamma-ray observations of few-degree extended emission around the pulsars Geminga and Monogem, and LAT GeV emission around Geminga, suggest that systems older than 10-100 kyr have multi-TeV $e^pm$ propagating beyond the SNR-PWN system into the interstellar medium. Following the discovery of few $gamma$-ray sources by HAWC at energies E$>100$ TeV, we investigate the presence of an extended $gamma$-ray emission in Fermi-LAT data around the three brightest sources detected by HAWC up to 100 TeV. We find an extended emission of $theta_{68} = 1.00^{+0.05}_{-0.07}$ deg around eHWC J1825-134 and $theta_{68} = 0.71pm0.10$ deg eHWC J1907+063. The analysis with ICS templates on Fermi-LAT data point to diffusion coefficient values which are significantly lower than the average Galactic one. When studied along with HAWC data, the $gamma$-ray Fermi-LAT data provide invaluable insight into the very high-energy electron and positron parent populations.
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