Study of {gamma}-ray Emission from a Compact Radio Galaxy with the Fermi Large Area Telescope

Study of {gamma}-ray Emission from a Compact Radio Galaxy with the Fermi Large Area Telescope
Tan-Zheng Wu (BIT), Yu-Wei Yu (BIT), Ying-Ying Gan (BIT), Hai-Ming Zhang (NJU), Jin Zhang (BIT)
arXiv:2404.16373v1 Announce Type: new
Abstract: The radio galaxy PKS 1007+142 is classified as a compact steep-spectrum source (CSS) and belongs to the class of young Active Galactic Nuclei (AGNs). In this paper, we investigate the $gamma$-ray emission from this CSS by conducting a comprehensive analysis of the 15 yr Fermi Large Area Telescope (Fermi-LAT) observation data. The Fermi-LAT latest Source Catalog, 4FGL-DR4, includes an unassociated $gamma$-ray source, 4FGL J1010.0+1416, located at 0.24{deg} away from the radio position of PKS 1007+142. Using the 15 yr Fermi-LAT observation data, we re-estimate the best-fit position of the $gamma$-ray source and find that PKS 1007+142 is in close proximity to the $gamma$-ray source and falls within its 68% error circle. Therefore, we conclude that PKS 1007+142 is the most plausible counterpart to the unassociated LAT source with a detection test statistics (TS) $sim$43.4 ($sim 6.6sigma$). PKS 1007+142 exhibits a steep power-law spectrum in the 0.1–300 GeV band, with a photon spectral index ($Gamma_{gamma}$) of $2.86pm0.17$. The average flux in the considered time interval is $rm (2.14pm0.34)times10^{-12} erg cm^{-2} s^{-1}$. Comparing PKS 1007+142 with other $gamma$-ray emitting AGNs in both the $L_{gamma}-Gamma_{gamma}$ and $L_gamma-L_{rm 1.4GHz}$ planes, it shows a softer $gamma$-ray spectrum and lower luminosity compared to other $gamma$-ray emitting CSSs. Furthermore, the possible origins of $gamma$-ray in PKS 1007+142 are also discussed.arXiv:2404.16373v1 Announce Type: new
Abstract: The radio galaxy PKS 1007+142 is classified as a compact steep-spectrum source (CSS) and belongs to the class of young Active Galactic Nuclei (AGNs). In this paper, we investigate the $gamma$-ray emission from this CSS by conducting a comprehensive analysis of the 15 yr Fermi Large Area Telescope (Fermi-LAT) observation data. The Fermi-LAT latest Source Catalog, 4FGL-DR4, includes an unassociated $gamma$-ray source, 4FGL J1010.0+1416, located at 0.24{deg} away from the radio position of PKS 1007+142. Using the 15 yr Fermi-LAT observation data, we re-estimate the best-fit position of the $gamma$-ray source and find that PKS 1007+142 is in close proximity to the $gamma$-ray source and falls within its 68% error circle. Therefore, we conclude that PKS 1007+142 is the most plausible counterpart to the unassociated LAT source with a detection test statistics (TS) $sim$43.4 ($sim 6.6sigma$). PKS 1007+142 exhibits a steep power-law spectrum in the 0.1–300 GeV band, with a photon spectral index ($Gamma_{gamma}$) of $2.86pm0.17$. The average flux in the considered time interval is $rm (2.14pm0.34)times10^{-12} erg cm^{-2} s^{-1}$. Comparing PKS 1007+142 with other $gamma$-ray emitting AGNs in both the $L_{gamma}-Gamma_{gamma}$ and $L_gamma-L_{rm 1.4GHz}$ planes, it shows a softer $gamma$-ray spectrum and lower luminosity compared to other $gamma$-ray emitting CSSs. Furthermore, the possible origins of $gamma$-ray in PKS 1007+142 are also discussed.