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arXiv · 1611.05565

3FGL J1924.8-1034 : A Spatially-Extended Stable Unidentified GeV Source?

Zi-Qing Xia·Kai-Kai Duan·Shang Li·Yun-Feng Liang·Zhao-Qiang Shen·Chuan Yue·Yuan-Peng Wang·Qiang Yuan·Yi-Zhong Fan·Jian Wu·Jin Chang
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Abstract

Milky Way-like galaxies are predicted to host a very large number of dark matter subhalos. Some massive and nearby subhalos could generate detectable gamma-rays, appearing as unidentified, spatially-extended and stable gamma-ray sources. We search for such sources in the third Fermi Large Area Telescope source List (3FGL) and report the identification of a new candidate, 3FGL J1924.8-1034. With the Fermi-LAT Pass 8 data, we find that 3FGL J1924.8-1034 is spatially-extended at a high confidence level of $5.4\sigma$, with a best-fit extension radius of $\sim0.15^{\circ}$. No significant variability has been found and its gamma-ray spectrum is well fitted by the dark matter annihilation into $b\bar{b}$ with a mass of $\sim 43$ GeV. All these facts make 3FGL J1924.8-1034 a possible dark matter subhalo candidate. However, due to the limited angular resolution, the possibility of that the spatial extension of 3FGL J1924.8-1034 is caused by the contamination from the other un-resolved point source can not be ruled out.

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Zi-Qing Xia, Kai-Kai Duan, Shang Li, Yun-Feng Liang, Zhao-Qiang Shen, Chuan Yue, Yuan-Peng Wang, Qiang Yuan, Yi-Zhong Fan, Jian Wu, Jin Chang. 2016-11-17. 3FGL J1924.8-1034 : A Spatially-Extended Stable Unidentified GeV Source?. https://doi.org/10.1103/physrevd.95.102001

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