J-factor estimation of Draco, Sculptor, and Ursa Minor dwarf spheroidal galaxies with the member/foreground mixture model
J-factor estimation of Draco, Sculptor, and Ursa Minor dwarf spheroidal galaxies with the member/foreground mixture model
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DOI：
10.1093/mnras/staa2909
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发表时间：
2020-02
影响因子：
4.8
通讯作者：
Shun-ichi Horigome;Kohei Hayashi;M. Ibe;M. Ishigaki;S. Matsumoto;H. Sugai
中科院分区：
文献类型：
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作者：
Shun-ichi Horigome;Kohei Hayashi;M. Ibe;M. Ishigaki;S. Matsumoto;H. Sugai
矮球状星系是目前宇宙中寻找暗物质的间接探测实验的理想目标。走向强大的预测源自DM湮灭dSphs内的信号通量的量，DM分布以及$J$-因素的dSphs的精确测定是特别重要的。在这项工作中，我们估计天龙座，玉夫座和小熊座dSphs的改进的统计方法，其中前景星和dSphs成员星同时考虑。我们定义的似然函数的方法作为所谓的条件之一，以消除观测恒星数据的采样偏差。这种改进的方法使我们能够估计DM分布和$J$-因素的dSphs直接从观测到的恒星数据污染的前景恒星，而不施加严格的成员资格标准的测量量。
Dwarf spheroidal galaxies (dSphs) are promising targets of indirect detection experiments searching for dark matter (DM) at present universe. Toward robust prediction for the amount of signal flux originating in DM annihilation inside dSphs, a precise determination of DM distributions as well as $J$-factors of the dSphs is particularly important. In this work, we estimate those of Draco, Sculptor, and Ursa Minor dSphs by an improved statistical method in which both foreground stars and dSph member stars are simultaneously taken into account. We define the likelihood function of the method as the so-called conditional one to remove sampling bias of observed stellar data. This improved method enables us to estimate DM distributions and $J$-factors of the dSphs directly from observed stellar data contaminated by foreground stars without imposing stringent membership criteria on the measured quantities.