论文标题
搜索47图卡纳和欧米茄半人马座的歼灭暗物质
A Search for Annihilating Dark Matter in 47 Tucanae and Omega Centauri
论文作者
论文摘要
银河球状簇47 tuc和欧米茄群的合理形态场景是，它们是潮汐剥离的矮星系的残余物，在这种情况下，它们很可能保留了一小部分暗物质岩心。在这项研究中，我们使用XX/$ E^+E^ - $通道在Parkes望远镜（Murriyang）上使用了超宽的带接收器将外来光暗物质颗粒颗粒（X）的an灭速率放在上限上。这是以前用于在银河中心搜索PS的技术的扩展。但是，通过在多线频率下堆叠光谱数据，我们能够提高灵敏度。我们的测量结果导致3-磁通量密度（重组率）上限为1.7 mjy（1.4x10 $^{43} $ s $ s $^{ - 1} $）和0.8 mjy（1.1x10 $^{43} $ s $ s $ s $^{ - 1} $），用于47 tuc and ome ome ga cen，分别为47 tuc和ome omega cen cen cen con。 Within the Parkes beam at the cluster distances, which varies from 10 to 23 pc depending on the frequency of the recombination line, we calculate upper limits to the dark matter mass and rms dark matter density of <1.2-1.3x10$^5$ fn$^{-0.5}$ (mX/MeV c$^{-2}$) solar masses and <48-54 fn$^{-0.5}$ （mx/mev c $^{ - 2} $）太阳能群体PC $^{ - 3} $，其中Fn = rn/rp是PS重组过渡与nih灭的比率，估计为0.01。 Omega CEN的无线电限制表明，对于基准的深色/发光质量比为0.05，除非横截面<7.9x10 $^{ - 28} $（MX/MEV C $^{ - 2} $）由于集群的紧凑性和接近性，档案511-KEV测量表明，比CMB各向异性所允许的更紧密的限制，<8.6x10 $^{ - 31} $（MX/MEV C $^{ - 2}} $^2 $ CM $ CM $ CM $ CM $^3 $ s $ s $ s $^{-1} $。我们的重组率限制了银河系以前的无线电限制。
A plausible formation scenario for the Galactic globular clusters 47 Tuc and Omega Cen is that they are tidally stripped remnants of dwarf galaxies, in which case they are likely to have retained a fraction of their dark matter cores. In this study, we have used the ultra-wide band receiver on the Parkes telescope (Murriyang) to place upper limits on the annihilation rate of exotic Light Dark Matter particles (X) via the XX/$e^+e^-$ channel using measurements of the recombination rate of positronium (Ps). This is an extension of a technique previously used to search for Ps in the Galactic Centre. However, by stacking of spectral data at multiple line frequencies, we have been able to improve sensitivity. Our measurements have resulted in 3-sigma flux density (recombination rate) upper limits of 1.7 mJy (1.4x10$^{43}$ s$^{-1}$) and 0.8 mJy (1.1x10$^{43}$ s$^{-1}$) for 47 Tuc and Omega Cen, respectively. Within the Parkes beam at the cluster distances, which varies from 10 to 23 pc depending on the frequency of the recombination line, we calculate upper limits to the dark matter mass and rms dark matter density of <1.2-1.3x10$^5$ fn$^{-0.5}$ (mX/MeV c$^{-2}$) solar masses and <48-54 fn$^{-0.5}$ (mX/MeV c$^{-2}$) solar masses pc$^{-3}$ for the clusters, where fn=Rn/Rp is the ratio of Ps recombination transitions to annihilations, estimated to be 0.01. The radio limits for Omega Cen suggest that, for a fiducial dark/luminous mass ratio of 0.05, any contribution from Light Dark Matter is small unless the cross section <7.9x10$^{-28}$ (mX/MeV c$^{-2}$)$^2$ cm$^3$ s$^{-1}$. Owing to the compactness and proximity of the clusters, archival 511-keV measurements suggest even tighter limits than permitted by CMB anisotropies, <8.6x10$^{-31}$ (mX/MeV c$^{-2}$)$^2$ cm$^3$ s$^{-1}$. Our recombination rate limits substantially improve on previous radio limits for the Milky Way.
