论文标题
银河系中的热气和Simba中的簇中的X射线排放
X-ray Emission From Hot Gas in Galaxy Groups and Clusters in Simba
论文作者
论文摘要
我们检查了Simba Galaxy形成模拟中的X射线缩放关系（$ M_ {500}> 10^{12.3} M_ \ ODOT $）。 The X-ray weighted luminosity, $L_X$ vs. $M_{500}$ has power-law slopes $\approx\frac{5}{3}$ and $\approx\frac{8}{3}$ above and below $10^{13.5} M_{\odot}$, deviating from the self-similarity increasingly to low masses. $ t_x-m_ {500} $在此质量上方是自相似的，并且在其下方略浅。将Simba与观察到的$ T_X $ scalings进行比较，我们发现$ l_x $，$ l_x $ - 加权[fe/h]，并且入口处为$ 0.1 r_ {200} $（$ s_ {0.1} $）和$ r_ {500} $（$ s_ {500} $）合理地匹配了所有匹配。 $ s_ {500} -t_x $与自相似的期望一致，但是$ s_ {0.1} -t_x $在较低$ t_x $下是较浅的，这表明，从郊区的重力冲击到较小的小组的非重力反馈的供热的主要形式。 Simba匹配$ L_X $与中央星系恒星质量$ M _*$的观察值，预测了恒星形成星系具有更高$ L_X（M _*）$的其他趋势。 $ M_ {500}> 10^{14} m_ \ odot $ HALOS显示$ \ sim 0.1R_ {200} $ core的电子密度配置文件，但在较低的群众中，所有radii均均为平面。 $ t_x $ profiles是$ m_ {500} <10^{13} m _ {\ odot} $的平面，并且越来越多地以质量达到中心峰值。最高和最低的质量晕圈的最高和最低质量晕圈的熵轮廓在中央凹陷，但中间质量晕圈的凹陷处是$ s _ {\ rm core} \ oft200-400 $ kev cm $^2 $。 Simba的[Fe/H]配置文件与核心中的观测值相匹配，但在较大的半径上过度预测，表明金属分布过多。我们表明，Simba的双极喷射AGN反馈最负责越来越多地撤离下部质量光环，从而抑制了核心密度并提高核心熵以提高与X射线缩放关系的一致性。
We examine X-ray scaling relations for massive halos ($M_{500}>10^{12.3}M_\odot$) in the Simba galaxy formation simulation. The X-ray weighted luminosity, $L_X$ vs. $M_{500}$ has power-law slopes $\approx\frac{5}{3}$ and $\approx\frac{8}{3}$ above and below $10^{13.5} M_{\odot}$, deviating from the self-similarity increasingly to low masses. $T_X-M_{500}$ is self-similar above this mass, and slightly shallower below it. Comparing Simba to observed $T_X$ scalings, we find that $L_X$, $L_X$-weighted [Fe/H], and entropies at $0.1 R_{200}$ ($S_{0.1}$) and $R_{500}$ ($S_{500}$) all match reasonably well. $S_{500}-T_X$ is consistent with self-similar expectations, but $S_{0.1}-T_X$ is shallower at lower $T_X$, suggesting the dominant form of heating moves from gravitational shocks in the outskirts to non-gravitational feedback in the cores of smaller groups. Simba matches observations of $L_X$ versus central galaxy stellar mass $M_*$, predicting the additional trend that star-forming galaxies have higher $L_X(M_*)$. The electron density profiles for $M_{500}>10^{14}M_\odot$ halos show a $\sim 0.1R_{200}$ core, but at lower masses the profiles are flat at all radii. $T_X$ profiles are flat for $M_{500}<10^{13}M_{\odot}$, and increasingly centrally peaked with mass. The resulting entropy profiles are centrally depressed for the highest and lowest mass halos but flatter for intermediate-mass halos, with $S_{\rm core}\approx200-400$ keV cm$^2$. Simba's [Fe/H] profile matches observations in the core but over-predicts at larger radii, suggesting overly widespread metal distribution. We show that Simba's bipolar jet AGN feedback is most responsible for increasingly evacuating lower-mass halos, thereby suppressing core densities and raising core entropies to improve agreement with X-ray scaling relations.
