论文标题
宇宙大规模结构中的热和重力密度
The thermal and gravitational energy densities in the large-scale structure of the Universe
论文作者
论文摘要
随着宇宙结构的形式，物质密度波动在重力上崩溃，重型物质被冲击加热和热效。因此，我们期望折叠光环的平均重力势能密度，$ω__{w}^{\ rm晕halo} $与巴属的平均热能密度，$ω__{\ rm th} $之间的连接。这些数量可以使用两个根本不同的估计值获得：我们使用halo模型的理论框架计算$ω_{w}^{\ rm halo} $，该模型是由暗物质统计驱动的，并测量$ω_ {\ rm th} $，使用Sunyaev-Zeldovich（sz）效果效果。首先，我们在目前得出，约有$ω__{w}^{\ rm halo} $的90％来自大型卤素，$ m> 10^{13} \，m_ \ odot $。然后，使用我们对SZ背景的测量值，我们发现$ω_ {\ rm th} $占BARYONS的80％的BARYONS可用于HAROS $ z \ lyssim 0.5 $的气管的动能。这会限制非热压的量，例如，由于质量积聚产生的散装和湍流气体，约为$ω_ {\ rm non-th} \ simeq 0.4 \ simeq 0.4 \ times 10^{ - 8} $ $ z = 0 $。
As cosmic structures form, matter density fluctuations collapse gravitationally and baryonic matter is shock-heated and thermalized. We therefore expect a connection between the mean gravitational potential energy density of collapsed halos, $Ω_{W}^{\rm halo}$, and the mean thermal energy density of baryons, $Ω_{\rm th}$. These quantities can be obtained using two fundamentally different estimates: we compute $Ω_{W}^{\rm halo}$ using the theoretical framework of the halo model which is driven by dark matter statistics, and measure $Ω_{\rm th}$ using the Sunyaev-Zeldovich (SZ) effect which probes the mean thermal pressure of baryons. First, we derive that, at the present time, about 90% of $Ω_{W}^{\rm halo}$ originates from massive halos with $M>10^{13}\,M_\odot$. Then, using our measurements of the SZ background, we find that $Ω_{\rm th}$ accounts for about 80% of the kinetic energy of the baryons available for pressure in halos at $z\lesssim 0.5$. This constrains the amount of non-thermal pressure, e.g., due to bulk and turbulent gas motion sourced by mass accretion, to be about $Ω_{\rm non-th}\simeq 0.4\times 10^{-8}$ at $z=0$.
