论文标题
用热气晕限制银河系质量
Constraining the Milky Way Mass with Its Hot Gaseous Halo
论文作者
论文摘要
我们提出了一种新的方法来限制银河系（MW）质量$ m _ {\ rm vir} $，并以其电晕温度观察。对于给定的电晕密度曲线，假设具有非热压支持的广义平衡模型，则可以得出其温度分布。虽然派生的温度曲线大大降低了半径，但X射线发射加权的平均温度最敏感地取决于$ M _ {\ rm vir} $，对不同的视线线非常均匀，与X射线观测一致。对于Navarro-frenk-White（NFW）总物质分布，应核心电晕密度曲线，并且我们约束$ M _ {\ rm vir} =（1.19 $ - $ 2.95）\ times 10^{12} M _ {\ rm Sun} $。对于由NFW暗物质概况和中央巴元的贡献的总物质分布，Corona密度曲线应为cuspy和$ m _ {\ rm vir，dm} =（1.34 $ - $ 5.44）\ times 10^{12} {12} m _ {\ rm sun} $。非热压力支持会导致更高的$ m _ {\ rm vir} $的值，而如果电晕在向外加速，则可能有可能较低的MW质量。该方法与非常大的半径下的总电晕质量，其金属性和温度无关。
We propose a novel method to constrain the Milky Way (MW) mass $M_{\rm vir}$ with its corona temperature observations. For a given corona density profile, one can derive its temperature distribution assuming a generalized equilibrium model with non-thermal pressure support. While the derived temperature profile decreases substantially with radius, the X-ray-emission-weighted average temperature, which depends most sensitively on $M_{\rm vir}$, is quite uniform toward different sight lines, consistent with X-ray observations. For an Navarro-Frenk-White (NFW) total matter distribution, the corona density profile should be cored, and we constrain $M_{\rm vir}=(1.19$ - $2.95) \times 10^{12} M_{\rm sun}$. For a total matter distribution contributed by an NFW dark matter profile and central baryons, the corona density profile should be cuspy and $M_{\rm vir,dm}=(1.34$ - $5.44) \times 10^{12} M_{\rm sun}$. Non-thermal pressure support leads to even higher values of $M_{\rm vir}$, while a lower MW mass may be possible if the corona is accelerating outward. This method is independent of the total corona mass, its metallicity, and temperature at very large radii.
