Figure 3 · point file
Zhang+24 M31-mass stack at 20 kpc:数据点推理
Zhang+24 M31-mass stack at 20 kpc: point reasoning
zhang2024_m31_mass_nominal_20kpc
Figure 3最终值
Final Figure 3 value
0.8284536870.828453687 – 0.82845368710−15 erg cm−2 s−1 arcmin−2
population template,不是M31本身测量或formal local prior。
A population template, not an M31 measurement or formal local prior.
原文输入量
Native published input
M31-mass external-galaxy stack的20 kpc intrinsic 0.5-2.0 luminosity surface density。
Intrinsic 0.5-2.0 luminosity surface density at 20 kpc from the M31-mass external-galaxy stack.
转换链
Conversion chain
选择M31-mass bin、在20 kpc评价published median beta profile,再做distance-cancel angular conversion和v19 APEC absorption bridge。
Select the M31-mass bin, evaluate the published median beta profile at 20 kpc, then apply the distance-cancel angular conversion and v19 APEC absorption bridge.
- 不按连续mass relation缩放:直接选择原文11.0<log(M*/Msun)<11.25的M31-mass central-galaxy stack。Do not apply a continuous mass scaling relation: directly select the paper's M31-mass central-galaxy stack at 11.0<log(M*/Msun)<11.25.
- 采用Table 4 M31-mass median log S_X0=37.1、r_c=4 kpc、beta=0.37,在physical R=20 kpc评价projected beta profile,得到1.7253e36 erg s^-1 kpc^-2。Use the Table 4 M31-mass medians log S_X0=37.1, r_c=4 kpc, and beta=0.37 and evaluate the projected beta profile at physical R=20 kpc, giving 1.7253e36 erg s^-1 kpc^-2.
S_X(20)=10^37.1[1+(20/4)^2]^(-3×0.37+1/2) - 利用surface-brightness distance cancellation,把luminosity surface density除以4pi kpc_cm^2并乘arcmin^2/sr,再乘v19 absorbed/intrinsic ratio 0.678988916,得到Figure 3值0.828454。Use surface-brightness distance cancellation: divide luminosity surface density by 4pi kpc_cm^2, multiply by arcmin^2/sr, and apply the v19 absorbed/intrinsic ratio 0.678988916 to obtain the Figure 3 value 0.828454.
S_fig=S_L×Ω_arcmin2/(4π kpc_cm²)×0.678988916/10^-15
新增假设与边界
Added assumptions and boundaries
- 单一thermal template代替stack的温度/金属丰度分布。One thermal template substitutes for the stack's temperature/metallicity distribution.