目录Contents
术语表与阅读清单Glossary and reading list
术语表Glossary
| 术语Term | 解释Meaning |
|---|---|
| CGMCGM | circumgalactic medium，星系周介质：星系晕中约 10⁶–10⁷ K 的稀薄电离气体，藏有大部分「失踪重子」。circumgalactic medium: thin ionised gas at ~10⁶–10⁷ K in a galaxy's halo, holding most of the "missing baryons". |
| CGMsumCGMsum | 项目记号：一条视线上的冷热总和 S_tot = S_M31 + S_MW（可选第三项 S_LG）。v19 里名为 MWhalo 的共享分量测的就是它。project notation: the cool line-of-sight sum S_tot = S_M31 + S_MW (optional third term S_LG). In v19 the shared component named MWhalo measures exactly this. |
| LHBLHB | Local Hot Bubble，本地热泡：太阳周围约 0.1 keV 的热气体空腔，是所有软 X 射线视线的近端前景。Local Hot Bubble: a cavity of ~0.1 keV hot gas around the Sun, the near foreground of every soft X-ray sightline. |
| MW haloMW halo | 银河系热晕：银河系自身的百万度气体，M31 方向的前景，与 M31 CGM 谱形几乎相同（I006）。the Milky Way hot halo: the MW's own million-degree gas, the foreground toward M31, spectrally almost identical to the M31 CGM (I006). |
| LHB vs Local Hot BridgeLHB vs Local Hot Bridge | 注意歧义：LHB 一般指太阳邻域的泡；Local Hot Bridge（Qu+2021）指银河系与 M31 之间桥状的群内热气体（kT≈0.189 keV）。两者缩写像但完全不同——本站写全称区分。mind the ambiguity: LHB usually means the solar-neighbourhood bubble; the Local Hot Bridge (Qu+2021) means bridge-shaped intragroup hot gas between the MW and M31 (kT≈0.189 keV). Similar abbreviations, completely different things — this site spells both out. |
| CXBCXB | cosmic X-ray background：远处未分辨 AGN/星系的幂律背景（Γ≈1.46）。cosmic X-ray background: the power-law background (Γ≈1.46) of distant unresolved AGN/galaxies. |
| QPBQPB | quiescent particle background：粒子在 CCD 里沉积电荷形成的稳定背景，用视场外角区事件估计并直接减除。quiescent particle background: the steady background from particles depositing charge in the CCD, estimated from out-of-field corner events and subtracted. |
| SPSP | soft protons，软质子：被磁层聚焦、随时耀发的质子，逐谱用折断幂律拟合。soft protons: protons focused by the magnetosphere, flaring on all timescales, fitted per spectrum as a broken power law. |
| SWCXSWCX | solar-wind charge exchange：太阳风离子与中性氢的电荷交换线发射，随太阳风强度变化（E014 已检验并排除它作为外 NW 超出的解释，D49）。solar-wind charge exchange: line emission from charge exchange between solar-wind ions and neutral hydrogen, varying with the solar wind (E014 tested and excluded it as the explanation for the outer-NW excess, D49). |
| ARF / RMFARF / RMF | effective area / response matrix：把光子流量变成计数谱的两件标定文件（physics.html §1 有算例）。the effective area / response matrix: the two calibration files that turn photon flux into a count spectrum (physics.html §1 has a worked example). |
| APECAPEC | 碰撞电离平衡等离子体发射模型；参数 kT（温度）、Z（丰度）、norm（∝ 发射量/4πD²）。a collisional-ionisation-equilibrium plasma emission model; parameters kT, Z, norm (∝ emission measure / 4πD²). |
| N_HN_H | 中性氢柱密度（1e22 cm⁻²）；本项目用 HI4PI 逐指向 15 arcmin 孔径的原子 N_HI。neutral-hydrogen column (1e22 cm⁻²); this project uses the per-pointing 15-arcmin aperture atomic N_HI from HI4PI. |
| HI4PIHI4PI | 全天 21 cm 中性氢巡天，分辨率 16.2 arcmin，N_H 的来源图。the all-sky 21-cm neutral-hydrogen survey, 16.2 arcmin resolution, the source map for N_H. |
| RASSRASS | ROSAT All-Sky Survey：1990–91 年的全天软 X 射线巡天；R1–R7 能带，R4+R5（≈0.44–1.21 keV）与本项目能带最接近。the ROSAT All-Sky Survey: the 1990–91 all-sky soft X-ray survey; bands R1–R7, with R4+R5 (≈0.44–1.21 keV) closest to this project's band. |
| eROSITAeROSITA | ROSAT 的现代继任者（eRASS 巡天）；Zhang+2024 的星系叠加剖面与 Locatelli+2024 的银河系模型都来自它。ROSAT's modern successor (the eRASS survey); both the Zhang+2024 galaxy stack profile and the Locatelli+2024 MW model come from it. |
| β 模型model | S(r) = S₀(1+(r/r_c)²)^(−3β+1/2)：等温球投影亮度的标准参数化。S(r) = S₀(1+(r/r_c)²)^(−3β+1/2): the standard parameterisation of an isothermal sphere's projected brightness (S₀ is the central value). |
| profile likelihoodprofile likelihood | 轮廓似然：固定目标参数、重优化其余参数得到的统计量曲线；区间用 Δstat 阈值（1 参数 68%: Δ=1；单侧 95%: Δ=2.71）。fix the parameter of interest, re-optimise the rest, and read intervals off the statistic curve (1 free parameter: Δ=1 for 68%; Δ=2.71 for one-sided 95%). |
| Δχ² / ΔstatΔχ² / Δstat | 两个模型的统计量之差；嵌套模型差 1 参数时 Δχ²≈1 表示无信息，Δχ²=6.2≈2.5σ。the statistic difference between two models; for nested models differing by 1 parameter, Δχ²≈1 means no information and Δχ²=6.2 is about 2.5σ. |
来源：各条目对应的认知文件（CGMsum I009/I012；LHB/Local Hot Bridge 歧义 I011 与 Qu+2021；SWCX E014 与 D49；N_H/HI4PI E003；RASS R1–R7 E010 BRIEF；β 模型与 Δstat 见 physics.html）。
Source: the cognition file behind each entry (CGMsum I009/I012; the LHB/Local Hot Bridge ambiguity I011 and Qu+2021; SWCX E014 and D49; N_H/HI4PI E003; RASS R1–R7 the E010 BRIEF; beta model and Δstat on physics.html).
阅读清单（每篇一行：为什么重要）Reading list (one line each: why it matters)
- Kavanagh et al. 2020（DOI 10.1051/0004-6361/201937008）：在北盘深场的盘旁背景区测得 0.17–0.18 keV 分量并明确把它建模为银河系+M31+IGM 之和——直接先例；但 D48 更正：其区域不是 10–31 kpc 晕视线，不是本测量的先例艺术。Kavanagh et al. 2020 (DOI 10.1051/0004-6361/201937008): measured a 0.17–0.18 keV component in disc-adjacent background regions of their northern-disc deep fields and explicitly modelled it as Galaxy+M31+IGM — a direct precedent; but the D48 correction: those regions are not 10–31 kpc halo sightlines and are not prior art for this measurement.
- Qu et al. 2021（DOI 10.3847/1538-4357/abc9b9）：M31 方向约 20° 的 O VII/O VIII+SZ 增强，kT≈0.189 keV，解释为可能的 Local Hot Bridge——本项目第三分量场景的来源。Qu et al. 2021 (DOI 10.3847/1538-4357/abc9b9): an approximately 20-degree O VII/O VIII+SZ enhancement toward M31, kT≈0.189 keV, interpreted as a possible Local Hot Bridge — the origin of this project's third-component scenario.
- Locatelli et al. 2024：eRASS 西半球的银河系扩散模型；投影到 M31 足迹给 1.290，比测量值 0.965 高——本项目的「模型紧张」。注意它是域外外推（M31 在东半球 l≈121°）。Locatelli et al. 2024: the eRASS western-hemisphere MW diffuse model; projected to the M31 footprint it gives 1.290, above the measured 0.965 — this project's "model tension". Mind that it is an outside-map extrapolation (M31 is in the eastern hemisphere, l≈121°).
- Ueda et al. 2022（DOI 10.1093/pasj/psac077）：Suzaku 银河系盘密度模型（n_e0=3.4e-3 cm⁻³）；投影到 14 场给 0.312——域内方向性条件模型。Ueda et al. 2022 (DOI 10.1093/pasj/psac077): the Suzaku MW disc density model (n_e0=3.4e-3 cm⁻³); projected to the 14 fields it gives 0.312 — an in-domain directional conditional model.
- Kaaret et al. 2020（HaloSat）：73 个高银纬场的银河系晕测量；外推到 M31 给 0.565——但 14 场全在其拟合域（b<−30°）之外，仅作补充外推。Kaaret et al. 2020 (HaloSat): MW halo measurements over 73 high-latitude fields; extrapolated to M31 it gives 0.565 — but all 14 fields lie outside its fit domain (b<−30°); a supplemental extrapolation only.
- Zhang et al. 2024（DOI 10.1051/0004-6361/202449412）：eRASS M31 质量星系叠加剖面（r_c=4 kpc，β=0.37）；20 kpc 转移值 0.828——与本项目上限（MW 常数版 ≤0.05–0.12，D49 后默认）相差 7–17 倍的核心比较。Zhang et al. 2024 (DOI 10.1051/0004-6361/202449412): the eRASS M31-mass galaxy stack profile (r_c=4 kpc, β=0.37); the 20-kpc transferred value 0.828 — the core comparison against this project's limit (MW-constant version ≤0.05–0.12, the default after D49), a factor 7–17 apart.
- Henley & Shelton 2013（DOI 10.1088/0004-637X/773/2/92）：110 条高银纬 XMM 视线的银河系晕统计（中位 0.385，转换后）；M31 银纬在样本外，仅作人群背景。Henley & Shelton 2013 (DOI 10.1088/0004-637X/773/2/92): MW halo statistics over 110 high-latitude XMM sightlines (median 0.385 after conversion); M31's latitude is outside the sample — population context only.
- New-ANGELS I（arXiv:2306.10113）：M31 X 射线源表——本项目的源掩膜规则来源（D48）。New-ANGELS I (arXiv:2306.10113): the M31 X-ray source catalogue — the source of this project's source-mask rule (D48).
- New-ANGELS II（arXiv:2511.05856）：M31 X 射线源光度函数——扣除极限下未解源。New-ANGELS II (arXiv:2511.05856): the M31 X-ray luminosity function — for subtracting unresolved sources below the limit.
- Wang et al. 2026（arXiv:2608.10088）：M31 吸收线巡天——未来用紫外吸收联合解释的接口。Wang et al. 2026 (arXiv:2608.10088): the M31 absorption survey — the future interface for joint interpretation with UV absorption.
来源：Kavanagh/Qu/Henley/Ueda/Zhang 的 DOI 与结论来自 cognition-os/insights/I011 与 I017；Locatelli/HaloSat/eFEDS 数值来自 02_CURRENT_QUESTION.md（D42–D46 块）与 paper_apj_v19_cgmsum_draft/data/m31_cgmsum_conditional_prior_ledger.csv；New-ANGELS I/II 与 Wang 2026 来自 04_DECISION_LOG.md D48。
Source: the DOIs and findings for Kavanagh/Qu/Henley/Ueda/Zhang from cognition-os/insights/I011 and I017; the Locatelli/HaloSat/eFEDS numbers from 02_CURRENT_QUESTION.md (D42–D46 block) and paper_apj_v19_cgmsum_draft/data/m31_cgmsum_conditional_prior_ledger.csv; New-ANGELS I/II and Wang 2026 from 04_DECISION_LOG.md D48.
公开镜像Public mirrors
- 论文草稿公开镜像m31cgm-cgmsum-apj-draft.pages.dev — 16 页 PDF + 双语 HTML16-page PDF plus bilingual HTML
- MW/M31 剖面探索器m31cgm-mw-m31-profile-explorer.pages.dev — Figure 3 与文献图谱Figure 3 and the literature atlas