Figure 3 · study file
The warm-hot circumgalactic medium of the Milky Way as seen by eROSITA
Locatelli et al.用eROSITA O VIII line map拟合Milky-Way warm-hot CGM的spherical-halo与exponential-disk几何。Figure 3的橙线不是论文表中的broadband flux，而是把named reference Combined beta=0.5 geometry转移到十四条M31视线。
Locatelli et al. fit spherical-halo and exponential-disk geometries to an eROSITA O VIII line map of the Milky-Way warm-hot CGM. The orange Figure 3 line is not a tabulated broadband flux; it transfers the named reference Combined beta=0.5 geometry through fourteen M31 sightlines.
DOI 10.1051/0004-6361/202347061
Source snapshot: arXiv:2310.10715v1 · 2026-07-15T10:49:33ZSHA-256 4a9220468bfabcf9eeeb464c7f93d9b87bf8f647798efc42a0fd4a5007537a6f
eROSITA eRASS1的eROSITA_DE western Galactic half O VIII narrow-band map；相关原始observable是0.614-0.694 keV line-band photon intensity，80 eV窗口近似eROSITA能量分辨率。
An O VIII narrow-band map of the eROSITA_DE western Galactic half from eROSITA eRASS1. The native observable is photon intensity in 0.614-0.694 keV; the 80 eV window approximates the eROSITA energy resolution.
论文拟合western half（约180<l<360 deg）的mid/high-|b| MW line map，并mask eROSITA bubbles及明亮extended structures；M31位于l约121、b约-21.6 deg，明确在native map域外。本项目从太阳内部位置把reference geometry外推到十四个M31 XMM pointing centers。
The paper fits the mid/high-|b| Milky-Way line map in the western half (roughly 180<l<360 deg), masking the eROSITA bubbles and bright extended structures. M31 at about l=121, b=-21.6 deg is explicitly outside that native map domain. This project extrapolates the reference geometry from the internal Solar position through fourteen M31 XMM pointing centers.
native fit约束O VIII line intensity及其空间形态，不直接测量absorbed 0.5-2.0 keV energy surface brightness。
The native fit constrains O VIII line intensity and its spatial morphology, not absorbed 0.5-2.0 keV energy surface brightness.
Figure 3采用论文指定的reference Combined beta=0.5：spherical n_h=C r^(-3 beta)加exponential n_d=n0 exp(-R/Rh) exp(-|z|/zh)，参数beta=0.5、C=0.046、n0=0.032 cm-3、Rh=6.2 kpc、zh=1.1 kpc、kT=0.15 keV、Z=0.1。发射实现为n_h^2+n_d^2，没有cross term。论文Eq. (7)的交叉项漏印path-length s而量纲不成立；项目按Miller & Bregman上游公式保留s。
Figure 3 uses the paper-designated reference Combined beta=0.5 model: spherical n_h=C r^(-3 beta) plus exponential n_d=n0 exp(-R/Rh) exp(-|z|/zh), with beta=0.5, C=0.046, n0=0.032 cm-3, Rh=6.2 kpc, zh=1.1 kpc, kT=0.15 keV, and Z=0.1. The emission implementation is n_h^2+n_d^2 without a cross term. The cross term printed in Eq. (7) omits the path-length s and is dimensionally invalid; the project retains s following the upstream Miller & Bregman formula.
paper result是O VIII-constrained geometry及Table 1参数族。Table 1的single spherical fit给beta=0.26+/-0.01，而Sect. 4.3正文写beta=0.23；两种正式来源保留这一内部不一致，本registry采用Table 1值并明确记录冲突。论文没有发表M31方向absorbed broadband值，也没有发表足以构造joint posterior的参数covariance。
The paper result is an O VIII-constrained geometry and the Table 1 parameter family. Table 1 gives beta=0.26+/-0.01 for the single spherical fit, whereas Sect. 4.3 states beta=0.23; both formal sources retain this internal discrepancy, so the registry adopts the Table 1 value while recording the conflict. The paper does not publish absorbed broadband values toward M31 or the parameter covariance required for a joint posterior.
先积分n_h^2+n_d^2得到十四场EM和intrinsic O VIII 4.14-4.56 L.U.；用80 eV FWHM Gaussian匹配原map line-band emissivity；固定该O VIII normalization并转换到Z=0.3 target APEC，再用每场HI4PI full-screen phabs得到absorbed 0.5-2.0。与observed all-field相同weights给1.290382，footprint 1.157655-1.341463，North/South 1.295557/1.213445。
Integrating n_h^2+n_d^2 first gives fourteen-field EMs and intrinsic O VIII intensities of 4.14-4.56 L.U. An 80 eV FWHM Gaussian matches the map's line-band emissivity treatment. Holding that O VIII normalization fixed, the transfer uses a Z=0.3 target APEC model and field-specific HI4PI full-screen phabs to obtain absorbed 0.5-2.0. Using the same weights as the observed all-field total gives 1.290382, footprint 1.157655-1.341463, and North/South 1.295557/1.213445.
M31方向处于western-half training map域外；line-to-broadband、target abundance、full-screen absorption和field weighting也均是本项目transfer。0.934302-1.574700只由published marginal errors作diagonal sensitivity propagation，不是credible interval。1.290超过observed total 0.965约0.326，表示named model+conversion tension，不是负M31 emission。
The M31 direction lies outside the western-half training map. The line-to-broadband bridge, target abundance, full-screen absorption, and field weighting are also project transfers. The 0.934302-1.574700 range is diagonal sensitivity propagation from published marginal errors, not a credible interval. The 1.290 value exceeds the observed total 0.965 by about 0.326, indicating named model-plus-conversion tension rather than negative M31 emission.
1.290382 [1.157655, 1.341463]
ledger row的figure_central是side-balanced 1.255；Figure 3与all-field total配对的实心线另采用all-field estimator 1.290。
The ledger row's figure_central is the side-balanced 1.255; the solid Figure 3 line paired with the all-field total instead uses the separate all-field estimator 1.290.
| Location | Claim | Link |
|---|---|---|
| Table 1 | Reference Combined beta=0.5 parameters and marginal errors. | primary source |
| Model and emissivity sections | O VIII line-map observable, density geometries, temperature/abundance, and reference-model identity. | primary source |
| Version-of-record PDF | Figure/table identity and O VIII map processing used by the response-matched transfer. | primary source |