# E08 · 13 June 1998 · observational-association control

**E08 R138 RESULT: ASSOCIATION CONTROL RESOLVED; OUTER-FRONT MHD FAMILY NOT IDENTIFIED.**

The outer EUV front crosses the spectrometer sampling geometry in the published analysis. The strong later spectrum belongs to the erupting filament. These are different structures within the same eruption, and their quantities must not be combined into one local MHD state.

This is a successful physical association control. It preserves both the observed outer front and the useful spectroscopy of the filament. It does not identify a FAST or SLOW shock and does not prove that the outer front produced no plasma disturbance.

## 1. Scientific basis and credit

The observations and their original physical analysis are credited to Harra and Sterling (2003), *Imaging and Spectroscopic Investigations of a Solar Coronal Wave: Properties of the Wave Front and Associated Erupting Material*, ApJ 587, 429–438, [DOI 10.1086/368079](https://doi.org/10.1086/368079), and Madjarska, Doyle and Shetye (2015), *A coronal wave and an asymmetric eruptive filament in SUMER, CDS, EIT, and TRACE co-observations*, A&A 575, A39, [DOI 10.1051/0004-6361/201424754](https://doi.org/10.1051/0004-6361/201424754), [author manuscript](https://arxiv.org/abs/1412.1984). Their interpretation of an outer fast-mode wave is retained as a published interpretation, not supplied to an RMO classifier as a family label.

R138 first recovered the accepted project audits 19 and 19A, then inspected the complete Madjarska manuscript and its Figure 2. The new work is an explicit association and inference audit. No raw TRACE, EIT, CDS or SUMER arrays were downloaded or reprocessed. No new spectral fit, registration, front trajectory, temperature inversion or MHD root survey was performed. The 2003 full-text endpoint was inaccessible in this pass; statements attributed to that paper are supported here by the retained audits and the explicit account in the 2015 manuscript. This is recorded as an access limit, not missing observations.

The source PDF identifies itself as arXiv:1412.1984v1, submitted in December 2014, while its typeset header says July 2018. The published study is cited as 2015. This header discrepancy does not change the June 1998 event date. The source receipt records the exact downloaded bytes and locations inspected. Original source papers remain external references; the package preserves the evidence ledger and the three previously accepted project audits.

## 2. Which object is being measured?

| Structure or signal | Supported association | Allowed use |
|---|---|---|
| Weak outer propagating front in TRACE/EIT | The published co-registration places it across the CDS field and beneath the SUMER slit. | Positive source-level crossing; image kinematics and the appropriately conditioned spectral non-detection. |
| Bright compression and dimming behind the outer front | A separate component in the published interpretation; it disperses before reaching SUMER. | Context for feature separation. Figure 2 semicircles and Table 2 dimming speeds must not replace the outer-front local geometry. |
| Later large CDS/SUMER Doppler components | Asymmetric eruptive filament, identified using imaging and spectroscopy together. | Filament dynamics and spectral properties; not the earlier outer-front plasma velocity. |
| Quiet/reference emission | A line reference and background contribution, not demonstrated local upstream plasma. | Wavelength reference with its uncertainty; no automatic upstream-state assignment. |

**Same physical object? NO for the outer front and the later positive filament spectrum.**

**Did the outer front cross the spectrometer sampling geometry? YES at the level established in the published study.**

These answers address different questions. A source-supported crossing does not imply a resolved positive spectrum. Conversely, a weak or absent spectral response does not imply that the instrument missed the front spatially. A CDS field-of-view crossing also does not provide a newly verified exposure time for every raster pixel.

## 3. Timing and sampling

The source Figure 2 gives twelve TRACE 195 Å image labels from 15:28:54 to 15:45:11 UT. Their consecutive separations are **62, 90, 114, 72, 89, 114, 72, 88, 115, 73 and 88 seconds**. This is an irregular image sequence, not one fixed cadence. The earlier accepted 72–114 s range described its smaller retained subset; that inherited record is unchanged.

| SUMER source interval, UT | Wavelength window | Source-supported object/response |
|---|---|---|
| Approximately 15:31–15:39 | Around 770 Å | Outer-front passage during the integration; no detected wave signature. |
| Approximately 15:39–15:47 | Around 770 Å | Blue-shifted transition-region filament emission. |
| Approximately 15:48–15:56 | Around 1238 Å | Filament emission. |
| Approximately 15:56–16:03, as printed | Around 1238 Å | Filament emission; preserve the rounded endpoint. |

The reported observing mode used a 1 arcsec by 300 arcsec slit and 480 s integrations. These published minute labels are not archive-exact exposure timestamps. Section 2 mentions 15:39 UT, while section 3.2 explicitly describes the first exposure as 15:31–15:39 UT. The latter supplies the front-passage account. Figure 8's last rounded interval spans seven minutes despite the nominal 480 s mode; R138 does not repair it by inventing an endpoint. Neither discrepancy affects the separation between the first wave non-detection and the later filament spectra.

The filament entered the CDS field after about 15:34 UT and was scanned in the raster starting at 15:37 UT. Further reported starts are 15:42, 15:47, 15:53 and 15:58 UT. A raster is a map assembled at different times, not an instantaneous state pair. Exact crossing-pixel exposure times and their uncertainty were not reconstructed in R138. The event-specific complete EIT cadence remains unspecified.

A front crossing time cannot be calculated by dividing the slit width by the quoted image speed. The duration of the front contribution also depends on its emitting width, motion relative to the slit, line-of-sight integration and emissivity. Those quantities are not supplied for a quantitative dilution correction here.

## 4. What the spectral non-detection does constrain

The retained CDS account reports no substantial line shift at the weak front and an approximate response scale below **10 km/s**. R138 preserves this as an instrument-conditioned, source-derived LOS result. It is not a measured bound on the intrinsic normal plasma velocity, a front speed, or a new confidence interval.

SUMER did not detect the wave in its first integration. The useful lines in that window have formation-response peaks around log10(Tmax/K) = 4.9–5.8. These are line-response properties, not a measured temperature interval of the outer front. The source discusses temperature response, faint emission and long integration as explanations. R138 does not turn the non-detection into a hard lower temperature bound or an exclusion of a wave or shock.

The physical reason is straightforward: a spectrum mixes emission from several places and times. In a conditional optically thin, nonrelativistic centroid model,

\[
v_{\mathrm{centroid}}=
\frac{\sum_j\int_{\Delta t}\int_{\mathrm{LOS}}\epsilon_j\,v_{j,\mathrm{LOS}}\,ds\,dt}
{\sum_j\int_{\Delta t}\int_{\mathrm{LOS}}\epsilon_j\,ds\,dt}.
\]

Here the instrumental spatial and spectral response is implicit; a quantitative forward model must include it. In the illustrative case of a stationary background plus front emission, this becomes

\[
v_{\mathrm{centroid}}=f_{\mathrm{line}}v_{\mathrm{front,LOS}},
\qquad 0\le f_{\mathrm{line}}\le1.
\]

Without an observationally supported positive lower bound on the line-emission weight, a small centroid alone gives no finite intrinsic-flow upper bound. Moreover,

\[
v_{\mathrm{front,LOS}}=v_n(\hat{\mathbf n}\cdot\hat{\mathbf l})+
\mathbf v_t\cdot\hat{\mathbf l}.
\]

Neither the relevant local geometry nor the tangential contribution is determined here. These equations explain the inference limit; they are **ASSUMED / MODEL_DERIVED illustrations**, not a calibrated E08 correction or a new state reconstruction. The published Gaussian-fit results need not equal a simple centroid in a blended multicomponent spectrum.

## 5. Filament and blend controls

The later body and leading-edge Doppler components, approximately 150 and 300–350 km/s in the retained accounts, are assigned to the filament. They are not the plasma velocity jump of the earlier outer front. A later sharp Doppler increase reflects faster material entering the slit, rather than demonstrating acceleration of one continuously tracked plasma element.

Madjarska and colleagues tested the unresolved Mg X 609.79 Å / O IV 609.83 Å feature using the O IV lines near 554 Å and CHIANTI v7.1.3. Their selected blue-wing ratio, 4.48, is compared with calculated O IV ratios around 3.65–4.27 over the stated temperature range. Their interpretation is that the wing can be supplied by O IV. R138 preserves this published correction; it does not recompute atomic emissivities or claim exact equality of those ratios. The relevant extraction was a 5 by 3 pixel region in the 15:42 UT CDS raster, **of the filament**.

Consequently the 609 Å wing does not establish a hot coronal component or a temperature jump at the outer front. The veto is scoped to this proposed inference. It does not assert that every background coronal photon is absent. Formation temperatures, a line blend and a passband brightening must not substitute for a measured thermodynamic state.

## 6. Provenance and MHD-state gate

| Label | R138 use |
|---|---|
| MEASURED | No new R138 solar measurements. The original observations belong to their observers and instrument teams. |
| SOURCE_DERIVED | Feature identity, passage intervals, published Doppler response, line information, frame labels and differences between those labels. |
| ASSUMED | Explicit optically thin/two-component conditions used only to explain dilution. No assumed E08 height, normal, upstream rest or shock family. |
| MODEL_DERIVED | Conditional centroid relation and its inference limit. No new event-specific MHD state or root. |

For a specified fluid and equation of state, a local ideal-MHD state contains mass density, thermal pressure, the plasma-velocity vector and the magnetic-field vector. Temperature is related to pressure and density through composition and the equation of state; it is not always a further independent variable. Classifying a discontinuity also requires the relation between states on its two sides, its normal and its rest frame.

The state quantities must refer to physically associated local plasma. An image-pattern speed, a later filament velocity and a blended intensity do not form such a state merely because they occur in one eruption.

The R138 family set is therefore **not evaluated**, recorded as `null`. The scoped root execution record is empty because no input problem was posed; it is not evidence of zero physical solutions. Conservation, energy, entropy and characteristic checks are not claimed to have run. There is no numerical failure and no independent R138 exclusion of FAST, SLOW or another family.

## 7. Closure and physical result

**Current status:** feature-association control resolved; outer-front family selection not identified.

**Missing observable:** a separable, calibrated plasma response belonging to the outer-front crossing itself, with exposure and background/emission-weight uncertainty bounded.

**Minimum additional observation:** a spatially registered, time-resolved coronal spectrum of that front passage, with adequate line response, blend control and sensitivity. Family classification would additionally require enough matched local upstream/downstream and geometric information for an MHD test. No numeric cadence, velocity precision or family separator is manufactured without the local emission and state domain.

**Quantitative criterion:** the front-associated spectral response must be distinguishable from background and filament alternatives after the full sampling and uncertainty model is applied. Its supported state domain must then permit physical conservation and admissibility tests. The present below-10-km/s response scale alone does not satisfy either requirement.

**E08 R138 RESULT:** ASSOCIATION CONTROL RESOLVED; OUTER-FRONT MHD FAMILY NOT IDENTIFIED.

**Imaging structure:** weak outer propagating EUV front, distinct in the source analysis from compression/dimming and filament.

**Spectroscopic structure:** the strong later signal is filament emission; the front's earlier passage has an instrument-conditioned non-detection.

**Same physical object?** NO for that outer front and the positive later spectrum; YES for published geometric front sampling.

**Can spectroscopy constrain the outer-front MHD family?** It bounds the recorded spectral response under the observing conditions, but does not select an MHD family.

**What incorrect inference does this control prevent?** Constructing a fictitious shock state from different structures, turning an unresolved blend into a hot-front diagnostic, or interpreting a non-detection as proof that the imaged wave is absent.

## 8. Reproducibility and limits

The update includes three unchanged retained control notes, primary-source identity and access records, twelve page-referenced evidence items, timing and provenance tables, ten explicit inference controls, the scoped root record, the analytic dilution explanation, code, figures, logs and verification. Published-source interpretation and RMO's inference limits remain separately labelled. The code regenerates this evidence control; it does not reanalyse unavailable observational arrays.

R137 and every inherited checkpoint file remain byte-for-byte unchanged. Packaging PASS refers to membership, hashes and reconstruction, not a claim that the outer front has now been classified.