A Direct Empirical Proof of the Existence of Dark Matter
The Astrophysical Journal, 2006 · paper · Astronomy
Presents weak-lensing maps of the colliding galaxy cluster 1E0657-558, where the mass peaks are offset from the hot gas that holds most ordinary matter. The authors claim this 8-sigma offset shows most matter is unseen, not explained by altered gravity.
Checked: PDF from arxiv.org, fetched 4 Oct 2026. Page numbers are those of that PDF.
2 findings
Reference or label Fig. 1 caption says "Shown above in the top panel is a color image from the Magellan images ... In the bottom panel is a 500 ks Chandra image of the cluster", but the two panels are printed side by side (Magellan left, Chandra right).
- p. 2 Fig. 1 caption
Shown above in the top panel is a color image from the Magellan images
- p. 2 Fig. 1 caption
In the bottom panel is a 500 ks Chandra image of the cluster
- p. 2 Fig. 1 caption
In the bottom panel is a 500 ks Chandra image of the cluster.
Judge's note: Viewed the full page 2 image and the caption crop. The optical colour image is the left panel and the X-ray image is the right panel at the same height; there is no top or bottom panel. The caption should read left and right. Meaning is recoverable from content, so this is a label error only.
Second check: another model agreed · checked by hand
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Wording Introduction says "here we add three additional optical image sets" to the archival VLT image, but Section 2 says the dataset "consists of the four sets of optical images shown in Table 1 and the VLT image set used in Clowe et al. (2004)" and refers to "all five data sets".
- p. 2 Section 1, last paragraph but one
here we add three addi-tional optical image sets
- p. 2 Section 2, right column
It consists of the four sets of optical images shown in Table 1 and the VLT image set used in Clowe et al. (2004)
- p. 3 Section 2, continued under Table 1
common to all five data sets
- p. 2 Introduction, last sentence of the paragraph ending before 'In this paper, we measure distances'
here we add three addi-
Only the authors can say what is right here.
Judge's note: Checked page 2 (Introduction and Section 2) and page 3 (Table 1 and text below). Table 1 lists four sets: ESO/MPG WFI, Magellan IMACS, HST ACS subcluster, HST ACS main cluster. Four plus the VLT set gives the 'five data sets' of page 3, so four sets were added, not three. The count of three would hold only if the two ACS pointings were counted as one set (by instrument), but the paper does not say so and Section 2 counts them separately. No explanation found elsewhere in the text. The authors need to say which count is intended.
Second check: another model agreed
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4 minor (typos and the like; most checked by the judge only)
Wording The colour-cut region is called "the rhombus defined by 0.5 < m606 − m814 < 1.5, m435 − m606 > 1.5 ∗ (m606 − m814) − 0.25, and m435 − m606 < 1.6 ∗ (m606 − m814) + 0.4", but the two slanted boundaries have different slopes (1.5 and 1.6), so the region is not a rhombus or parallelogram.
- p. 2 Section 2, last lines of the page
in the rhombus defined by 0.5 < m606 −m814 < 1.5
- p. 3 Section 2, continued under Table 1
m435 −m606 > 1.5 ∗(m606 −m814) −0.25, and m435 −m606 < 1.6∗(m606−m814)+0.4
Judge's note: Checked the end of page 2 and the top of the text on page 3. The slopes are printed as 1.5 and 1.6. The vertical width of the region is 0.70 at colour 0.5 and 0.80 at colour 1.5, so the sides are not parallel. Either 'rhombus' is used loosely for a slanted four-sided box or one slope is a typo; the paper does not let me tell which. Minor wording imprecision unless a slope is wrong.
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Typo Missing article: "The one exception is the single passband HST pointing of main cluster" should read "of the main cluster".
- p. 2 Section 2
single passband HST pointing of main cluster
Judge's note: Read on the page 2 image, right column, Section 2. The text is as quoted; elsewhere the paper writes 'the main cluster'.
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Typo Cosmology given as "Ωm = 0.3, λ = 0.7, H0 = 70km/s/Mpc": the dark-energy density is written as a bare lowercase λ next to Ωm rather than ΩΛ.
- p. 2 Section 1, cosmology sentence
Ωm = 0.3, λ =0.7
Judge's note: Confirmed on the page 2 image and the crop that also shows this line: the glyph is a lowercase λ, so it is not an extraction artefact. Lowercase λ for the normalised cosmological constant is an established older notation, so either form could be legitimate; it is only inconsistent with the Ωm beside it. Notation point, not an error.
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Typo Section 4, first paragraph: "structures capable of providing a signifi-cance amount of κ must lie at z ≲ 0.8". The noun "significance" is used where the adjective is needed; it should read "a significant amount of κ".
- p. 4 Section 4, first paragraph
structures capable of providing a signifi-cance amount of κ must lie at z
- p. 4
structures capable of providing a significance amount of κ
- p. 4 Section 4 Discussion, first paragraph
structures capable of providing a signifi-
- p. 4
structures capable of providing a signifi- cance amount of κ must lie
Judge's note: I checked crop C008-a against page 4. The text is hyphenated "signifi-" / "cance amount of κ" across the line break, so the printed word is "significance" and not an extraction artefact. This is a cosmetic wording slip with an obvious fix.
Second check: another model agreed