Pith Number

pith:J3CXGOTM

pith:2026:J3CXGOTMGHFJ3QPFSXELG32ZFL

not attested not anchored not stored refs resolved

Joining forces: 30 years optical monitoring of the Einstein Cross

A. Esteban-Guti\'errez, A. Sergeyev, A. Yonehara, C. W. Morgan, E. Mediavilla, L. J. Goicoechea, R. Gil-Merino, V. N. Shalyapin

Long-term monitoring of the Einstein Cross quasar shows its optical source size scales nearly linearly with wavelength.

arxiv:2604.09160 v1 · 2026-04-10 · astro-ph.GA

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\usepackage{pith}
\pithnumber{J3CXGOTMGHFJ3QPFSXELG32ZFL}

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Record completeness

1 Bitcoin timestamp

2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

✓ Portable graph bundle live · download bundle · merged state

The bundle contains the canonical record plus signed events. A mirror can host it anywhere and recompute the same current state with the deterministic merge algorithm.

Claims

C1strongest claim

assuming a mean microlens mass ⟨M⟩ = 0.3 M⊙ and concentric Gaussian sources that move according to the velocity distribution peaks (speed and direction) reported in a previous microlensing analysis, we find that the half-light radius of the g-band source is 9.6 ± 2.7 lt-day and the size of the sources grows with wavelength with a power-law index of α = 0.94 ± 0.05.

C2weakest assumption

The sources are concentric Gaussian profiles whose motion follows velocity peaks taken from a prior microlensing study, combined with a fixed mean microlens mass of 0.3 solar masses; any inaccuracy in these inputs directly scales the derived radii and power-law index.

C3one line summary

30-year VRI light curves of the Einstein Cross show the quasar optical source half-light radius scales with wavelength as a power law with index 0.94, giving a g-band size of 9.6 light-days for 0.3 solar-mass microlenses.

References

53 extracted · 53 resolved · 0 Pith anchors

[1] Agol, E., & Krolik, J.\ 1999, ApJ, 524, 49 1999

[2] H.\ 2000, ApJ, 528, 161 2000

[3] Alcalde, D., Mediavilla, E., Moreau, O., et al.\ 2002, ApJ, 572, 729 2002

[4] Anguita, T., Schmidt, R. W., Turner, E. L., et al.\ 2008, A&A, 480, 327 2008

[5] A., & Tsvetkova, V 2017

Receipt and verification

First computed	2026-06-03T14:05:47.326630Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

4ec5733a6c31ca9dc1e595c8b36f592ad92d671da94b98ff8afcc48f8f840718

Aliases

arxiv: 2604.09160 · arxiv_version: 2604.09160v1 · doi: 10.48550/arxiv.2604.09160 · pith_short_12: J3CXGOTMGHFJ · pith_short_16: J3CXGOTMGHFJ3QPF · pith_short_8: J3CXGOTM

Agent API

Resolver JSON Graph JSON Events JSON Schema Signing key

Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/J3CXGOTMGHFJ3QPFSXELG32ZFL \
  | jq -c '.canonical_record' \
  | python3 -c "import sys,json,hashlib; b=json.dumps(json.loads(sys.stdin.read()), sort_keys=True, separators=(',',':'), ensure_ascii=False).encode(); print(hashlib.sha256(b).hexdigest())"
# expect: 4ec5733a6c31ca9dc1e595c8b36f592ad92d671da94b98ff8afcc48f8f840718

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "f977938de49fe8ae2c9ee776d40648a24640bb79ec31f5c101bed32deabd7192",
    "cross_cats_sorted": [],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "astro-ph.GA",
    "submitted_at": "2026-04-10T09:46:15Z",
    "title_canon_sha256": "15794326c05f8c0c0ad665b2648b5fa01e9578662390ba35eb1de80a67dd9df2"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2604.09160",
    "kind": "arxiv",
    "version": 1
  }
}