Pith Number

pith:OEKELPVP

pith:2026:OEKELPVPVVB7IAUQ7IRURLXY4G

not attested not anchored not stored refs resolved

XRISM detection of the 6.4 keV Fe K$\alpha$ line in the radio galaxy Cygnus A

Anwesh Majumder, A. Ptak, A. Simionescu, B.R. McNamara, E. Hodges-Kluck, L. Gu, M.W. Wise, M. Yukita, N. Roy, T. Heckman

XRISM Resolve spectrum reveals two Keplerian Fe Kα components in Cygnus A at distances of 0.1-0.17 pc and 6-10 pc from the black hole.

arxiv:2605.16766 v1 · 2026-05-16 · astro-ph.HE · astro-ph.CO

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\usepackage{pith}
\pithnumber{OEKELPVPVVB7IAUQ7IRURLXY4G}

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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

The broad Fe Kα component arises from a distance of ∼0.1-0.17 pc (800-1400 gravitational radii) and the narrow component from ∼6-10 pc (50,000-80,000 gravitational radii) from the central black hole, for inclinations 50°-85° constrained by VLBI.

C2weakest assumption

The assumption that both line components are purely Keplerian orbits viewed at the VLBI-constrained inclination range of 50°-85°, with no significant contribution from non-gravitational motions or complex geometry that would change the inferred radii (stated in the distance calculation paragraph after the velocity dispersion results).

C3one line summary

XRISM Resolve spectrum of Cygnus A resolves the Fe Kα line into two Keplerian components at ~0.1 pc (broad) and ~6-10 pc (narrow), consistent with BLR and torus origins.

References

57 extracted · 57 resolved · 0 Pith anchors

[1] 1994, Nature, 371, 313, doi: 10.1038/371313a0 Astropy Collaboration, Robitaille, T 1994 · doi:10.1038/371313a0

[2] 1987, ApJ, 320, 537, doi: 10.1086/165571 1987 · doi:10.1086/165571

[3] Zensus, J. A. 2016, Astronomy & Astrophysics, 588, L9, doi: 10.1051/0004-6361/201628412 2016 · doi:10.1051/0004-6361/201628412

[4] 2025, arXiv, doi: 10.48550/arXiv.2507.02195 2025 · doi:10.48550/arxiv.2507.02195

[5] Burtscher, L., Meisenheimer, K., Tristram, K. R. W., et al. 2013, Astronomy & Astrophysics, 558, A149, doi: 10.1051/0004-6361/201321890 2013 · doi:10.1051/0004-6361/201321890

Formal links

2 machine-checked theorem links

Receipt and verification

First computed	2026-05-20T00:03:20.826423Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

711445beafad43f40290fa2348aef8e18348bbe8fab1cdd6b882274ce745f723

Aliases

arxiv: 2605.16766 · arxiv_version: 2605.16766v1 · doi: 10.48550/arxiv.2605.16766 · pith_short_12: OEKELPVPVVB7 · pith_short_16: OEKELPVPVVB7IAUQ · pith_short_8: OEKELPVP

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/OEKELPVPVVB7IAUQ7IRURLXY4G \
  | 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: 711445beafad43f40290fa2348aef8e18348bbe8fab1cdd6b882274ce745f723

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "133507d19ba3f100c2fbc74f98dcfcd04b0cf4d0fefc52a983815755f155ac23",
    "cross_cats_sorted": [
      "astro-ph.CO"
    ],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "astro-ph.HE",
    "submitted_at": "2026-05-16T02:36:55Z",
    "title_canon_sha256": "9a28779976dc5576f0ff09a10cef6c0f5e0d1241848296dea9dc56bfad9099d9"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2605.16766",
    "kind": "arxiv",
    "version": 1
  }
}