Pith Number

pith:PDK2BHJA

pith:2001:PDK2BHJAWRKQQNYJLRALCQUXJX

not attested not anchored not stored refs pending

A Chandra HETG Observation of the Quasar H 1821+643 and Its Surrounding Cluster

C. R. Canizares (MIT), D. S. Davis, G. L. Bryan, H. L. Marshall, J. C. Lee, T. Fang

arxiv:astro-ph/0109389 v1 · 2001-09-21 · astro-ph

Open paper page JSON Open Graph Bundle Merged state Verified badge What is a Pith Number?

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{PDK2BHJAWRKQQNYJLRALCQUXJX}

Prints a linked badge after your title and injects PDF metadata. Compiles on arXiv. Learn more · Embed verified badge

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.

Receipt and verification

First computed	2026-05-18T01:40:44.057709Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

78d5a09d20b4550837095c40b142974de4df669d21adc6b638ac8682d12c75ad

Aliases

arxiv: astro-ph/0109389 · arxiv_version: astro-ph/0109389v1 · doi: 10.48550/arxiv.astro-ph/0109389 · pith_short_12: PDK2BHJAWRKQ · pith_short_16: PDK2BHJAWRKQQNYJ · pith_short_8: PDK2BHJA

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/PDK2BHJAWRKQQNYJLRALCQUXJX \
  | 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: 78d5a09d20b4550837095c40b142974de4df669d21adc6b638ac8682d12c75ad

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "8bd563d52ae16efeb51551a3b8ca0bc585186476d91925b15283c39502abf98a",
    "cross_cats_sorted": [],
    "license": "",
    "primary_cat": "astro-ph",
    "submitted_at": "2001-09-21T18:43:26Z",
    "title_canon_sha256": "0eb03371834d2932764c3dc3d0048843cde9a3605c2efdaa0ac1ec46315225fe"
  },
  "schema_version": "1.0",
  "source": {
    "id": "astro-ph/0109389",
    "kind": "arxiv",
    "version": 1
  }
}