Pith Number

pith:Y7GXWYDZ

pith:2003:Y7GXWYDZ5XIHPRYHAUXSFGRIJF

not attested not anchored not stored refs pending

Chandra and XMM-Newton observations of the first quasars: X-rays from the age of cosmic enlightenment

Astronomy, C. Vignali (1), D.P. Schneider (1), G.T. Richards (4), Israel), J.E. Gunn (4), Michael A. Strauss (4) ((1) Department of Astronomy & Astrophysics, Seattle, S.F. Anderson (2), S. Kaspi (5), Tel-Aviv University, The Pennsylvania State University, The University of Arizona, Tucson, University of Washington, University Park, USA; (2) Astronomy Department, USA; (3) Steward Observatory, USA; (4) Princeton University Observatory, USA; (5) School of Physics, W.N. Brandt (1), X. Fan (3)

arxiv:astro-ph/0302558 v1 · 2003-02-26 · 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{Y7GXWYDZ5XIHPRYHAUXSFGRIJF}

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	2026-07-04T16:36:33.542699Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

c7cd7b6079edd077c707052f229a28497ec9f9250a53fa4965b67f60114026bd

Aliases

arxiv: astro-ph/0302558 · arxiv_version: astro-ph/0302558v1 · doi: 10.48550/arxiv.astro-ph/0302558 · pith_short_12: Y7GXWYDZ5XIH · pith_short_16: Y7GXWYDZ5XIHPRYH · pith_short_8: Y7GXWYDZ

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/Y7GXWYDZ5XIHPRYHAUXSFGRIJF \
  | 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: c7cd7b6079edd077c707052f229a28497ec9f9250a53fa4965b67f60114026bd

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "16b573ac9494ad67bb8f12cdfcf9eaef1ff52f036af7f179948fc600a7d7cfc3",
    "cross_cats_sorted": [],
    "license": "",
    "primary_cat": "astro-ph",
    "submitted_at": "2003-02-26T21:00:03Z",
    "title_canon_sha256": "37e2bac62eff5c337051d288f44eb887ee02278e69c97cfb7b34d0eb921a666c"
  },
  "schema_version": "1.0",
  "source": {
    "id": "astro-ph/0302558",
    "kind": "arxiv",
    "version": 1
  }
}