Pith Number

pith:L73FTK7Q

pith:2026:L73FTK7QM3UECB4LIPCLQOJ22D

not attested not anchored not stored refs resolved

Compact HII Regions as Clocks of Massive-Star Formation: Evidence for Long Formation Timescales

Mark Gieles, Paolo Padoan

Compact HII regions act as clocks showing massive stars form over Myr timescales that increase with final mass.

arxiv:2602.06196 v2 · 2026-02-05 · astro-ph.SR

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\usepackage{pith}
\pithnumber{L73FTK7QM3UECB4LIPCLQOJ22D}

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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 joint LF constraints imply a growth law in which the formation time is about 4 Myr for a 60 M⊙ star, with an approximately square-root dependence on mass, as predicted by the IIM.

C2weakest assumption

That the compact-HII-region phase lifetime is set solely by the time the star spends above a given ionizing luminosity while still accreting, with no significant contribution from other effects such as dust absorption or dynamical disruption of the region.

C3one line summary

Massive stars in the Milky Way form over Myr timescales that increase with final mass, inferred from joint LF fitting of compact HII regions and OB stars under the inertial-inflow model.

References

45 extracted · 45 resolved · 2 Pith anchors

[1] 2023, A&A, 674, A27, doi: 10.1051/0004-6361/202243813 2023 · doi:10.1051/0004-6361/202243813

[2] 2001, MNRAS, 322, 231, doi: 10.1046/j.1365-8711.2001.04022.x 2001 · doi:10.1046/j.1365-8711.2001.04270.x

[3] 2001, MNRAS, 322, 231, doi: 10.1046/j.1365-8711.2001.04022.x 2001 · doi:10.1046/j.1365-8711.2001.04311.x

[4] J., Saxena, A., Cameron, A 2023 · doi:10.1051/0004-6361/202346159

[5] doi:10.3847/1538-4357/ad5f88 2024 · doi:10.3847/1538-4357/ad5f88

Receipt and verification

First computed	2026-05-18T03:09:23.780326Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

5ff659abf066e841078b43c4b8393ad0d454eb08829a330004f64795533a8bc8

Aliases

arxiv: 2602.06196 · arxiv_version: 2602.06196v2 · doi: 10.48550/arxiv.2602.06196 · pith_short_12: L73FTK7QM3UE · pith_short_16: L73FTK7QM3UECB4L · pith_short_8: L73FTK7Q

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/L73FTK7QM3UECB4LIPCLQOJ22D \
  | 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: 5ff659abf066e841078b43c4b8393ad0d454eb08829a330004f64795533a8bc8

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "154d327db97bcb08ad2b360bc62b23e236ce427a4b9b24b59dc95551471581d9",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "astro-ph.SR",
    "submitted_at": "2026-02-05T21:11:27Z",
    "title_canon_sha256": "36d5e6a636fe9b197b50d479117c0a726d429c0a15d3ca554345f1a24ae7ea7d"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2602.06196",
    "kind": "arxiv",
    "version": 2
  }
}