{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2009:C7NLJ7PTW45OHW7JR6VEV6OVHW","short_pith_number":"pith:C7NLJ7PT","canonical_record":{"source":{"id":"0904.4928","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2009-04-30T19:51:53Z","cross_cats_sorted":[],"title_canon_sha256":"f655700997a7573a7fd0578de6ace5ec89d2480a30ea6714bbacf26b1446935f","abstract_canon_sha256":"84b38b48c2591c0a67c91e47032c471b438e9831f832cd5a3f5ff5107bebbfb7"},"schema_version":"1.0"},"canonical_sha256":"17dab4fdf3b73ae3dbe98faa4af9d53db7b5482196cfd6954e0e2e13acc52455","source":{"kind":"arxiv","id":"0904.4928","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0904.4928","created_at":"2026-05-18T02:13:48Z"},{"alias_kind":"arxiv_version","alias_value":"0904.4928v1","created_at":"2026-05-18T02:13:48Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0904.4928","created_at":"2026-05-18T02:13:48Z"},{"alias_kind":"pith_short_12","alias_value":"C7NLJ7PTW45O","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_16","alias_value":"C7NLJ7PTW45OHW7J","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_8","alias_value":"C7NLJ7PT","created_at":"2026-05-18T12:25:58Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2009:C7NLJ7PTW45OHW7JR6VEV6OVHW","target":"record","payload":{"canonical_record":{"source":{"id":"0904.4928","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2009-04-30T19:51:53Z","cross_cats_sorted":[],"title_canon_sha256":"f655700997a7573a7fd0578de6ace5ec89d2480a30ea6714bbacf26b1446935f","abstract_canon_sha256":"84b38b48c2591c0a67c91e47032c471b438e9831f832cd5a3f5ff5107bebbfb7"},"schema_version":"1.0"},"canonical_sha256":"17dab4fdf3b73ae3dbe98faa4af9d53db7b5482196cfd6954e0e2e13acc52455","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:13:48.647487Z","signature_b64":"a6gpUbhMY2KbiPMp08z7Fo1egvVapA+0oZ0ue+JzX2lNk/OpVu3HXIUdpM9fWrnw2tt5XVgrkxMpS+8y/5VyAQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"17dab4fdf3b73ae3dbe98faa4af9d53db7b5482196cfd6954e0e2e13acc52455","last_reissued_at":"2026-05-18T02:13:48.646856Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:13:48.646856Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"0904.4928","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T02:13:48Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"HQ6yMPJvQ/LkMiLJsp/ytCwO1z/BRihB6kIv6vH0JyJpILIkS1gR/vkd/p5a8BV7OO2qpo6IJGy759aS5XSWAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-20T08:46:03.669245Z"},"content_sha256":"72cd6562685dbad0d0bd4c36873689c57761796e791cc83c3afe2f18fd64fdd0","schema_version":"1.0","event_id":"sha256:72cd6562685dbad0d0bd4c36873689c57761796e791cc83c3afe2f18fd64fdd0"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2009:C7NLJ7PTW45OHW7JR6VEV6OVHW","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Extraplanar Dust in Spiral Galaxies: Tracing Outflows in the Disk-Halo Interface","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"J. Christopher Howk (U. Notre Dame)","submitted_at":"2009-04-30T19:51:53Z","abstract_excerpt":"There is now ample evidence that the interstellar thick disks of spiral galaxies are dusty. Although the majority of extraplanar gas in the first few kiloparsecs above the plane of a spiral galaxy is matter that has been expelled from the thin disk, the feedback-driven expulsion does not destroy dust grains altogether (and there is not yet any good measure suggesting it changes the dust-to-gas mass ratio). Direct optical imaging of a majority of edge-on spiral galaxies shows large numbers of dusty clouds populating the thick disk to heights z~2 kpc. These observations are likely revealing a co"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0904.4928","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T02:13:48Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"839NE2iK7SPRlSbmY4wu1JgCJkpBjKvDO9EaMTfwKdcbTawzbUYsssZX77bKXCnoJsN6wJYL/hfTFaTncBPJDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-20T08:46:03.669615Z"},"content_sha256":"fbfe7f8b810c605cd6f6d6f8d016162ecc79450c5cf92a7de2826f0455a8b38f","schema_version":"1.0","event_id":"sha256:fbfe7f8b810c605cd6f6d6f8d016162ecc79450c5cf92a7de2826f0455a8b38f"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/C7NLJ7PTW45OHW7JR6VEV6OVHW/bundle.json","state_url":"https://pith.science/pith/C7NLJ7PTW45OHW7JR6VEV6OVHW/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/C7NLJ7PTW45OHW7JR6VEV6OVHW/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-06-20T08:46:03Z","links":{"resolver":"https://pith.science/pith/C7NLJ7PTW45OHW7JR6VEV6OVHW","bundle":"https://pith.science/pith/C7NLJ7PTW45OHW7JR6VEV6OVHW/bundle.json","state":"https://pith.science/pith/C7NLJ7PTW45OHW7JR6VEV6OVHW/state.json","well_known_bundle":"https://pith.science/.well-known/pith/C7NLJ7PTW45OHW7JR6VEV6OVHW/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2009:C7NLJ7PTW45OHW7JR6VEV6OVHW","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"84b38b48c2591c0a67c91e47032c471b438e9831f832cd5a3f5ff5107bebbfb7","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2009-04-30T19:51:53Z","title_canon_sha256":"f655700997a7573a7fd0578de6ace5ec89d2480a30ea6714bbacf26b1446935f"},"schema_version":"1.0","source":{"id":"0904.4928","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"0904.4928","created_at":"2026-05-18T02:13:48Z"},{"alias_kind":"arxiv_version","alias_value":"0904.4928v1","created_at":"2026-05-18T02:13:48Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0904.4928","created_at":"2026-05-18T02:13:48Z"},{"alias_kind":"pith_short_12","alias_value":"C7NLJ7PTW45O","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_16","alias_value":"C7NLJ7PTW45OHW7J","created_at":"2026-05-18T12:25:58Z"},{"alias_kind":"pith_short_8","alias_value":"C7NLJ7PT","created_at":"2026-05-18T12:25:58Z"}],"graph_snapshots":[{"event_id":"sha256:fbfe7f8b810c605cd6f6d6f8d016162ecc79450c5cf92a7de2826f0455a8b38f","target":"graph","created_at":"2026-05-18T02:13:48Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"There is now ample evidence that the interstellar thick disks of spiral galaxies are dusty. Although the majority of extraplanar gas in the first few kiloparsecs above the plane of a spiral galaxy is matter that has been expelled from the thin disk, the feedback-driven expulsion does not destroy dust grains altogether (and there is not yet any good measure suggesting it changes the dust-to-gas mass ratio). Direct optical imaging of a majority of edge-on spiral galaxies shows large numbers of dusty clouds populating the thick disk to heights z~2 kpc. These observations are likely revealing a co","authors_text":"J. Christopher Howk (U. Notre Dame)","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2009-04-30T19:51:53Z","title":"Extraplanar Dust in Spiral Galaxies: Tracing Outflows in the Disk-Halo Interface"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0904.4928","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:72cd6562685dbad0d0bd4c36873689c57761796e791cc83c3afe2f18fd64fdd0","target":"record","created_at":"2026-05-18T02:13:48Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"84b38b48c2591c0a67c91e47032c471b438e9831f832cd5a3f5ff5107bebbfb7","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.CO","submitted_at":"2009-04-30T19:51:53Z","title_canon_sha256":"f655700997a7573a7fd0578de6ace5ec89d2480a30ea6714bbacf26b1446935f"},"schema_version":"1.0","source":{"id":"0904.4928","kind":"arxiv","version":1}},"canonical_sha256":"17dab4fdf3b73ae3dbe98faa4af9d53db7b5482196cfd6954e0e2e13acc52455","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"17dab4fdf3b73ae3dbe98faa4af9d53db7b5482196cfd6954e0e2e13acc52455","first_computed_at":"2026-05-18T02:13:48.646856Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:13:48.646856Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"a6gpUbhMY2KbiPMp08z7Fo1egvVapA+0oZ0ue+JzX2lNk/OpVu3HXIUdpM9fWrnw2tt5XVgrkxMpS+8y/5VyAQ==","signature_status":"signed_v1","signed_at":"2026-05-18T02:13:48.647487Z","signed_message":"canonical_sha256_bytes"},"source_id":"0904.4928","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:72cd6562685dbad0d0bd4c36873689c57761796e791cc83c3afe2f18fd64fdd0","sha256:fbfe7f8b810c605cd6f6d6f8d016162ecc79450c5cf92a7de2826f0455a8b38f"],"state_sha256":"fd5467378d1ed56c65effe0cf0492b635eb0fc7991a6c5164288bc843891fabb"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"qGj0kPU8un1ceZ+M16H9KRcfm67shpi0NyYD5Dz1s+nSLmchUzRYdIvqCe73knTEd0lypmhc633csRXJ3sU9Dg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-20T08:46:03.671863Z","bundle_sha256":"5c71326d749d8ca5244439c94a07741380d0d134a3d526469005852abb67f193"}}