{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2011:WHO7UKYDKM5N24IOOHNS5GGI36","short_pith_number":"pith:WHO7UKYD","canonical_record":{"source":{"id":"1104.1577","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2011-04-08T13:55:00Z","cross_cats_sorted":["astro-ph.SR"],"title_canon_sha256":"7a1f01eed28ca83758017a7c0f8364747269b6efda317ee25841f99761dbfadd","abstract_canon_sha256":"6b5eb4256360096d679049c027a506c795f1b9187f01497ccb4187539c955092"},"schema_version":"1.0"},"canonical_sha256":"b1ddfa2b03533add710e71db2e98c8df8d7ca7cdcaacb914cc16395bd89e35bc","source":{"kind":"arxiv","id":"1104.1577","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1104.1577","created_at":"2026-05-18T02:02:36Z"},{"alias_kind":"arxiv_version","alias_value":"1104.1577v1","created_at":"2026-05-18T02:02:36Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1104.1577","created_at":"2026-05-18T02:02:36Z"},{"alias_kind":"pith_short_12","alias_value":"WHO7UKYDKM5N","created_at":"2026-05-18T12:26:44Z"},{"alias_kind":"pith_short_16","alias_value":"WHO7UKYDKM5N24IO","created_at":"2026-05-18T12:26:44Z"},{"alias_kind":"pith_short_8","alias_value":"WHO7UKYD","created_at":"2026-05-18T12:26:44Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2011:WHO7UKYDKM5N24IOOHNS5GGI36","target":"record","payload":{"canonical_record":{"source":{"id":"1104.1577","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2011-04-08T13:55:00Z","cross_cats_sorted":["astro-ph.SR"],"title_canon_sha256":"7a1f01eed28ca83758017a7c0f8364747269b6efda317ee25841f99761dbfadd","abstract_canon_sha256":"6b5eb4256360096d679049c027a506c795f1b9187f01497ccb4187539c955092"},"schema_version":"1.0"},"canonical_sha256":"b1ddfa2b03533add710e71db2e98c8df8d7ca7cdcaacb914cc16395bd89e35bc","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T02:02:36.286479Z","signature_b64":"F0uq/EizfsY/YF57ArOp0Glg0bz/i/DpdzmXivRWpzSGESB+AjqBvwp+o9pcYrMsAjUSQ06PUNhN9HxpkwJ8DA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"b1ddfa2b03533add710e71db2e98c8df8d7ca7cdcaacb914cc16395bd89e35bc","last_reissued_at":"2026-05-18T02:02:36.285774Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T02:02:36.285774Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1104.1577","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":"2026-05-18T02:02:36Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"S3YoGHYKmf/sD43n7f0hTbrc5qt8Amm1VsZja7IPqvqtb4XiUFoO9K+JDHC57Wd53vCfakWw6AKDl7NrE8M0DA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-01T00:40:09.785267Z"},"content_sha256":"292b60045453a447bab083cbfd900f1f2f6453fa5c5d974d0d9e28a32ad9cf93","schema_version":"1.0","event_id":"sha256:292b60045453a447bab083cbfd900f1f2f6453fa5c5d974d0d9e28a32ad9cf93"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2011:WHO7UKYDKM5N24IOOHNS5GGI36","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Observing pulsars and fast transients with LOFAR","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.SR"],"primary_cat":"astro-ph.IM","authors_text":"A. Alexov, A. Asgekar, A. G. de Bruyn, A. Gunst, A. Horneffer, A. Karastergiou, A. Noutsos, A. Polatidis, A. Schoenmakers, A. van Duin, A. Zensus, B. Ciardi, B. Scheers, B. W. Stappers, C. G. M. Sterks, C. Law, C. Vogt, D. McKay-Bukowski, E. J. Daw, G. Heald, G. Kuper, G. Miley, H. Falcke, H. Holties, H. Olofsson, H. R. Butcher, H. R\\\"ottgering, H. Spreeuw, I. M. Avruch, J. Anderson, J. Bregman, J. Broderick, J. C. A. Miller-Jones, J. Conway, J. D. Mol, J. Eisl\\\"offel, J. E. Noordam, J. Griessmeier, J. P. Hamaker, J. P. McKean, J. Sluman, J. Swinbank, J. van Enst, J. van Leeuwen, J. W . Romein, J. W. T. Hessels, K. Anderson, L. B\\\"ahren, L. V. E. Koopmans, M. Brentjens, M. Br\\\"uggen, M. de Vos, M. E. Bell, M. Garrett, M. Gerbers, M. Hoeft, M. J. Bentum, M. Kramer, M. Loose, M. Norden, M. Pandey-Pommier, M. P. van Haarlem, M. Steinmetz, M. Tagger, M. W. Wise, N. Vermaas, O. Smirnov, O. Wucknitz, P. Bennema, P. Best, P. C. Broekema, P. Maat, P. Weltevrede, P. Zarka, R. A. M. J. Wijers, R. Beck, R. Fender, R. H. van de Brink, R.-J. Dettmar, R. Morganti, R. Nijboer, R. Vermeulen, S. J. Wijnholds, S. Markoff, S. ter Veen, S. Yatawatta, T. Coenen, T. Grit, T. Hassall, V. I. Kondratiev, V. S. Dhillon, W. N. Brouw, W. Reich, Y. Tang","submitted_at":"2011-04-08T13:55:00Z","abstract_excerpt":"Low frequency radio waves, while challenging to observe, are a rich source of information about pulsars. The LOw Frequency ARray (LOFAR) is a new radio interferometer operating in the lowest 4 octaves of the ionospheric \"radio window\": 10-240MHz, that will greatly facilitate observing pulsars at low radio frequencies. Through the huge collecting area, long baselines, and flexible digital hardware, it is expected that LOFAR will revolutionize radio astronomy at the lowest frequencies visible from Earth. LOFAR is a next-generation radio telescope and a pathfinder to the Square Kilometre Array (S"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1104.1577","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":"2026-05-18T02:02:36Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"uVIF0sOxSIX5TG/5qJSFd29dN2j4Gu12PJRt1fI/+ZqeQQkxJ/roZQp2JvOhPcyl0oezvUhYEB23p+EroXH0Cg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-01T00:40:09.785655Z"},"content_sha256":"17c2a5f414ba564cc04b4b14054fd8c0ba996a4c0d20c174299c7f1e464234db","schema_version":"1.0","event_id":"sha256:17c2a5f414ba564cc04b4b14054fd8c0ba996a4c0d20c174299c7f1e464234db"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/WHO7UKYDKM5N24IOOHNS5GGI36/bundle.json","state_url":"https://pith.science/pith/WHO7UKYDKM5N24IOOHNS5GGI36/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/WHO7UKYDKM5N24IOOHNS5GGI36/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":"2026-06-01T00:40:09Z","links":{"resolver":"https://pith.science/pith/WHO7UKYDKM5N24IOOHNS5GGI36","bundle":"https://pith.science/pith/WHO7UKYDKM5N24IOOHNS5GGI36/bundle.json","state":"https://pith.science/pith/WHO7UKYDKM5N24IOOHNS5GGI36/state.json","well_known_bundle":"https://pith.science/.well-known/pith/WHO7UKYDKM5N24IOOHNS5GGI36/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2011:WHO7UKYDKM5N24IOOHNS5GGI36","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":"6b5eb4256360096d679049c027a506c795f1b9187f01497ccb4187539c955092","cross_cats_sorted":["astro-ph.SR"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2011-04-08T13:55:00Z","title_canon_sha256":"7a1f01eed28ca83758017a7c0f8364747269b6efda317ee25841f99761dbfadd"},"schema_version":"1.0","source":{"id":"1104.1577","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1104.1577","created_at":"2026-05-18T02:02:36Z"},{"alias_kind":"arxiv_version","alias_value":"1104.1577v1","created_at":"2026-05-18T02:02:36Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1104.1577","created_at":"2026-05-18T02:02:36Z"},{"alias_kind":"pith_short_12","alias_value":"WHO7UKYDKM5N","created_at":"2026-05-18T12:26:44Z"},{"alias_kind":"pith_short_16","alias_value":"WHO7UKYDKM5N24IO","created_at":"2026-05-18T12:26:44Z"},{"alias_kind":"pith_short_8","alias_value":"WHO7UKYD","created_at":"2026-05-18T12:26:44Z"}],"graph_snapshots":[{"event_id":"sha256:17c2a5f414ba564cc04b4b14054fd8c0ba996a4c0d20c174299c7f1e464234db","target":"graph","created_at":"2026-05-18T02:02:36Z","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":"Low frequency radio waves, while challenging to observe, are a rich source of information about pulsars. The LOw Frequency ARray (LOFAR) is a new radio interferometer operating in the lowest 4 octaves of the ionospheric \"radio window\": 10-240MHz, that will greatly facilitate observing pulsars at low radio frequencies. Through the huge collecting area, long baselines, and flexible digital hardware, it is expected that LOFAR will revolutionize radio astronomy at the lowest frequencies visible from Earth. LOFAR is a next-generation radio telescope and a pathfinder to the Square Kilometre Array (S","authors_text":"A. Alexov, A. Asgekar, A. G. de Bruyn, A. Gunst, A. Horneffer, A. Karastergiou, A. Noutsos, A. Polatidis, A. Schoenmakers, A. van Duin, A. Zensus, B. Ciardi, B. Scheers, B. W. Stappers, C. G. M. Sterks, C. Law, C. Vogt, D. McKay-Bukowski, E. J. Daw, G. Heald, G. Kuper, G. Miley, H. Falcke, H. Holties, H. Olofsson, H. R. Butcher, H. R\\\"ottgering, H. Spreeuw, I. M. Avruch, J. Anderson, J. Bregman, J. Broderick, J. C. A. Miller-Jones, J. Conway, J. D. Mol, J. Eisl\\\"offel, J. E. Noordam, J. Griessmeier, J. P. Hamaker, J. P. McKean, J. Sluman, J. Swinbank, J. van Enst, J. van Leeuwen, J. W . Romein, J. W. T. Hessels, K. Anderson, L. B\\\"ahren, L. V. E. Koopmans, M. Brentjens, M. Br\\\"uggen, M. de Vos, M. E. Bell, M. Garrett, M. Gerbers, M. Hoeft, M. J. Bentum, M. Kramer, M. Loose, M. Norden, M. Pandey-Pommier, M. P. van Haarlem, M. Steinmetz, M. Tagger, M. W. Wise, N. Vermaas, O. Smirnov, O. Wucknitz, P. Bennema, P. Best, P. C. Broekema, P. Maat, P. Weltevrede, P. Zarka, R. A. M. J. Wijers, R. Beck, R. Fender, R. H. van de Brink, R.-J. Dettmar, R. Morganti, R. Nijboer, R. Vermeulen, S. J. Wijnholds, S. Markoff, S. ter Veen, S. Yatawatta, T. Coenen, T. Grit, T. Hassall, V. I. Kondratiev, V. S. Dhillon, W. N. Brouw, W. Reich, Y. Tang","cross_cats":["astro-ph.SR"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2011-04-08T13:55:00Z","title":"Observing pulsars and fast transients with LOFAR"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1104.1577","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":"sha256:292b60045453a447bab083cbfd900f1f2f6453fa5c5d974d0d9e28a32ad9cf93","target":"record","created_at":"2026-05-18T02:02:36Z","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":"6b5eb4256360096d679049c027a506c795f1b9187f01497ccb4187539c955092","cross_cats_sorted":["astro-ph.SR"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2011-04-08T13:55:00Z","title_canon_sha256":"7a1f01eed28ca83758017a7c0f8364747269b6efda317ee25841f99761dbfadd"},"schema_version":"1.0","source":{"id":"1104.1577","kind":"arxiv","version":1}},"canonical_sha256":"b1ddfa2b03533add710e71db2e98c8df8d7ca7cdcaacb914cc16395bd89e35bc","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"b1ddfa2b03533add710e71db2e98c8df8d7ca7cdcaacb914cc16395bd89e35bc","first_computed_at":"2026-05-18T02:02:36.285774Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T02:02:36.285774Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"F0uq/EizfsY/YF57ArOp0Glg0bz/i/DpdzmXivRWpzSGESB+AjqBvwp+o9pcYrMsAjUSQ06PUNhN9HxpkwJ8DA==","signature_status":"signed_v1","signed_at":"2026-05-18T02:02:36.286479Z","signed_message":"canonical_sha256_bytes"},"source_id":"1104.1577","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:292b60045453a447bab083cbfd900f1f2f6453fa5c5d974d0d9e28a32ad9cf93","sha256:17c2a5f414ba564cc04b4b14054fd8c0ba996a4c0d20c174299c7f1e464234db"],"state_sha256":"e11fc3f997b0b902d3ea6bca6857f8103a4635988547e33bb4cb51b954499cd4"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"JdqyLfCUs98U3ineDCjP+RGIBHOKQCzORHTi9KpXn87ZBLGEiyyX7MiiolPe0KCgGY11L9AanjiksIlzszN5Bw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-01T00:40:09.788106Z","bundle_sha256":"4158eebea68f4dd23b1bd23e503cd75974094d977c7044f50b66d67350cc41f0"}}