{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:NFHOKUP3Z7HIXWTHSBDUYLODVL","short_pith_number":"pith:NFHOKUP3","canonical_record":{"source":{"id":"2108.00284","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2021-07-31T16:44:19Z","cross_cats_sorted":[],"title_canon_sha256":"9190ebb7faed9e42343859097647dac775ab01d25be71385fb2ab309e862d13e","abstract_canon_sha256":"b780236b59df81adf8cbb9bca6d45d70604f23668f0e76fd6d636c2ac279777f"},"schema_version":"1.0"},"canonical_sha256":"694ee551fbcfce8bda6790474c2dc3aaca84c5420b6725d953eab76b4ad613e0","source":{"kind":"arxiv","id":"2108.00284","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2108.00284","created_at":"2026-07-05T03:26:03Z"},{"alias_kind":"arxiv_version","alias_value":"2108.00284v1","created_at":"2026-07-05T03:26:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2108.00284","created_at":"2026-07-05T03:26:03Z"},{"alias_kind":"pith_short_12","alias_value":"NFHOKUP3Z7HI","created_at":"2026-07-05T03:26:03Z"},{"alias_kind":"pith_short_16","alias_value":"NFHOKUP3Z7HIXWTH","created_at":"2026-07-05T03:26:03Z"},{"alias_kind":"pith_short_8","alias_value":"NFHOKUP3","created_at":"2026-07-05T03:26:03Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:NFHOKUP3Z7HIXWTHSBDUYLODVL","target":"record","payload":{"canonical_record":{"source":{"id":"2108.00284","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2021-07-31T16:44:19Z","cross_cats_sorted":[],"title_canon_sha256":"9190ebb7faed9e42343859097647dac775ab01d25be71385fb2ab309e862d13e","abstract_canon_sha256":"b780236b59df81adf8cbb9bca6d45d70604f23668f0e76fd6d636c2ac279777f"},"schema_version":"1.0"},"canonical_sha256":"694ee551fbcfce8bda6790474c2dc3aaca84c5420b6725d953eab76b4ad613e0","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T03:26:03.589756Z","signature_b64":"PCv9y1Zui7PgkhNbbpapzlNxPGd6alRJGOzqvXGu65brWxBv4XL8YqYwTIclOFlJlWMVtz2IxlbtwnKmbeM5Cw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"694ee551fbcfce8bda6790474c2dc3aaca84c5420b6725d953eab76b4ad613e0","last_reissued_at":"2026-07-05T03:26:03.589157Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T03:26:03.589157Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2108.00284","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":"2026-07-05T03:26:03Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"R+e+NZcRet/lEJCOtGSvN5v3fe1/6CxmM/uHBPvG2CP93YACj1/HPZVtW6BliM21d4zNl1SnHDRohqyHVOm2Ag==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-05T14:14:48.526102Z"},"content_sha256":"ce35572786421abf979a2872372e19b2f8bd3c0e6ef14c46dcdabed21647fc4a","schema_version":"1.0","event_id":"sha256:ce35572786421abf979a2872372e19b2f8bd3c0e6ef14c46dcdabed21647fc4a"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:NFHOKUP3Z7HIXWTHSBDUYLODVL","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The Instrument of the Imaging X-ray Polarimetry Explorer","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.IM","authors_text":"Ajay Ratheesh, Alberto Manfreda, Alda Rubini, Alessandro Brez, Alessandro Di Marco, Alessandro Profeti, Alessio Nuti, Alessio Trois, Alfredo Morbidini, Andrea Sciortino, Antonino Tobia, Asami Hayato, Barbara Negri, Carlo Lefevre, Carlo Magazzu, Carmelo Sgr\\`o, Ciro Caporale, Claudia Cardelli, Daniele Brienza, Elio Mangraviti, Elisabetta Cavazzuti, Elisa D' Alba, Emanuele Scalise, Enrico Costa, Ettore Del Monte, Fabio Borotto, Fabio D' Amico, Fabio La Monaca, Fabio Muleri, Fabrizio Amici, Federico Mosti, Fei Xie, Francesco Santoli, Giorgio Matt, Giuseppe Di Persio, Gloria Spandre, Hans Andersson, Hikmat Nasimi, Immacolata Donnarumma, John Rankin, Leonardo Lucchesi, Leonardo Orsini, Luca Baldini, Luca Cavalli, Luca Latronico, Marcello Tardiola, Marco Castronuovo, Marco Ceccanti, Marco Marengo, Marco Vimercati, Massimo Minuti, Matteo Bachetti, Matteo Perri, Mattia Barbanera, Maura Pilia, Mauro Centrone, Melissa Pesce Rollins, Michele Pinchera, Niccol\\`o Di Lalla, Paolo Lorenzi, Paolo Mereu, Paolo Sarra, Paolo Soffitta, Pasqualino Loffredo, Primo Attin\\`a, Raffaele Piazzolla, Riccardo Ferrazzoli, Rita Carpentiero, Ronaldo Bellazzini, Saverio Citraro, Seppo Nenonen, Sergio Di Cosimo, Sergio Fabiani, Simone Castellano, Simone Maldera, Simonetta Puccetti, Stefano Ciprini, Takao Kitaguchi, Toru Tamagawa, Toshio Nakano, Yuri Evangelista","submitted_at":"2021-07-31T16:44:19Z","abstract_excerpt":"While X-ray Spectroscopy, Timing and Imaging have improved verymuch since 1962, when the first astronomical non-solar source was discovered, especially with the launch of Newton/X-ray Multi-Mirror Mission, Rossi/X-ray Timing Explorer and Chandra/Advanced X-ray Astrophysics Facility, the progress of X-ray polarimetry has been meager. This is in part due to the lack of sensitive polarization detectors, in part due to the fate of approved missions and in part because the celestial X-ray sources appeared less polarized than expected. Only one positive measurement has been available until now. Inde"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2108.00284","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2108.00284/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2026-07-05T03:26:03Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"OZADOj8+YeRDN+l8I1qc6NVHn2hl+0Gz0EwYbpu2CUwAjTW85kyYMTGUXcONGYbofwatRFwrbH5hk+/PfoavBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-05T14:14:48.526770Z"},"content_sha256":"c64f0e07e99986d85fb7ddd06a45e996a35aefb2f7f5e4909c87dbff0ea9aef2","schema_version":"1.0","event_id":"sha256:c64f0e07e99986d85fb7ddd06a45e996a35aefb2f7f5e4909c87dbff0ea9aef2"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/NFHOKUP3Z7HIXWTHSBDUYLODVL/bundle.json","state_url":"https://pith.science/pith/NFHOKUP3Z7HIXWTHSBDUYLODVL/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/NFHOKUP3Z7HIXWTHSBDUYLODVL/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":"2026-07-05T14:14:48Z","links":{"resolver":"https://pith.science/pith/NFHOKUP3Z7HIXWTHSBDUYLODVL","bundle":"https://pith.science/pith/NFHOKUP3Z7HIXWTHSBDUYLODVL/bundle.json","state":"https://pith.science/pith/NFHOKUP3Z7HIXWTHSBDUYLODVL/state.json","well_known_bundle":"https://pith.science/.well-known/pith/NFHOKUP3Z7HIXWTHSBDUYLODVL/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:NFHOKUP3Z7HIXWTHSBDUYLODVL","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":"b780236b59df81adf8cbb9bca6d45d70604f23668f0e76fd6d636c2ac279777f","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2021-07-31T16:44:19Z","title_canon_sha256":"9190ebb7faed9e42343859097647dac775ab01d25be71385fb2ab309e862d13e"},"schema_version":"1.0","source":{"id":"2108.00284","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2108.00284","created_at":"2026-07-05T03:26:03Z"},{"alias_kind":"arxiv_version","alias_value":"2108.00284v1","created_at":"2026-07-05T03:26:03Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2108.00284","created_at":"2026-07-05T03:26:03Z"},{"alias_kind":"pith_short_12","alias_value":"NFHOKUP3Z7HI","created_at":"2026-07-05T03:26:03Z"},{"alias_kind":"pith_short_16","alias_value":"NFHOKUP3Z7HIXWTH","created_at":"2026-07-05T03:26:03Z"},{"alias_kind":"pith_short_8","alias_value":"NFHOKUP3","created_at":"2026-07-05T03:26:03Z"}],"graph_snapshots":[{"event_id":"sha256:c64f0e07e99986d85fb7ddd06a45e996a35aefb2f7f5e4909c87dbff0ea9aef2","target":"graph","created_at":"2026-07-05T03:26:03Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2108.00284/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"While X-ray Spectroscopy, Timing and Imaging have improved verymuch since 1962, when the first astronomical non-solar source was discovered, especially with the launch of Newton/X-ray Multi-Mirror Mission, Rossi/X-ray Timing Explorer and Chandra/Advanced X-ray Astrophysics Facility, the progress of X-ray polarimetry has been meager. This is in part due to the lack of sensitive polarization detectors, in part due to the fate of approved missions and in part because the celestial X-ray sources appeared less polarized than expected. Only one positive measurement has been available until now. Inde","authors_text":"Ajay Ratheesh, Alberto Manfreda, Alda Rubini, Alessandro Brez, Alessandro Di Marco, Alessandro Profeti, Alessio Nuti, Alessio Trois, Alfredo Morbidini, Andrea Sciortino, Antonino Tobia, Asami Hayato, Barbara Negri, Carlo Lefevre, Carlo Magazzu, Carmelo Sgr\\`o, Ciro Caporale, Claudia Cardelli, Daniele Brienza, Elio Mangraviti, Elisabetta Cavazzuti, Elisa D' Alba, Emanuele Scalise, Enrico Costa, Ettore Del Monte, Fabio Borotto, Fabio D' Amico, Fabio La Monaca, Fabio Muleri, Fabrizio Amici, Federico Mosti, Fei Xie, Francesco Santoli, Giorgio Matt, Giuseppe Di Persio, Gloria Spandre, Hans Andersson, Hikmat Nasimi, Immacolata Donnarumma, John Rankin, Leonardo Lucchesi, Leonardo Orsini, Luca Baldini, Luca Cavalli, Luca Latronico, Marcello Tardiola, Marco Castronuovo, Marco Ceccanti, Marco Marengo, Marco Vimercati, Massimo Minuti, Matteo Bachetti, Matteo Perri, Mattia Barbanera, Maura Pilia, Mauro Centrone, Melissa Pesce Rollins, Michele Pinchera, Niccol\\`o Di Lalla, Paolo Lorenzi, Paolo Mereu, Paolo Sarra, Paolo Soffitta, Pasqualino Loffredo, Primo Attin\\`a, Raffaele Piazzolla, Riccardo Ferrazzoli, Rita Carpentiero, Ronaldo Bellazzini, Saverio Citraro, Seppo Nenonen, Sergio Di Cosimo, Sergio Fabiani, Simone Castellano, Simone Maldera, Simonetta Puccetti, Stefano Ciprini, Takao Kitaguchi, Toru Tamagawa, Toshio Nakano, Yuri Evangelista","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2021-07-31T16:44:19Z","title":"The Instrument of the Imaging X-ray Polarimetry Explorer"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2108.00284","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:ce35572786421abf979a2872372e19b2f8bd3c0e6ef14c46dcdabed21647fc4a","target":"record","created_at":"2026-07-05T03:26:03Z","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":"b780236b59df81adf8cbb9bca6d45d70604f23668f0e76fd6d636c2ac279777f","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"astro-ph.IM","submitted_at":"2021-07-31T16:44:19Z","title_canon_sha256":"9190ebb7faed9e42343859097647dac775ab01d25be71385fb2ab309e862d13e"},"schema_version":"1.0","source":{"id":"2108.00284","kind":"arxiv","version":1}},"canonical_sha256":"694ee551fbcfce8bda6790474c2dc3aaca84c5420b6725d953eab76b4ad613e0","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"694ee551fbcfce8bda6790474c2dc3aaca84c5420b6725d953eab76b4ad613e0","first_computed_at":"2026-07-05T03:26:03.589157Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T03:26:03.589157Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"PCv9y1Zui7PgkhNbbpapzlNxPGd6alRJGOzqvXGu65brWxBv4XL8YqYwTIclOFlJlWMVtz2IxlbtwnKmbeM5Cw==","signature_status":"signed_v1","signed_at":"2026-07-05T03:26:03.589756Z","signed_message":"canonical_sha256_bytes"},"source_id":"2108.00284","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:ce35572786421abf979a2872372e19b2f8bd3c0e6ef14c46dcdabed21647fc4a","sha256:c64f0e07e99986d85fb7ddd06a45e996a35aefb2f7f5e4909c87dbff0ea9aef2"],"state_sha256":"c14eb9b3886dc99b7e6e3a0365b40dd9e34a46455e22da70dba64d9b5b50efbe"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"JVMxz72sHoFcIlmT90K5t4/Qe0M0LEUUvlHYlzoOlpOEwe0jbwnu2a9ngeNgvQp8+t9ZkSmKwWb0VxbjHqUzDg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-05T14:14:48.530017Z","bundle_sha256":"dec6cf721263ab50f7caea31354a481f177c335cd214604e890d3769b541db15"}}