{"paper":{"title":"NICER study of pulsed thermal X-rays from Calvera: a neutron star born in the Galactic halo?","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"L. Baldeschi, M. Rigoselli, R. Taverna, R. Turolla, S. Crestan, S. Mereghetti, S. Zane","submitted_at":"2021-10-28T07:40:26Z","abstract_excerpt":"Calvera (1RXS J141256.0+792204) is an isolated neutron star detected only through its thermal X-ray emission. Its location at high Galactic latitude ($b=+37^\\circ$) is unusual if Calvera is a relatively young pulsar, as suggested by its spin period (59 ms) and period derivative ($3.2 \\times 10^{-15}$ Hz s$^{-1}$). Using the Neutron Star Interior Composition Explorer (NICER), we obtained a phase-connected timing solution spanning four years which allowed us to measure the second derivative of the frequency $\\ddot\\nu = -2.5 \\times 10^{-23}$ Hz s$^{-2}$ and to reveal timing noise consistent with "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2110.14930","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/2110.14930/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"}