{"paper":{"title":"First NuSTAR observations of the BL Lac - type blazar PKS~2155-304: constraints on the jet content and distribution of radiating particles","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"A. Hornstrup, A. K. Furniss, A. Zoglauer, B. Giebels, B. Grefenstette, C. Hailey, C. M. Urry, D. Barret, D. M. Alexander, D. Paneque, D. Sanchez, D. Stern, F. A. Harrison, F. E. Christensen, G. M. Madejski, H. Miyasaka, J. Chiang, J. E. Koglin, K. Forster, K. K. Madsen, K. Mori, K. Nalewajko, M. Ajello, M. Balokovi\\'c, M. Hayashida, M. J. Pivovaroff, M. Perri, M. Sikora, N. J. Westergaard, P. Giommi, P. H. Mao, R. D. Blandford, S. E. Boggs, S. Puccetti, T. Kitaguchi, V. Rana, W. W. Craig, W. W. Zhang","submitted_at":"2016-09-07T21:52:07Z","abstract_excerpt":"We report the first hard X-ray observations with NuSTAR of the BL Lac type blazar PKS 2155-304, augmented with soft X-ray data from XMM-Newton and gamma-ray data from the Fermi Large Area Telescope, obtained in April 2013 when the source was in a very low flux state. A joint NuSTAR and XMM spectrum, covering the energy range 0.5 - 60 keV, is best described by a model consisting of a log-parabola component with curvature beta = 0.3(+0.2,-0.1) and a (local) photon index 3.04 +/- 0.15 at photon energy of 2 keV, and a hard power-law tail with photon index 2.2 +/- 0.4. The hard X-ray tail can be sm"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1609.02203","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"}