dc.contributor.author | Ramsey BD | |
dc.contributor.author | Tombesi F | |
dc.contributor.author | Wu K | |
dc.contributor.author | Ferrazzoli R | |
dc.contributor.author | Bachetti M | |
dc.contributor.author | Trois A | |
dc.contributor.author | Bianchi S | |
dc.contributor.author | Sgro C | |
dc.contributor.author | Marinucci A | |
dc.contributor.author | Karas V | |
dc.contributor.author | Bellazzini R | |
dc.contributor.author | Gunji S | |
dc.contributor.author | Spandre G | |
dc.contributor.author | Rankin J | |
dc.contributor.author | Papitto A | |
dc.contributor.author | Manfreda A | |
dc.contributor.author | Castellano S | |
dc.contributor.author | Kitaguchi T | |
dc.contributor.author | Mizuno T | |
dc.contributor.author | Iwakiri W | |
dc.contributor.author | Ng CY | |
dc.contributor.author | De Rosa A | |
dc.contributor.author | Madejski G | |
dc.contributor.author | Marshall HL | |
dc.contributor.author | Ehlert SR | |
dc.contributor.author | Tavecchio F | |
dc.contributor.author | La Monaca F | |
dc.contributor.author | Weisskopf MC | |
dc.contributor.author | Tsygankov S | |
dc.contributor.author | Pacciani L | |
dc.contributor.author | Taverna R | |
dc.contributor.author | Garcia JA | |
dc.contributor.author | Brez A | |
dc.contributor.author | Krawczynski H | |
dc.contributor.author | Bonino R | |
dc.contributor.author | Marscher AP | |
dc.contributor.author | Thomas NE | |
dc.contributor.author | Zane S | |
dc.contributor.author | Jourdain E | |
dc.contributor.author | Bongiorno SD | |
dc.contributor.author | Dovciak M | |
dc.contributor.author | Enoto T | |
dc.contributor.author | Antonelli LA | |
dc.contributor.author | Ratheesh A | |
dc.contributor.author | Hayashida K | |
dc.contributor.author | Turolla R | |
dc.contributor.author | Tawara Y | |
dc.contributor.author | Omodei N | |
dc.contributor.author | Romani RW | |
dc.contributor.author | Doroshenko V | |
dc.contributor.author | Tamagawa T | |
dc.contributor.author | Di Lalla N | |
dc.contributor.author | Rodi J | |
dc.contributor.author | Pavlov GG | |
dc.contributor.author | Capitanio F | |
dc.contributor.author | Bucciantini N | |
dc.contributor.author | Jorstad SG | |
dc.contributor.author | Middei R | |
dc.contributor.author | Negro M | |
dc.contributor.author | Di Gesu L | |
dc.contributor.author | Latronico L | |
dc.contributor.author | Slane P | |
dc.contributor.author | Heyl J | |
dc.contributor.author | Marin F | |
dc.contributor.author | Cavazzuti E | |
dc.contributor.author | Evangelista Y | |
dc.contributor.author | Ciprini S | |
dc.contributor.author | Massaro F | |
dc.contributor.author | Pesce-Rollins M | |
dc.contributor.author | Donnarumma I | |
dc.contributor.author | Roques JP | |
dc.contributor.author | Tennant AF | |
dc.contributor.author | Baumgartner WH | |
dc.contributor.author | Baldini L | |
dc.contributor.author | Fabiani S | |
dc.contributor.author | Liodakis I | |
dc.contributor.author | Pilia M | |
dc.contributor.author | Possenti A | |
dc.contributor.author | Perri M | |
dc.contributor.author | Matt G | |
dc.contributor.author | Barnouin T | |
dc.contributor.author | Peirson AL | |
dc.contributor.author | Muleri F | |
dc.contributor.author | Puccetti S | |
dc.contributor.author | O'Dell SL | |
dc.contributor.author | Maldera S | |
dc.contributor.author | Xie F | |
dc.contributor.author | Vink J | |
dc.contributor.author | Soffitta P | |
dc.contributor.author | Agudo I | |
dc.contributor.author | Del Monte E | |
dc.contributor.author | Costa E | |
dc.contributor.author | Di Marco A | |
dc.contributor.author | Poutanen J | |
dc.contributor.author | Mitsuishi I | |
dc.contributor.author | Kolodziejczak JJ | |
dc.contributor.author | Oppedisano C | |
dc.contributor.author | Petrucci PO | |
dc.date.accessioned | 2022-10-28T13:28:33Z | |
dc.date.available | 2022-10-28T13:28:33Z | |
dc.identifier.uri | https://www.utupub.fi/handle/10024/165436 | |
dc.description.abstract | We present measurements of the polarization of X-rays in the 2-8 keV band from the nucleus of the radio galaxy Centaurus A (Cen A), using a 100 ks observation from the Imaging X-ray Polarimetry Explorer (IXPE). Nearly simultaneous observations of Cen A were also taken with the Swift, NuSTAR, and INTEGRAL observatories. No statistically significant degree of polarization is detected with IXPE. These observations have a minimum detectable polarization at 99% confidence (MDP99) of 6.5% using a weighted, spectral model-independent calculation in the 2-8 keV band. The polarization angle psi is consequently unconstrained. Spectral fitting across three orders of magnitude in X-ray energy (0.3-400 keV) demonstrates that the SED of Cen A is well described by a simple power law with moderate intrinsic absorption (N (H) similar to 10(23) cm(-2)) and a Fe K alpha emission line, although a second unabsorbed power law is required to account for the observed spectrum at energies below 2 keV. This spectrum suggests that the reprocessing material responsible for this emission line is optically thin and distant from the central black hole. Our upper limits on the X-ray polarization are consistent with the predictions of Compton scattering, although the specific seed photon population responsible for the production of the X-rays cannot be identified. The low polarization degree, variability in the core emission, and the relative lack of variability in the Fe K alpha emission line support a picture where electrons are accelerated in a region of highly disordered magnetic fields surrounding the innermost jet. | |
dc.language.iso | en | |
dc.publisher | IOP Publishing Ltd | |
dc.title | Limits on X-Ray Polarization at the Core of Centaurus A as Observed with the Imaging X-Ray Polarimetry Explorer | |
dc.identifier.url | https://iopscience.iop.org/article/10.3847/1538-4357/ac8056 | |
dc.identifier.urn | URN:NBN:fi-fe2022102463059 | |
dc.relation.volume | 935 | |
dc.contributor.organization | fi=Suomen ESO-keskus, yhteiset|en=Finnish Centre for Astronomy with ESO - FINCA| | |
dc.contributor.organization | fi=Tuorlan observatorio|en=Tuorla Observatory| | |
dc.contributor.organization-code | 2606705 | |
dc.contributor.organization-code | 2609700 | |
dc.converis.publication-id | 176536414 | |
dc.converis.url | https://research.utu.fi/converis/portal/Publication/176536414 | |
dc.identifier.eissn | 1538-4357 | |
dc.identifier.jour-issn | 0004-637X | |
dc.okm.affiliatedauthor | Liodakis, Yannis | |
dc.okm.affiliatedauthor | Tsygankov, Sergey | |
dc.okm.affiliatedauthor | Poutanen, Juri | |
dc.okm.discipline | 115 Avaruustieteet ja tähtitiede | fi_FI |
dc.okm.discipline | 115 Astronomy and space science | en_GB |
dc.okm.internationalcopublication | international co-publication | |
dc.okm.internationality | International publication | |
dc.okm.type | Journal article | |
dc.publisher.country | United Kingdom | en_GB |
dc.publisher.country | Britannia | fi_FI |
dc.publisher.country-code | GB | |
dc.relation.articlenumber | 116 | |
dc.relation.doi | 10.3847/1538-4357/ac8056 | |
dc.relation.ispartofjournal | Astrophysical Journal | |
dc.relation.issue | 2 | |
dc.year.issued | 2022 | |