Data di Pubblicazione:
2023
Abstract:
Recent observations with the Imaging X-ray Polarimetry Explorer (IXPE) of two anomalous X-ray pulsars provided evidence that X-ray emission from magnetar sources is strongly polarized. Here we report on the joint IXPE and XMM-Newton observations of the soft γ-repeater SGR 1806-20. The spectral and timing properties of SGR 1806-20 derived from XMM-Newton data are in broad agreement with previous measurements; however, we found the source at an all-time low persistent flux level. No significant polarization was measured apart from the 4-5 keV energy range, where a probable detection with PD = 31.6% ± 10.5% and PA = − 17 .° 6 − 15 .° 0 + 15 .° 5 was obtained. The resulting polarization signal, together with the upper limits we derive at lower and higher energies (2-4 and 5-8 keV, respectively), is compatible with a picture in which thermal radiation from the condensed star surface is reprocessed by resonant Compton scattering in the magnetosphere, similar to what was proposed for the bright magnetar 4U 0142+61.
Tipologia CRIS:
03A-Articolo su Rivista
Elenco autori:
Turolla R.; Taverna R.; Israel G.L.; Muleri F.; Zane S.; Bachetti M.; Heyl J.; Di Marco A.; Gau E.; Krawczynski H.; Ng M.; Possenti A.; Poutanen J.; Baldini L.; Matt G.; Negro M.; Agudo I.; Antonelli L.A.; Baumgartner W.H.; Bellazzini R.; Bianchi S.; Bongiorno S.D.; Bonino R.; Brez A.; Bucciantini N.; Capitanio F.; Castellano S.; Cavazzuti E.; Chen C.-T.; Ciprini S.; Costa E.; De Rosa A.; Del Monte E.; Di Gesu L.; Di Lalla N.; Donnarumma I.; Doroshenko V.; Dovciak M.; Ehlert S.R.; Enoto T.; Evangelista Y.; Fabiani S.; Ferrazzoli R.; Garcia J.A.; Gunji S.; Hayashida K.; Iwakiri W.; Jorstad S.G.; Kaaret P.; Karas V.; Kislat F.; Kitaguchi T.; Kolodziejczak J.J.; La Monaca F.; Latronico L.; Liodakis I.; Maldera S.; Manfreda A.; Marin F.; Marinucci A.; Marscher A.P.; Marshall H.L.; Massaro F.; Mitsuishi I.; Mizuno T.; Ng C.-Y.; O'Dell S.L.; Omodei N.; Oppedisano C.; Papitto A.; Pavlov G.G.; Peirson A.L.; Perri M.; Pesce-Rollins M.; Petrucci P.-O.; Pilia M.; Puccetti S.; Ramsey B.D.; Rankin J.; Ratheesh A.; Roberts O.J.; Romani R.W.; Sgro C.; Slane P.; Soffitta P.; Spandre G.; Swartz D.A.; Tamagawa T.; Tavecchio F.; Tawara Y.; Tennant A.F.; Thomas N.E.; Tombesi F.; Trois A.; Tsygankov S.S.; Vink J.; Weisskopf M.C.; Wu K.; Xie F.
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