Pulsar-wind-nebula-powered Galactic center X-ray filament G0.13- 0.11: Proof of the synchrotron nature by IXPE

Churazov, E.; Khabibullin, I.; Barnouin, T.; Bucciantini, N.; Costa, E.; Di Gesu, L.; Di Marco, A.; Ferrazzoli, R.; Forman, W.; Kaaret, P.; Kim, D. E.; Kolodziejczak, J. J.; Kraft, R.; Marin, F.; Matt, G.; Negro, M.; Romani, R. W.; Silvestri, S.; Soffitta, P.; Sunyaev, R.; Svoboda, J.; Vikhlinin, A.; Weisskopf, M. C.; Xie, F.; Agudo, I.; Antonelli, L. A.; Bachetti, M.; Baldini, L.; Baumgartner, W. H.; Bellazzini, R.; Bianchi, S.; Bongiorno, S. D.; Bonino, R.; Brez, A.; Capitanio, F.; Castellano, S.; Cavazzuti, E.; Chen, C. -T.; Ciprini, S.; De Rosa, A.; Del Monte, E.; Di Lalla, N.; Donnarumma, I.; Doroshenko, V.; Dovciak, M.; Ehlert, S. R.; Enoto, T.; Evangelista, Y.; Fabiani, S.; Garcia, J. A.; Gunji, S.; Hayashida, K.; Heyl, J.; Iwakiri, W.; Jorstad, S. G.; Karas, V.; Kislat, F.; Kitaguchi, T.; Krawczynski, H.; La Monaca, F.; Latronico, L.; Liodakis, I.; Maldera, S.; Manfreda, A.; Marinucci, A.; Marscher, A. P.; Marshall, H. L.; Massaro, F.; Mitsuishi, I.; Mizuno, T.; Muleri, F.; C. -Y., Ng; 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.; Possenti, A.; Poutanen, J.; Puccetti, S.; Ramsey, B. D.; Rankin, J.; Ratheesh, A.; Roberts, O. J.; Sgro, C.; Slane, P.; Spandre, G.; Swartz, D. A.; Tamagawa, T.; Tavecchio, F.; Taverna, R.; Tawara, Y.; Tennant, A. F.; Thomas, N. E.; Tombesi, F.; Trois, A.; Tsygankov, S. S.; Turolla, R.; Vink, J.; Wu, K.; Zane, S.

doi:10.1051/0004-6361/202349080

We report the discovery of X-ray polarization from the X-ray-bright filament G0.13-0.11 in the Galactic center (GC) region. This filament features a bright, hard X-ray source that is most plausibly a pulsar wind nebula (PWN) and an extended and structured diffuse component. Combining the polarization signal from IXPE with the imaging/spectroscopic data from Chandra, we find that X-ray emission of G0.13-0.11 is highly polarized PD = 57(+/-18)% in the 3-6 keV band, while the polarization angle is PA = 21 degrees (+/-9 degrees). This high degree of polarization proves the synchrotron origin of the X-ray emission from G0.13-0.11. In turn, the measured polarization angle implies that the X-ray emission is polarized approximately perpendicular to a sequence of nonthermal radio filaments that may be part of the GC Radio Arc. The magnetic field on the order of 100 mu G appears to be preferentially ordered along the filaments. The above field strength is the fiducial value that makes our model self-consistent, while the other conclusions are largely model independent.