X-ray polarization measurement of the gold standard of radio-quiet active galactic nuclei : NGC 1068
Creators: name: Marin, F.
name: Marinucci, A.
name: Laurenti, M.
name: Kim, D. E.
name: Barnouin, T.
name: Di Marco, A.
name: Ursini, F.
name: Bianchi, S.
name: Ravi, S.
name: Marshall, H. L.
name: Matt, G.
name: Chen, C. -T.
name: Gianolli, V. E.
name: Ingram, A.
name: Maksym, W. P.
name: Panagiotou, C.
name: Podgorny, J.
name: Puccetti, S.
name: Ratheesh, A.
name: Tombesi, F.
name: Agudo, I.
name: Antonelli, L. A.
name: Bachetti, M.
name: Baldini, L.
name: Baumgartner, W.
name: Bellazzini, R.
name: Bongiorno, S.
name: Bonino, R.
name: Brez, A.
name: Bucciantini, N.
name: Capitanio, F.
name: Castellano, S.
name: Cavazzuti, E.
name: Ciprini, S.
name: Costa, E.
name: De Rosa, A.
name: Del Monte, E.
name: Di Gesu, L.
name: Di Lalla, N.
name: Donnarumma, I.
name: Doroshenko, V.
name: Dovciak, M.
name: Ehlert, S.
name: Enoto, T.
name: Evangelista, Y.
name: Fabiani, S.
name: Ferrazzoli, R.
name: Garcia, J.
name: Gunji, S.
name: Heyl, J.
name: Iwakiri, W.
name: Jorstad, S.
name: Kaaret, P.
name: Karas, V.
name: Kislat, F.
name: Kitaguchi, T.
name: Kolodziejczak, J.
name: Krawczynski, H.
name: La Monaca, F.
name: Latronico, L.
name: Liodakis, I.
name: Madejski, G.
name: Maldera, S.
name: Manfreda, A.
name: Marscher, A.
name: Massaro, F.
name: Mitsuishi, I.
name: Mizuno, T.
name: Muleri, F.
name: Negro, M.
name: Ng, S.
name: O'Dell, S.
name: Omodei, N.
name: Oppedisano, C.
name: Papitto, A.
name: Pavlov, G.
name: Perri, M.
name: Pesce-Rollins, M.
name: Petrucci, P. -O.
name: Pilia, M.
name: Possenti, A.
name: Poutanen, J.
name: Ramsey, B.
name: Rankin, J.
name: Roberts, O.
name: Romani, R.
name: Sgro, C.
name: Slane, P.
name: Soffitta, P.
name: Spandre, G.
name: Swartz, D.
name: Tamagawa, T.
name: Tavecchio, F.
name: Taverna, R.
name: Tawara, Y.
name: Tennant, A.
name: Thomas, N.
name: Trois, A.
name: Tsygankov, S.
name: Turolla, R.
name: Vink, J.
name: Weisskopf, M.
name: Wu, K.
name: Xie, F.
name: Zane, S.
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences
subject: FOS: Physical sciences
subject: J.2.3; J.2.9
subject: 85-06

description: We used the Imaging X-ray Polarimetry Explorer (IXPE) satellite to measure, for the first time, the 2-8 keV polarization of NGC 1068. We pointed IXPE for a net exposure time of 1.15 Ms on the target, in addition to two ~ 10 ks each Chandra snapshots in order to account for the potential impact of several ultraluminous X-ray source (ULXs) within IXPE's field-of-view. We measured a 2 - 8 keV polarization degree of 12.4% +/- 3.6% and an electric vector polarization angle of 101° +/- 8° at 68% confidence level. If we exclude the spectral region containing the bright Fe K lines and other soft X-ray lines where depolarization occurs, the polarization fraction rises up to 21.3% +/- 6.7% in the 3.5 - 6.0 keV band, with a similar polarization angle. The observed polarization angle is found to be perpendicular to the parsec scale radio jet. Using a combined Chandra and IXPE analysis plus multi-wavelength constraints, we estimated that the circumnuclear "torus" may sustain a half-opening angle of 50° - 55° (from the vertical axis of the system). Thanks to IXPE, we have measured the X-ray polarization of NGC 1068 and found comparable results, both in terms of polarization angle orientation with respect to the radio-jet and torus half-opening angle, to the X-ray polarimetric measurement achieved for the other archetypal Compton-thick AGN : the Circinus galaxy. Probing the geometric arrangement of parsec-scale matter in extragalactic object is now feasible thanks to X-ray polarimetry.
description: 9 pages, 5 figures, 2 tables, submited to A&amp;A