TY  - JOUR
A1  - La Monaca, F
A1  - Di Marco, A
A1  - Poutanen, J
A1  - Bachetti, M
A1  - Motta, SE
A1  - Papitto, A
A1  - Pilia, M
A1  - Xie, F
A1  - Bianchi, S
A1  - Bobrikova, A
A1  - Costa, E
A1  - Deng, W
A1  - Ge, MY
A1  - Illiano, G
A1  - Jia, SM
A1  - Krawczynski, H
A1  - Lai, EV
A1  - Liu, K
A1  - Mastroserio, G
A1  - Muleri, F
A1  - Rankin, J
A1  - Soffitta, P
A1  - Veledina, A
A1  - Ambrosino, F
A1  - Del Santo, M
A1  - Chen, W
A1  - Garcia, JA
A1  - Kaaret, P
A1  - Russell, TD
A1  - Wei, WH
A1  - Zhang, SN
A1  - Zuo, C
A1  - Arzoumanian, Z
A1  - Cocchi, M
A1  - Gnarini, A
A1  - Farinelli, R
A1  - Gendreau, K
A1  - Ursini, F
A1  - Weisskopf, MC
A1  - Zane, S
A1  - Agudo, I
A1  - Antonelli, LA
A1  - Baldini, L
A1  - Baumgartner, WH
A1  - Bellazzini, R
A1  - Bongiorno, SD
A1  - Bonino, R
A1  - Brez, A
A1  - Bucciantini, N
A1  - Capitanio, F
A1  - Castellano, S
A1  - Cavazzuti, E
A1  - Chen, CT
A1  - Ciprini, S
A1  - De Rosa, A
A1  - Del Monte, E
A1  - Di Gesu, L
A1  - Di Lalla, N
A1  - Donnarumma, I
A1  - Doroshenko, V
A1  - Dov?iak, M
A1  - Ehlert, SR
A1  - Enoto, T
A1  - Evangelista, Y
A1  - Fabiani, S
A1  - Ferrazzoli, R
A1  - Gunji, S
A1  - Hayashida, K
A1  - Heyl, J
A1  - Iwakiri, W
A1  - Jorstad, SG
A1  - Karas, V
A1  - Kislat, F
A1  - Kitaguchi, T
A1  - Kolodziejczak, JJ
A1  - Latronico, L
A1  - Liodakis, I
A1  - Maldera, S
A1  - Manfreda, A
A1  - Marin, F
A1  - Marinucci, A
A1  - Marscher, AP
A1  - Marshall, HL
A1  - Massaro, F
A1  - Matt, G
A1  - Mitsuishi, I
A1  - Mizuno, T
A1  - Negro, M
A1  - Ng, CY
A1  - O?Dell, SL
A1  - Omodei, N
A1  - Oppedisano, C
A1  - Pavlov, GG
A1  - Peirson, AL
A1  - Perri, M
A1  - Pesce-Rollins, M
A1  - Petrucci, PO
A1  - Possenti, A
A1  - Puccetti, S
A1  - Ramsey, BD
JF  - The Astrophysical Journal Letters
N1  - Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence, https://creativecommons.org/licenses/by/4.0/. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
VL  - 960
IS  - 2
N2  - The Imaging X-ray Polarimetry Explorer measured with high significance the X-ray polarization of the brightest Z-source, Sco X-1, resulting in the nominal 2?8 keV energy band in a polarization degree of 1.0% ± 0.2% and a polarization angle of 8° ± 6° at a 90% confidence level. This observation was strictly simultaneous with observations performed by NICER, NuSTAR, and Insight-HXMT, which allowed for a precise characterization of its broadband spectrum from soft to hard X-rays. The source has been observed mainly in its soft state, with short periods of flaring. We also observed low-frequency quasiperiodic oscillations. From a spectropolarimetric analysis, we associate a polarization to the accretion disk at <3.2% at 90% confidence level, compatible with expectations for an electron scattering dominated optically thick atmosphere at the Sco X-1 inclination of ?44°; for the higher-energy Comptonized component, we obtain a polarization of 1.3% ± 0.4%, in agreement with expectations for a slab of Thomson optical depth of ?7 and an electron temperature of ?3 keV. A polarization rotation with respect to previous observations by OSO-8 and PolarLight, and also with respect to the radio-jet position angle, is observed. This result may indicate a variation of the polarization with the source state that can be related to relativistic precession or a change in the corona geometry with the accretion flow.
ID  - discovery10186104
UR  - https://doi.org/10.3847/2041-8213/ad132d
TI  - Highly Significant Detection of X-Ray Polarization from the Brightest Accreting Neutron Star Sco X-1
SN  - 2041-8205
Y1  - 2024/01/10/
AV  - public
ER  -