1. Polarized x-rays constrain the disk-jet geometry in the black hole x-ray binary Cygnus X-1.
- Author
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Krawczynski H, Muleri F, Dovčiak M, Veledina A, Rodriguez Cavero N, Svoboda J, Ingram A, Matt G, Garcia JA, Loktev V, Negro M, Poutanen J, Kitaguchi T, Podgorný J, Rankin J, Zhang W, Berdyugin A, Berdyugina SV, Bianchi S, Blinov D, Capitanio F, Di Lalla N, Draghis P, Fabiani S, Kagitani M, Kravtsov V, Kiehlmann S, Latronico L, Lutovinov AA, Mandarakas N, Marin F, Marinucci A, Miller JM, Mizuno T, Molkov SV, Omodei N, Petrucci PO, Ratheesh A, Sakanoi T, Semena AN, Skalidis R, Soffitta P, Tennant AF, Thalhammer P, Tombesi F, Weisskopf MC, Wilms J, Zhang S, Agudo I, Antonelli LA, Bachetti M, Baldini L, Baumgartner WH, Bellazzini R, Bongiorno SD, Bonino R, Brez A, Bucciantini N, Castellano S, Cavazzuti E, Ciprini S, Costa E, De Rosa A, Del Monte E, Di Gesu L, Di Marco A, Donnarumma I, Doroshenko V, Ehlert SR, Enoto T, Evangelista Y, Ferrazzoli R, Gunji S, Hayashida K, Heyl J, Iwakiri W, Jorstad SG, Karas V, Kolodziejczak JJ, La Monaca F, Liodakis I, Maldera S, Manfreda A, Marscher AP, Marshall HL, Mitsuishi I, Ng CY, O'Dell SL, Oppedisano C, Papitto A, Pavlov GG, Peirson AL, Perri M, Pesce-Rollins M, Pilia M, Possenti A, Puccetti S, Ramsey BD, Romani RW, Sgrò C, Slane P, Spandre G, Tamagawa T, Tavecchio F, Taverna R, Tawara Y, Thomas NE, Trois A, Tsygankov S, Turolla R, Vink J, Wu K, Xie F, and Zane S
- Abstract
A black hole x-ray binary (XRB) system forms when gas is stripped from a normal star and accretes onto a black hole, which heats the gas sufficiently to emit x-rays. We report a polarimetric observation of the XRB Cygnus X-1 using the Imaging X-ray Polarimetry Explorer. The electric field position angle aligns with the outflowing jet, indicating that the jet is launched from the inner x-ray-emitting region. The polarization degree is 4.01 ± 0.20% at 2 to 8 kiloelectronvolts, implying that the accretion disk is viewed closer to edge-on than the binary orbit. These observations reveal that hot x-ray-emitting plasma is spatially extended in a plane perpendicular to, not parallel to, the jet axis.
- Published
- 2022
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