2024ApJ...960L..11L

Query : 2024ApJ...960L..11L

2024ApJ...960L..11L - Astrophys. J., 960, L11 (2024/January-2)

Highly Significant Detection of X-Ray Polarization from the Brightest Accreting Neutron Star Sco X-1.

LA MONACA F., DI MARCO A., POUTANEN J., BACHETTI M., MOTTA S.E., PAPITTO A., PILIA M., XIE F., BIANCHI S., BOBRIKOVA A., COSTA E., DENG W., GE M.-Y., ILLIANO G., JIA S.-M., KRAWCZYNSKI H., LAI E.V., LIU K., MASTROSERIO G., MULERI F., RANKIN J., SOFFITTA P., VELEDINA A., AMBROSINO F., DEL SANTO M., CHEN W., GARCIA J.A., KAARET P., RUSSELL T.D., WEI W.-H., ZHANG S.-N., ZUO C., ARZOUMANIAN Z., COCCHI M., GNARINI A., FARINELLI R., GENDREAU K., URSINI F., WEISSKOPF M.C., ZANE S., AGUDO I., ANTONELLI L.A., BALDINI L., BAUMGARTNER W.H., BELLAZZINI R., BONGIORNO S.D., BONINO R., BREZ A., BUCCIANTINI N., CAPITANIO F., CASTELLANO S., CAVAZZUTI E., CHEN C.-T., CIPRINI S., 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., GUNJI S., HAYASHIDA K., HEYL J., IWAKIRI W., JORSTAD S.G., KARAS V., KISLAT F., KITAGUCHI T., KOLODZIEJCZAK J.J., LATRONICO L., LIODAKIS I., MALDERA S., MANFREDA A., MARIN F., MARINUCCI A., MARSCHER A.P., MARSHALL H.L., MASSARO F., MATT G., MITSUISHI I., MIZUNO T., NEGRO M., NG C.-Y., O'DELL S.L., OMODEI N., OPPEDISANO C., PAVLOV G.G., PEIRSON A.L., PERRI M., PESCE-ROLLINS M., PETRUCCI P.-O., POSSENTI A., PUCCETTI S., RAMSEY B.D., RATHEESH A., ROBERTS O.J., ROMANI R.W., 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. (The IXPE Collaboration)

Abstract (from CDS):

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.

Abstract Copyright: © 2024. The Author(s). Published by the American Astronomical Society.

Journal keyword(s): Polarimetry - Spectropolarimetry - Neutron stars - Accretion - Stellar accretion disks - Low-mass x-ray binary stars - X-ray telescopes

Simbad objects: 13

goto Full paper

goto View the references in ADS

Number of rows : 13
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 V* BR Cir HXB 15 20 40.8532547060 -57 10 00.206639033   21.4 21.4     B5-A0I 849 1
2 V* V818 Sco LXB 16 19 55.0692669024 -15 38 25.017666540 11.60 12.40 11.1     Oev 1730 0
3 4U 1642-45 LXB 16 45 48.1 -45 36 42           ~ 467 1
4 [KRL2007b] 214 LXB 17 00 58.46 -46 11 08.6           ~ 296 0
5 V* V1101 Sco LXB 17 05 44.4916006152 -36 25 23.049324480   20.10 18.6     ~ 473 0
6 V* V2216 Oph LXB 17 31 44.17 -16 57 40.9 16.40 17.10 16.8     ~ 329 1
7 4U 1758-25 LXB 18 01 09.7308060816 -25 04 44.120221284     11.08     ~ 705 1
8 V* NP Ser LXB 18 16 01.7 -14 02 09   18.8       K 683 2
9 X Sgr X-4 LXB 18 23 40.57 -30 21 40.6   19.06 18.81     ~ 1056 1
10 V* V4634 Sgr LXB 18 29 28.8 -23 47 48 18.90 19.40 19     ~ 399 0
11 HD 226868 HXB 19 58 21.6757355952 +35 12 05.784512688 9.38 9.72 8.91 8.42   O9.7Iabpvar 4590 0
12 V* V404 Cyg HXB 20 24 03.8247037434 +33 52 01.961154861           G9/K0III/V 1370 0
13 V* V1341 Cyg LXB 21 44 41.1544345272 +38 19 17.066570988 15.00 15.13 14.68 15.00   A9III 1229 1

To bookmark this query, right click on this link: simbad:objects in 2024ApJ...960L..11L and select 'bookmark this link' or equivalent in the popup menu