CaltechAUTHORS
Published May 2023 | Version public
Journal Article Metadata-only

Simultaneous space and phase resolved X-ray polarimetry of the Crab pulsar and nebula

Creators

  • 1. ROR icon Arcetri Astrophysical Observatory
  • 2. ROR icon University of Florence
  • 3. ROR icon INFN Sezione di Firenze
  • 4. ROR icon Institute for Space Astrophysics and Planetology
  • 5. ROR icon Osservatorio Astronomico di Cagliari
  • 6. ROR icon Stanford University
  • 7. ROR icon INFN Sezione di Pisa
  • 8. ROR icon RIKEN
  • 9. ROR icon Hiroshima University
  • 10. ROR icon Yamagata University
  • 11. ROR icon University of Pisa
  • 12. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 13. ROR icon Marshall Space Flight Center
  • 14. ROR icon Massachusetts Institute of Technology
  • 15. ROR icon Goddard Space Flight Center
  • 16. ROR icon University of Maryland, College Park
  • 17. ROR icon Deutsches Elektronen-Synchrotron DESY
  • 18. ROR icon Guangxi University
  • 19. ROR icon University of British Columbia
  • 20. ROR icon Instituto de Astrofísica de Andalucía
  • 21. ROR icon Astronomical Observatory of Rome
  • 22. ROR icon Agenzia Spaziale Italiana
  • 23. ROR icon Roma Tre University
  • 24. ROR icon INFN Sezione di Torino
  • 25. ROR icon University of Turin
  • 26. ROR icon Universities Space Research Association
  • 27. ROR icon INFN Sezione di Roma II
  • 28. ROR icon University of Tübingen
  • 29. ROR icon Astronomical Institute
  • 30. ROR icon University of New Hampshire
  • 31. ROR icon California Institute of Technology
  • 32. ROR icon Osaka University
  • 33. ROR icon Chiba University
  • 34. ROR icon Boston University
  • 35. ROR icon St Petersburg University
  • 36. ROR icon University of Iowa
  • 37. ROR icon Washington University in St. Louis
  • 38. ROR icon University of Turku
  • 39. ROR icon Observatory of Strasbourg
  • 40. ROR icon Nagoya University
  • 41. ROR icon University of Hong Kong
  • 42. ROR icon Pennsylvania State University
  • 43. ROR icon Institut de Planétologie et d'Astrophysique de Grenoble
  • 44. ROR icon Brera Astronomical Observatory
  • 45. ROR icon University of Padua
  • 46. ROR icon University of Rome Tor Vergata
  • 47. ROR icon University College London
  • 48. ROR icon University of Amsterdam

Abstract

The Crab pulsar and its nebula are among the most studied astrophysical systems, and constitute one of the most promising environments where high-energy processes and particle acceleration can be investigated. They are the only objects for which significant X-ray polarization was detected in the past. Here we present the Imaging X-ray Polarimetry Explorer (IXPE) observation of the Crab pulsar and nebula. The total pulsar pulsed emission in the [2–8] keV energy range is unpolarized. Significant polarization up to 15% is detected in the core of the main peak. The nebula has a total space integrated polarized degree of 20% and polarization angle of 145°. The polarized maps show a large variation in the local polarization, and regions with a polarized degree up to 45–50%. The polarization pattern suggests a predominantly toroidal magnetic field. Our findings for the pulsar are inconsistent with most inner magnetospheric models, and suggest emission is more likely to come from the wind region. For the nebula, the polarization map suggests a patchy distribution of turbulence, uncorrelated with the intensity, in contrast with simple expectations from numerical models.

Additional Information

© The Author(s), under exclusive licence to Springer Nature Limited 2023. The IXPE is a joint US and Italian mission. The US contribution is supported by NASA and led and managed by its Marshall Space Flight Center (MSFC), with industry partner Ball Aerospace (contract no. NNM15AA18C). The Italian contribution is supported by the Italian Space Agency (Agenzia Spaziale Italiana, ASI) through contract no. ASI-OHBI-2017-12-I.0, agreement nos. ASI-INAF-2017-12-H0 and ASI-INFN-2017.13-H0, and its Space Science Data Center (SSDC) with agreement nos. ASI-INAF-2022-14-HH.0 and ASI-INFN 2021-43-HH.0, and by the Istituto Nazionale di Astrofisica (INAF) and the Istituto Nazionale di Fisica Nucleare (INFN) in Italy. This research used data products provided by the IXPE Team (MSFC, SSDC, INAF and INFN) and distributed with additional software tools by the High-Energy Astrophysics Science Archive Research Center (HEASARC), at NASA Goddard Space Flight Center (GSFC). The research at Boston University was supported in part by National Science Foundation grant no. AST-2108622. Part of the French contributions is supported by the Scientific Research National Center (CNRS) and the French spatial agency (CNES). I.A. acknowledges financial support from the Spanish 'Ministerio de Ciencia e Innovación' (grant no. MCIN/AEI/ 10.13039/501100011033) through the Center of Excellence Severo Ochoa award for the Instituto de Astrofísica de Andalucía-CSIC (grant no. CEX2021-001131-S), and through grant nos. PID2019-107847RB-C44 and PID2022-139117NB-C44. C.-Y.N. is supported by a GRF grant from the Hong Kong Government under no. HKU 17305419. N.B. was supported by the INAF MiniGrant 'PWNnumpol - Numerical Studies of Pulsar Wind Nebulae in The Light of IXPE'. J.H. acknowledges support from the Natural Sciences and Engineering Research Council of Canada through a Discovery Grant, the Canadian Space Agency through the co-investigator grant programme, and computational resources and services provided by Compute Canada, Advanced Research Computing at the University of British Columbia, and the SciServer science platform. S.G. and E.W. were supported by grant nos. JSPS KAKENHI JP 19H00696 and 22K14068. Contributions. N.B. led the data analysis and the writing of the paper. R.F., M.B., J.R., L.P. and F.M. contributed to data analysis and data calibration. N.D.L., C.S., N.O., T.K., T.M., S.G. and E.W. contributed to data analysis and results interpretation. M.C.W., M.N., S.S., E.D.O.W., F.X., J.H., R.W.R., P.T., A.P. and H.L.M. contributed to text revision and data interpretation. L.B. and M.P.-R. contributed to software development. The remaining members of the IXPE collaboration contributed to the design of the mission, to the calibration of the instrument, to defining its science case and to the planning of the observations. All authors provided inputs and comments on the paper. Data availability. Data from the Crab PSR and nebula observation are available in the HEASARC IXPE Data Archive (https://heasarc.gsfc.nasa.gov/docs/ixpe/archive/). Additional data are available in the Supplementary Information and from figshare at https://doi.org/10.6084/m9.figshare.22203163. Source data are provided with this paper. Code availability. The ixpeobssim software and documentation can be downloaded at https://github.com/lucabaldini/ixpeobssim. Other information supporting the findings of this study, and specific data-reduction pipelines, are available from the corresponding author upon request. The authors declare no competing interests.

Additional details

Identifiers

Eprint ID
121582
Resolver ID
CaltechAUTHORS:20230526-436870000.28

Funding

NASA
NNM15AA18C
Agenzia Spaziale Italiana (ASI)
ASI-OHBI-2017-12-I.0
Agenzia Spaziale Italiana (ASI)
ASI-INAF-2017-12-H0
Agenzia Spaziale Italiana (ASI)
ASI-INFN-2017.13-H0
Agenzia Spaziale Italiana (ASI)
ASI-INAF-2022-14-HH.0
Agenzia Spaziale Italiana (ASI)
ASI-INFN 2021-43-HH.0
Istituto Nazionale di Astrofisica (INAF)
Istituto Nazionale di Fisica Nucleare (INFN)
NSF
AST-2108622
Centre National de la Recherche Scientifique (CNRS)
Ministerio de Ciencia e Innovación (MCIN)
MCIN/AEI/10.13039/501100011033
Centre National d'Études Spatiales (CNES)
Severo Ochoa Centre of Excellence
CEX2021-001131-S
Ministerio de Ciencia e Innovación (MCIN)
PID2019-107847RB-C44
Ministerio de Ciencia e Innovación (MCIN)
PID2022-139117NB-C44
Research Grants Council of Hong Kong
HKU 17305419
Natural Sciences and Engineering Research Council of Canada (NSERC)
Canadian Space Agency (CSA)
Compute Canada
Japan Society for the Promotion of Science (JSPS)
19H00696
Japan Society for the Promotion of Science (JSPS)
22K14068

Dates

Created
2023-07-10
Created from EPrint's datestamp field
Updated
2023-07-10
Created from EPrint's last_modified field

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