Issue |
A&A
Volume 678, October 2023
|
|
---|---|---|
Article Number | A119 | |
Number of page(s) | 10 | |
Section | Stellar structure and evolution | |
DOI | https://doi.org/10.1051/0004-6361/202346994 | |
Published online | 12 October 2023 |
X-ray polarimetry of the accreting pulsar GX 301−2
1
Institut für Astronomie und Astrophysik, Universität Tübingen, Sand 1, 72076 Tübingen, Germany
e-mail: suleimanov@astro.uni-tuebingen.de
2
Department of Physics and Astronomy, 20014 University of Turku, Finland
3
INAF Istituto di Astrofisica e Planetologia Spaziali, Via del Fosso del Cavaliere 100, 00133 Roma, Italy
4
Institut de Recherche en Astrophysique et Planétologie, UPS-OMP, CNRS, CNES, 9 avenue du Colonel Roche, BP 44346, 31028 Toulouse Cedex 4, France
5
University of British Columbia, Vancouver, BC, V6T 1Z4
Canada
6
Space Research Institute (IKI) of Russian Academy of Sciences, Prosoyuznaya ul 84/32, 117997 Moscow, Russian Federation
7
International Space Science Institute, Hallerstrasse 6, 3012 Bern, Switzerland
8
Astrophysics, Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH
UK
9
National Research University Higher School of Economics, Faculty of Physics, 101000 Myasnitskaya ul. 20, Moscow, Russia
10
Instituto de Astrofísicade Andalucía – CSIC, Glorieta de la Astronomía s/n, 18008 Granada, Spain
11
INAF Osservatorio Astronomico di Roma, Via Frascati 33, 00040 Monte Porzio Catone (RM), Italy
12
Space Science Data Center, Agenzia Spaziale Italiana, Via del Politecnico snc, 00133 Roma, Italy
13
INAF Osservatorio Astronomico di Cagliari, Via della Scienza 5, 09047 Selargius (CA), Italy
14
Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa, Italy
15
Dipartimento di Fisica, Università di Pisa, Largo B. Pontecorvo 3, 56127 Pisa, Italy
16
NASA Marshall Space Flight Center, Huntsville, AL, 35812
USA
17
Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, via della Vasca Navale 84, 00146 Roma, Italy
18
Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Via Pietro Giuria 1, 10125 Torino, Italy
19
Dipartimento di Fisica, Università degli Studi di Torino, Via Pietro Giuria 1, 10125 Torino, Italy
20
INAF Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy
21
Dipartimento di Fisica e Astronomia, Università degli Studi di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (FI), Italy
22
Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, Via Sansone 1, 50019 Sesto Fiorentino (FI), Italy
23
Agenzia Spaziale Italiana, Via del Politecnico snc, 00133 Roma, Italy
24
Science and Technology Institute, Universities Space Research Association, Huntsville, AL, 35805
USA
25
Istituto Nazionale di Fisica Nucleare, Sezione di Roma “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Roma, Italy
26
Department of Physics and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, California, 94305
USA
27
Université Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
28
Astronomical Institute of the Czech Academy of Sciences, Bočnń II 1401/1, 14100 Praha 4, Czech Republic
29
RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198
Japan
30
Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA, 91125
USA
31
Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata-shi, 990-8560
Japan
32
Osaka University, 1-1 Yamadaoka, Suita, Osaka, 565-0871
Japan
33
International Center for Hadron Astrophysics, Chiba University, Chiba, 263-8522
Japan
34
Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA, 02215
USA
35
Department of Astrophysics, St. Petersburg State University, Universitetsky pr. 28, Petrodvoretz, 198504 St. Petersburg, Russia
36
Department of Physics and Astronomy and Space Science Center, University of New Hampshire, Durham, NH, 03824
USA
37
Physics Department and McDonnell Center for the Space Sciences, Washington University in St. Louis, St. Louis, MO, 63130
USA
38
Finnish Centre for Astronomy with ESO, 20014 University of Turku, Finland
39
Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Strada Comunale Cinthia, 80126 Napoli, Italy
40
Université de Strasbourg, CNRS, Observatoire Astronomique de Strasbourg, UMR 7550, 67000 Strasbourg, France
41
MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139
USA
42
Graduate School of Science, Division of Particle and Astrophysical Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602
Japan
43
Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8526
Japan
44
University of Maryland, Baltimore County, Baltimore, MD, 21250
USA
45
NASA Goddard Space Flight Center, Greenbelt, MD, 20771
USA
46
Center for Research and Exploration in Space Science and Technology, NASA/GSFC, Greenbelt, MD, 20771
USA
47
Department of Physics, University of Hong Kong, Pokfulam, Hong Kong
48
Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA, 16801
USA
49
Center for Astrophysics, Harvard & Smithsonian, 60 Garden St, Cambridge, MA, 02138
USA
50
INAF Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate (LC), Italy
51
Dipartimento di Fisica e Astronomia, Università degli Studi di Padova, Via Marzolo 8, 35131 Padova, Italy
52
Dipartimento di Fisica, Università degli Studi di Roma “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Roma, Italy
53
Department of Astronomy, University of Maryland, College Park, Maryland, 20742
USA
54
Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey, RH5 6NT
UK
55
Anton Pannekoek Institute for Astronomy & GRAPPA, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
56
Guangxi Key Laboratory for Relativistic Astrophysics, School of Physical Science and Technology, Guangxi University, Nanning, 530004
PR China
Received:
24
May
2023
Accepted:
3
August
2023
The phase- and energy-resolved polarization measurements of accreting X-ray pulsars (XRPs) allow us to test different theoretical models of their emission, and they also provide an avenue to determine the emission region geometry. We present the results of the observations of the XRP GX 301−2 performed with the Imaging X-ray Polarimetry Explorer (IXPE). A persistent XRP, GX 301−2 has one of the longest spin periods known: ∼680 s. A massive hyper-giant companion star Wray 977 supplies mass to the neutron star via powerful stellar winds. We did not detect significant polarization in the phase-averaged data when using spectro-polarimetric analysis, with the upper limit on the polarization degree (PD) of 2.3% (99% confidence level). Using the phase-resolved spectro-polarimetric analysis, we obtained a significant detection of polarization (above 99% confidence level) in two out of nine phase bins and a marginal detection in three bins, with a PD ranging between ∼3% and ∼10% and a polarization angle varying in a very wide range from ∼0° to ∼160°. Using the rotating vector model, we obtained constraints on the pulsar geometry using both phase-binned and unbinned analyses, finding excellent agreement. Finally, we discuss possible reasons for a low observed polarization in GX 301−2.
Key words: magnetic fields / methods: observational / polarization / stars: neutron / X-rays: binaries / X-rays: individuals: GX 301-2
© The Authors 2023
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This article is published in open access under the Subscribe to Open model. Subscribe to A&A to support open access publication.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.