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Neutron star X-ray binaries with MeerKAT
X-ray binaries make up a large fraction of transient systems. These soucres are categorized into black hole and neutron star systems based on the compact object. The dichotomy between neutron star X-ray binaries and black hole X-ray binaries was well established up to the early 2000s. However, the f...
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| Format: | Thesis |
| Language: | English |
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Department of Astronomy
2026
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| _version_ | 1869483645308239872 |
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| access_status_str | Open Access |
| author | Gasealahwe, Kelebogile |
| author2 | Monageng, Itumeleng |
| author_browse | Gasealahwe, Kelebogile Monageng, Itumeleng |
| author_facet | Monageng, Itumeleng Gasealahwe, Kelebogile |
| author_sort | Gasealahwe, Kelebogile |
| collection | Thesis |
| description | X-ray binaries make up a large fraction of transient systems. These soucres are categorized into black hole and neutron star systems based on the compact object. The dichotomy between neutron star X-ray binaries and black hole X-ray binaries was well established up to the early 2000s. However, the fundamental differences have come into question since the correlation between the radio continuum and X-ray waveband of an increasing amount of neutron stars systems revealed parallel trends to the black hole counterparts. In this study we make use of a sample set of low-mass neutron star X-ray binary systems to investigate the nature of the disc (X ray) and the jet (radio) activity during outburst events. The sample includes SAX J1808.4-3658 an Accreting millisecond pulsar, two transitional Z/Atoll-sources Cir X-1 and XTE J1701-462 and Z-sources Cyg X-2, GX 340+0, GX 17+2, GX 13+1 and GX 349+2. To investigate the disc and jet activity the sources were observed with radio telescopes MeerKAT and AMI and X-ray telescopes Swift-XRT, MAXI and NICER. SAX J1808.4 3658, Cir X-1 and XTE J1701-462 were observed for the full outbursts in 2019, 2021 and 2022/23 respectively. The group of Z-sources only had single observations made in 2021. The outbursts were analysed through radio imaging and examining the lightcurves. Radio flaring events were identified in the lighcurves and the minimum energy of these flares calculated for XTE J1701-462. On the other hand, for Cir X-1, the minimum energy was calculated for the nebula by measuring the size of the structure directly from the radio image. The Cir X-1 image is a deep field L-band radio image, through which we discovered the jets breaking out of the natal supernova remnant in the structure the nebula revealed. By placing the sources on the radio– X-ray our results suggest that some neutron star X-ray binaries follow a similar trend (slope of the plane) as black hole X-ray binaries. Therefore, the physical nature of the compact object may not play a significant role in the relationship of the jet production and the accretion disc of X-ray binaries. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/43330 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-07-01T04:02:17.472Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2026 |
| publishDateRange | 2026 |
| publishDateSort | 2026 |
| publisher | Department of Astronomy |
| publisherStr | Department of Astronomy |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/43330 Neutron star X-ray binaries with MeerKAT Gasealahwe, Kelebogile Monageng, Itumeleng Woudt, Patrick X-ray binaries X-ray binaries make up a large fraction of transient systems. These soucres are categorized into black hole and neutron star systems based on the compact object. The dichotomy between neutron star X-ray binaries and black hole X-ray binaries was well established up to the early 2000s. However, the fundamental differences have come into question since the correlation between the radio continuum and X-ray waveband of an increasing amount of neutron stars systems revealed parallel trends to the black hole counterparts. In this study we make use of a sample set of low-mass neutron star X-ray binary systems to investigate the nature of the disc (X ray) and the jet (radio) activity during outburst events. The sample includes SAX J1808.4-3658 an Accreting millisecond pulsar, two transitional Z/Atoll-sources Cir X-1 and XTE J1701-462 and Z-sources Cyg X-2, GX 340+0, GX 17+2, GX 13+1 and GX 349+2. To investigate the disc and jet activity the sources were observed with radio telescopes MeerKAT and AMI and X-ray telescopes Swift-XRT, MAXI and NICER. SAX J1808.4 3658, Cir X-1 and XTE J1701-462 were observed for the full outbursts in 2019, 2021 and 2022/23 respectively. The group of Z-sources only had single observations made in 2021. The outbursts were analysed through radio imaging and examining the lightcurves. Radio flaring events were identified in the lighcurves and the minimum energy of these flares calculated for XTE J1701-462. On the other hand, for Cir X-1, the minimum energy was calculated for the nebula by measuring the size of the structure directly from the radio image. The Cir X-1 image is a deep field L-band radio image, through which we discovered the jets breaking out of the natal supernova remnant in the structure the nebula revealed. By placing the sources on the radio– X-ray our results suggest that some neutron star X-ray binaries follow a similar trend (slope of the plane) as black hole X-ray binaries. Therefore, the physical nature of the compact object may not play a significant role in the relationship of the jet production and the accretion disc of X-ray binaries. 2026-06-18T06:35:18Z 2026-06-18T06:35:18Z 2026 2026-06-18T06:30:57Z Thesis / Dissertation Doctoral PhD http://hdl.handle.net/11427/43330 eng application/pdf Department of Astronomy Faculty of Science University of Cape Town |
| spellingShingle | X-ray binaries Gasealahwe, Kelebogile Neutron star X-ray binaries with MeerKAT |
| thesis_degree_str | Doctoral |
| title | Neutron star X-ray binaries with MeerKAT |
| title_full | Neutron star X-ray binaries with MeerKAT |
| title_fullStr | Neutron star X-ray binaries with MeerKAT |
| title_full_unstemmed | Neutron star X-ray binaries with MeerKAT |
| title_short | Neutron star X-ray binaries with MeerKAT |
| title_sort | neutron star x ray binaries with meerkat |
| topic | X-ray binaries |
| url | http://hdl.handle.net/11427/43330 |
| work_keys_str_mv | AT gasealahwekelebogile neutronstarxraybinarieswithmeerkat |