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postgraduate thesis: High-resolution radio study of the pulsar wind nebula MSH 15-52
Title | High-resolution radio study of the pulsar wind nebula MSH 15-52 |
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Authors | |
Advisors | |
Issue Date | 2018 |
Publisher | The University of Hong Kong (Pokfulam, Hong Kong) |
Citation | Leung, W. [梁偉恩]. (2018). High-resolution radio study of the pulsar wind nebula MSH 15-52. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. |
Abstract | Pulsar winds are charged particles accelerated by the extremely strong magnetic field of rotation-powered pulsars. When these particles interact with the ambient circumstellar or interstellar material (ISM) around the pulsar, they emit broadband synchrotron radiation. The interacting region formed a nebula which is collectively known as a pulsar wind nebula (PWN). A PWN could be formed by a young pulsar within a supernova remnant (SNR) or by a fast-moving pulsar which gives a bow shock nebula. Synchrotron radiation is the major emission mechanism of PWNe, which is in the range from radio to X-rays. In gamma-rays, the emission mechanism is inverse-Compton scattering of low-energy ambient photons. Young PWNe inside SNRs are often complex and features-rich astronomical objects, their morphology based on the evolution stage of the SNR.
We present a high-resolution radio imaging study of the PWN MSH 15-52 with new Australia Telescope Compact Array observations at 6 cm and 3 cm. The system is powered by a young and energetic radio pulsar B1509-58 with a high-spin down luminosity of E ~ 2 x 10^37 erg/s. Previous X-ray studies found a complex morphology for the PWN. The overall shape resembles a hand, extending over 10 pc with features like a bright collimated jet, double arcs, filaments and enhanced emission knots in the associated HII region RCW 89.
Unlike the X-ray emission which shows the most recent conditions of PWNe, radio emission has a much longer synchrotron loss timescale. This reflects the integrated history of the injected particles to the system. The new radio images discovered the long-sought radio PWN and show different morphology than the X-ray counterpart. No radio emission is detected at the X-ray jet position, instead an enhanced emission in a shape of sheath surrounds the jet which consists of a bright arc and polarised filaments. Polarisation measurements show that the intrinsic orientation of the magnetic field aligns with the X-ray jet elongation. Small-scale features include a narrow polarised filament across the pulsar, network of filaments and knots in RCW 89. Counterparts of X-ray features like the inner arc, the ``thumb'' are also discovered. The 6km correlation data were used to measure the position of B1509. The proper motion result could imply the pulsar is moving in the X-ray jet outflow direction. |
Degree | Doctor of Philosophy |
Subject | Pulsars Supernova remnants |
Dept/Program | Physics |
Persistent Identifier | http://hdl.handle.net/10722/261455 |
DC Field | Value | Language |
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dc.contributor.advisor | Ng, SCY | - |
dc.contributor.advisor | Chau, HF | - |
dc.contributor.author | Leung, Wai-yan | - |
dc.contributor.author | 梁偉恩 | - |
dc.date.accessioned | 2018-09-20T06:43:45Z | - |
dc.date.available | 2018-09-20T06:43:45Z | - |
dc.date.issued | 2018 | - |
dc.identifier.citation | Leung, W. [梁偉恩]. (2018). High-resolution radio study of the pulsar wind nebula MSH 15-52. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. | - |
dc.identifier.uri | http://hdl.handle.net/10722/261455 | - |
dc.description.abstract | Pulsar winds are charged particles accelerated by the extremely strong magnetic field of rotation-powered pulsars. When these particles interact with the ambient circumstellar or interstellar material (ISM) around the pulsar, they emit broadband synchrotron radiation. The interacting region formed a nebula which is collectively known as a pulsar wind nebula (PWN). A PWN could be formed by a young pulsar within a supernova remnant (SNR) or by a fast-moving pulsar which gives a bow shock nebula. Synchrotron radiation is the major emission mechanism of PWNe, which is in the range from radio to X-rays. In gamma-rays, the emission mechanism is inverse-Compton scattering of low-energy ambient photons. Young PWNe inside SNRs are often complex and features-rich astronomical objects, their morphology based on the evolution stage of the SNR. We present a high-resolution radio imaging study of the PWN MSH 15-52 with new Australia Telescope Compact Array observations at 6 cm and 3 cm. The system is powered by a young and energetic radio pulsar B1509-58 with a high-spin down luminosity of E ~ 2 x 10^37 erg/s. Previous X-ray studies found a complex morphology for the PWN. The overall shape resembles a hand, extending over 10 pc with features like a bright collimated jet, double arcs, filaments and enhanced emission knots in the associated HII region RCW 89. Unlike the X-ray emission which shows the most recent conditions of PWNe, radio emission has a much longer synchrotron loss timescale. This reflects the integrated history of the injected particles to the system. The new radio images discovered the long-sought radio PWN and show different morphology than the X-ray counterpart. No radio emission is detected at the X-ray jet position, instead an enhanced emission in a shape of sheath surrounds the jet which consists of a bright arc and polarised filaments. Polarisation measurements show that the intrinsic orientation of the magnetic field aligns with the X-ray jet elongation. Small-scale features include a narrow polarised filament across the pulsar, network of filaments and knots in RCW 89. Counterparts of X-ray features like the inner arc, the ``thumb'' are also discovered. The 6km correlation data were used to measure the position of B1509. The proper motion result could imply the pulsar is moving in the X-ray jet outflow direction. | - |
dc.language | eng | - |
dc.publisher | The University of Hong Kong (Pokfulam, Hong Kong) | - |
dc.relation.ispartof | HKU Theses Online (HKUTO) | - |
dc.rights | The author retains all proprietary rights, (such as patent rights) and the right to use in future works. | - |
dc.rights | This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. | - |
dc.subject.lcsh | Pulsars | - |
dc.subject.lcsh | Supernova remnants | - |
dc.title | High-resolution radio study of the pulsar wind nebula MSH 15-52 | - |
dc.type | PG_Thesis | - |
dc.description.thesisname | Doctor of Philosophy | - |
dc.description.thesislevel | Doctoral | - |
dc.description.thesisdiscipline | Physics | - |
dc.description.nature | published_or_final_version | - |
dc.identifier.doi | 10.5353/th_991044040582803414 | - |
dc.date.hkucongregation | 2018 | - |
dc.identifier.mmsid | 991044040582803414 | - |