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postgraduate thesis: X-ray observations of magnetar SGR 0501+4516 from outburst to quiescence
Title | X-ray observations of magnetar SGR 0501+4516 from outburst to quiescence |
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Authors | |
Advisors | |
Issue Date | 2017 |
Publisher | The University of Hong Kong (Pokfulam, Hong Kong) |
Citation | Mong, Y. [蒙亦麟]. (2017). X-ray observations of magnetar SGR 0501+4516 from outburst to quiescence. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. |
Abstract | Magnetars are neutron stars having extreme magnetic field strengths. Study of their emission properties in the quiescent state can help understand effects of a strong magnetic field on neutron stars. SGR 0501+4516 is a magnetar discovered in 2008 during an outburst and has recently returned to quiescence. I report its spectral and timing properties measured with new and archival observations from the Chandra X-Ray Observatory, XMM-Newton, and Suzaku. I found that the quiescent spectrum is best fit by a power-law plus two blackbody model, with temperatures of kT_low ∼ 0.25 keV and kT_high ∼ 0.61 keV and a photon index of Γ ∼ 3.2. I interpret these two blackbody components as emission from a hotspot and the entire surface. The hotspot radius shrinked from 1.5 km to 0.5 km since outburst and there is a significant correlation between its area and the X-ray luminosity, which well agrees with prediction by the twisted magnetosphere model.
I applied the two temperature spectral model to all magnetars in quiescence and found that it could be a common feature among the population. Moreover, the temperature of the cooler blackbody shows a general trend with the magnetar field strength, which supports the simple scenario of heating by magnetic field decay |
Degree | Master of Philosophy |
Subject | Magnetars X-ray astronomy |
Dept/Program | Physics |
Persistent Identifier | http://hdl.handle.net/10722/255411 |
DC Field | Value | Language |
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dc.contributor.advisor | Ng, SCY | - |
dc.contributor.advisor | Chau, HF | - |
dc.contributor.author | Mong, Yik-lun | - |
dc.contributor.author | 蒙亦麟 | - |
dc.date.accessioned | 2018-07-05T07:43:27Z | - |
dc.date.available | 2018-07-05T07:43:27Z | - |
dc.date.issued | 2017 | - |
dc.identifier.citation | Mong, Y. [蒙亦麟]. (2017). X-ray observations of magnetar SGR 0501+4516 from outburst to quiescence. (Thesis). University of Hong Kong, Pokfulam, Hong Kong SAR. | - |
dc.identifier.uri | http://hdl.handle.net/10722/255411 | - |
dc.description.abstract | Magnetars are neutron stars having extreme magnetic field strengths. Study of their emission properties in the quiescent state can help understand effects of a strong magnetic field on neutron stars. SGR 0501+4516 is a magnetar discovered in 2008 during an outburst and has recently returned to quiescence. I report its spectral and timing properties measured with new and archival observations from the Chandra X-Ray Observatory, XMM-Newton, and Suzaku. I found that the quiescent spectrum is best fit by a power-law plus two blackbody model, with temperatures of kT_low ∼ 0.25 keV and kT_high ∼ 0.61 keV and a photon index of Γ ∼ 3.2. I interpret these two blackbody components as emission from a hotspot and the entire surface. The hotspot radius shrinked from 1.5 km to 0.5 km since outburst and there is a significant correlation between its area and the X-ray luminosity, which well agrees with prediction by the twisted magnetosphere model. I applied the two temperature spectral model to all magnetars in quiescence and found that it could be a common feature among the population. Moreover, the temperature of the cooler blackbody shows a general trend with the magnetar field strength, which supports the simple scenario of heating by magnetic field decay | - |
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 | Magnetars | - |
dc.subject.lcsh | X-ray astronomy | - |
dc.title | X-ray observations of magnetar SGR 0501+4516 from outburst to quiescence | - |
dc.type | PG_Thesis | - |
dc.description.thesisname | Master of Philosophy | - |
dc.description.thesislevel | Master | - |
dc.description.thesisdiscipline | Physics | - |
dc.description.nature | published_or_final_version | - |
dc.identifier.doi | 10.5353/th_991044019380903414 | - |
dc.date.hkucongregation | 2018 | - |
dc.identifier.mmsid | 991044019380903414 | - |