Multiwavelength Pulsations and Surface Temperature Distribution in the Middle-aged Pulsar B1055–52
We present a detailed study of the X-ray emission from PSR B1055–52 using XMM-Newton observations from 2019 and 2000. The phase-integrated X-ray emission from this pulsar is poorly described by existing models of neutron star atmospheres. Instead, we confirm that, similar to other middle-aged pulsar...
| Main Authors: | , , , , , |
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| Format: | Journal article |
| Language: | English |
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American Astronomical Society
2024
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| _version_ | 1826314778305363968 |
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| author | Vahdat, A Posselt, B Pavlov, GG Weltevrede, P Santangelo, A Johnston, S |
| author_facet | Vahdat, A Posselt, B Pavlov, GG Weltevrede, P Santangelo, A Johnston, S |
| author_sort | Vahdat, A |
| collection | OXFORD |
| description | We present a detailed study of the X-ray emission from PSR B1055–52 using XMM-Newton observations from 2019 and 2000. The phase-integrated X-ray emission from this pulsar is poorly described by existing models of neutron star atmospheres. Instead, we confirm that, similar to other middle-aged pulsars, the best-fitting spectral model consists of two blackbody components, with substantially different temperatures and emitting areas, and a nonthermal component characterized by a power law. Our phase-resolved X-ray spectral analysis using this three-component model reveals variations in the thermal emission parameters with the pulsar’s rotational phase. These variations suggest a nonuniform temperature distribution across the neutron star’s surface, including the cold thermal component and probable hot spot(s). Such a temperature distribution can be caused by external and internal heating processes, likely a combination thereof. We observe very high pulse fractions, 60%–80% in the 0.7–1.5 keV range, dominated by the hot blackbody component. This could be related to temperature nonuniformity and potential beaming effects in an atmosphere. We find indication of a second hot spot that appears at lower energies (0.15–0.3 keV) than the first hot spot (0.5–1.5 keV) in the X-ray light curves and is offset by about half a rotation period. This finding aligns with the nearly orthogonal rotator geometry suggested by radio observations of this interpulse pulsar. If the hot spots are associated with polar caps, a possible explanation for their temperature asymmetry could be an offset magnetic dipole and/or an additional toroidal magnetic field component in the neutron star crust. |
| first_indexed | 2024-09-25T04:06:18Z |
| format | Journal article |
| id | oxford-uuid:06c550bd-4f52-4be5-aa43-a350848c52af |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:11:05Z |
| publishDate | 2024 |
| publisher | American Astronomical Society |
| record_format | dspace |
| spelling | oxford-uuid:06c550bd-4f52-4be5-aa43-a350848c52af2024-10-16T09:09:17ZMultiwavelength Pulsations and Surface Temperature Distribution in the Middle-aged Pulsar B1055–52Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:06c550bd-4f52-4be5-aa43-a350848c52afEnglishJisc Publications RouterAmerican Astronomical Society2024Vahdat, APosselt, BPavlov, GGWeltevrede, PSantangelo, AJohnston, SWe present a detailed study of the X-ray emission from PSR B1055–52 using XMM-Newton observations from 2019 and 2000. The phase-integrated X-ray emission from this pulsar is poorly described by existing models of neutron star atmospheres. Instead, we confirm that, similar to other middle-aged pulsars, the best-fitting spectral model consists of two blackbody components, with substantially different temperatures and emitting areas, and a nonthermal component characterized by a power law. Our phase-resolved X-ray spectral analysis using this three-component model reveals variations in the thermal emission parameters with the pulsar’s rotational phase. These variations suggest a nonuniform temperature distribution across the neutron star’s surface, including the cold thermal component and probable hot spot(s). Such a temperature distribution can be caused by external and internal heating processes, likely a combination thereof. We observe very high pulse fractions, 60%–80% in the 0.7–1.5 keV range, dominated by the hot blackbody component. This could be related to temperature nonuniformity and potential beaming effects in an atmosphere. We find indication of a second hot spot that appears at lower energies (0.15–0.3 keV) than the first hot spot (0.5–1.5 keV) in the X-ray light curves and is offset by about half a rotation period. This finding aligns with the nearly orthogonal rotator geometry suggested by radio observations of this interpulse pulsar. If the hot spots are associated with polar caps, a possible explanation for their temperature asymmetry could be an offset magnetic dipole and/or an additional toroidal magnetic field component in the neutron star crust. |
| spellingShingle | Vahdat, A Posselt, B Pavlov, GG Weltevrede, P Santangelo, A Johnston, S Multiwavelength Pulsations and Surface Temperature Distribution in the Middle-aged Pulsar B1055–52 |
| title | Multiwavelength Pulsations and Surface Temperature Distribution in the Middle-aged Pulsar B1055–52 |
| title_full | Multiwavelength Pulsations and Surface Temperature Distribution in the Middle-aged Pulsar B1055–52 |
| title_fullStr | Multiwavelength Pulsations and Surface Temperature Distribution in the Middle-aged Pulsar B1055–52 |
| title_full_unstemmed | Multiwavelength Pulsations and Surface Temperature Distribution in the Middle-aged Pulsar B1055–52 |
| title_short | Multiwavelength Pulsations and Surface Temperature Distribution in the Middle-aged Pulsar B1055–52 |
| title_sort | multiwavelength pulsations and surface temperature distribution in the middle aged pulsar b1055 52 |
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