Effects of the treatment of the mass quadrupole moment on ray-tracing applications for rapidly rotating neutron stars
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| Autores: | , |
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| Fecha de Publicación: | 2021 |
| Descripción: | The Neutron Star Interior Composition Explorer (NICER) mission has provided a unique opportunity to constrain the equation of state of neutron stars by using the technique of pulse-profile modelling. This technique requires accurate and efficient ray-tracing, that in turn requires a robust representation of the space–time around a neutron star. Several exact and approximate metrics have been proposed, and used, to perform ray-tracing around neutron stars, with both moderate and fast rotation. In this paper, we perform a comparison between several of these metrics, when used for ray-tracing. We calculate the shape of the neutron star as seen by a distant observer using two different surface formulae, the thermal spectrum and pulse profiles from circular and crescent-shaped hotspots, for four configurations of pulsars with rotation rates ranging from 622 to 1000 Hz, and using both a moderate and a stiff equation of state to include realistic and extreme cases. We find small differences between the metrics for rotation frequencies starting at that could theoretically be used for constraining the quadrupole moment or the space–time models. We also determine the practicality of use of each metric in larger-scale applications such as pulse-profile modelling. |
| País: | Kérwá |
| Institución: | Universidad de Costa Rica |
| Repositorio: | Kérwá |
| Lenguaje: | Inglés |
| OAI Identifier: | oai:kerwa.ucr.ac.cr:10669/105324 |
| Acceso en línea: | https://hdl.handle.net/10669/105324 https://doi.org/10.1093/mnras/stab1380 |
| Palabra clave: | gravitation methods: numerical stars: neutron pulsars: general X-rays: stars |