Identification and characterisation of the gamma-ray counterpart of the transitional pulsar candidate CXOU J110926.4-650224
Transitional millisecond pulsars (tMSPs) represent a crucial link between the rotation-powered and accretion-powered states of binary pulsars. During their active X-ray state, tMSPs are the only low-mass X-ray binary systems detected up to GeV energies by the Fermi Large Area Telescope (LAT). CXOU J...
| Autores: | , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/390984 |
| Acceso en línea: | http://hdl.handle.net/10261/390984 http://arxiv.org/abs/2502.18073v1 |
| Access Level: | acceso abierto |
| Palabra clave: | Accretion Accretion disks Methods: data analysis Stars: neutron X-rays: binaries X-rays: individuals: CXOU J110926.4-650224 |
| Sumario: | Transitional millisecond pulsars (tMSPs) represent a crucial link between the rotation-powered and accretion-powered states of binary pulsars. During their active X-ray state, tMSPs are the only low-mass X-ray binary systems detected up to GeV energies by the Fermi Large Area Telescope (LAT). CXOU J110926.4–650224 is a newly discovered tMSP candidate in an active X-ray state and is potentially spatially compatible with a faint gamma-ray source listed in the latest Fermi-LAT point-source catalogue as 4FGL J1110.3–6501. Confirming the association between CXOU J110926.4–650224 and the Fermi source is a key step towards validating its classification as a tMSP. We analysed Fermi-LAT data collected from August 2008 to June 2023 to determine a more accurate localisation of the gamma-ray source, characterise its spectral properties, and investigate potential time variability. By thoroughly reconstructing the gamma-ray background around the source using a weighted likelihood model, we obtain a new localisation that aligns with the position of the X-ray source at the 95% confidence level, with a test statistic value of ∼42. This establishes a spatial association between the gamma-ray source and CXOU J110926.4–650224. The gamma-ray emission is adequately described by a power-law model with a photon index of Γ = 2.5 ± 0.1 and a corresponding flux of (3.7 ± 0.9)×10−12 erg cm−2 s−1 in the 0.1–300 GeV range. |
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