A new small glitch in Vela discovered with a hidden Markov model
| العنوان: | A new small glitch in Vela discovered with a hidden Markov model |
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| المؤلفون: | L Dunn, A Melatos, C M Espinoza, D Antonopoulou, R Dodson |
| المصدر: | Monthly Notices of the Royal Astronomical Society. 522:5469-5478 |
| بيانات النشر: | Oxford University Press (OUP), 2023. |
| سنة النشر: | 2023 |
| مصطلحات موضوعية: | High Energy Astrophysical Phenomena (astro-ph.HE), Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - High Energy Astrophysical Phenomena |
| الوصف: | A striking feature of the Vela pulsar (PSR J0835$-$4510) is that it undergoes sudden increases in its spin frequency, known as glitches, with a fractional amplitude on the order of $10^{-6}$ approximately every 900 days. Glitches of smaller magnitudes are also known to occur in Vela. Their distribution in both time and amplitude is less well constrained but equally important for understanding the physical process underpinning these events. In order to better understand these small glitches in Vela, an analysis of high-cadence observations from the Mount Pleasant Observatory is presented. A hidden Markov model (HMM) is used to search for small, previously undetected glitches across 24 years of observations covering MJD 44929 to MJD 53647. One previously unknown glitch is detected around MJD 48636 (Jan 15 1992), with fractional frequency jump $\Delta f/f = (8.19 \pm 0.04) \times 10^{-10}$ and frequency derivative jump $\Delta\dot{f}/\dot{f} = (2.98 \pm 0.01) \times 10^{-4}$. Two previously reported small glitches are also confidently re-detected, and independent estimates of their parameters are reported. Excluding these events, 90% confidence frequentist upper limits on the sizes of missed glitches are also set, with a median upper limit of $\Delta f^{90\%}/f = 1.35 \times 10^{-9}$. Upper limits of this kind are enabled by the semi-automated and computationally efficient nature of the HMM, and are crucial to informing studies which are sensitive to the lower end of the glitch size distribution. Comment: 10 pages, 7 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society |
| تدمد: | 1365-2966 0035-8711 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a7f538c71c2f5bd042e3ec9b33107134Test https://doi.org/10.1093/mnras/stad1335Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....a7f538c71c2f5bd042e3ec9b33107134 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 13652966 00358711 |
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