Detection of nearly periodic spin period reversals in Vela X-1 on long time-scales: inkling of solar-like cycle in the donor star?
| Autor: | P. C. Agrawal, Manojendu Choudhury, Jayashree Roy, Amar Deo Chandra |
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| Přispěvatelé: | UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai, Vidyanagari Campus, Kalina, Santacruz (East), Mumbai, Maharashtra 400098, India, Center of Excellence in Space Sciences India, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India, Inter-University Center for Astronomy and Astrophysics, Post Bag 4, Pune, Maharashtra 411007, India, Senior Professor (retired), Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Babha Road, Mumbai 400005, Maharashtra, India, Department of Physics, St. Xavier’s College, 5 Mahapalika Marg, Mumbai 400001, Maharashtra, India |
| Rok vydání: | 2021 |
| Předmět: |
Period (periodic table)
Astrophysics::High Energy Astrophysical Phenomena Massive star FOS: Physical sciences Astrophysics Star (graph theory) Stellar Winds Vela 01 natural sciences neutron stars Pulsar 0103 physical sciences Accretion Models Variation (astronomy) 010303 astronomy & astrophysics Spin-½ Stellar activity Physics X-ray pulsar High Energy Astrophysical Phenomena (astro-ph.HE) Accretion (meteorology) [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] 010308 nuclear & particles physics [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE] Astronomy and Astrophysics Accretion physics X-rays binaries Neutron star Space and Planetary Science Vela X-1 Condensed Matter::Strongly Correlated Electrons Astrophysics - High Energy Astrophysical Phenomena Accretion discs Timing Analysis |
| Zdroj: | Monthly Notices of the Royal Astronomical Society Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, In press |
| ISSN: | 0035-8711 1365-2966 |
| DOI: | 10.48550/arxiv.2108.07097 |
| Popis: | We explore the long-term evolution of the spin period of the High Mass X-ray Binary (HMXB) pulsar Vela X-1 over a period of 46 yr. Our analysis indicates nearly periodic variations in the spin period of the pulsar on time-scales of about 5.9 yr. There is suggestion of an overall spin-down behaviour of the pulsar though it is noticed that the source appears to stay near its equilibrium period 283.4 s since MJD 51000, with rather erratic spin-up/spin-down episodes around this value. Our study suggests nearly cyclic turnover in the spin behaviour of the pulsar from spin-up to spin-down regimes on time-scales of about 17-19 yr. To our knowledge this is the first report of periodic variation in the spin behaviour of a wind-fed accreting pulsar. We also observe erratic episodes of spin-up and spin-down behaviour on relatively shorter time-scales which is a well known archetype of this wind-fed X-ray pulsar. We investigate whether nearly periodic long-term spin period changes in the pulsar can be explained by using known mechanisms of torque reversals in the accretion powered neutron stars. It appears that changes in the accretion environment of the pulsar using current ideas can probably lead to long-term spin period changes in this X-ray pulsar. Comment: 15 pages, 7 figures, Accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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