On the lack of X-ray pulsation in most neutron star low-mass X-ray binaries

Author:

Niang N1ORCID,Ertan Ü1ORCID,Gençali A A1ORCID,Toyran O2,Ulubay A3,Devlen E4ORCID,Alpar M A1ORCID,Gügercinoğlu E5

Affiliation:

1. Faculty of Engineering and Natural Sciences, Sabancı University , Orhanlı, Tuzla, İstanbul 34956 , Turkey

2. Merdivenköy mah., Hızır Reis sok. , Kadıköy, İstanbul 34732 , Turkey

3. Faculty of Science, Department of Physics, Istanbul University , Vezneciler, İstanbul 34134 , Turkey

4. Faculty of Science, Department of Astronomy and Space Sciences, Ege University , Bornova, İzmir 35100 , Turkey

5. National Astronomical Observatories, Chinese Academy of Sciences , 20A Datun Road, Chaoyang District, Beijing 100101 , China

Abstract

ABSTRACT We have investigated whether the lack of X-ray pulsations from most neutron star (NS) low-mass X-ray binaries (LMXBs) could be due to the extension of their inner disc to the NS surface. To estimate the inner disc radii, we have employed the model, recently proposed to account for the torque reversals of LMXBs. In this model, the inner disc radius depends on the spin period as well as the dipole moment and the mass inflow rate of the disc. Our model results indicate that most LMXBs have mass accretion rates above the minimum critical rates required for the inner disc to reach down to the NS surface and thereby quench the pulsed X-ray emission. For most sources X-ray pulsations are allowed when the period decreases below a certain critical value. For the same parameters, the model is also consistent with the observed X-ray luminosity ranges of the individual accreting millisecond X-ray pulsars (AMXPs). The paucity of AMXPs compared to the majority population of non-pulsing LMXBs is explained, as well as the fact that AMXPs are transient sources.

Funder

Sabancı University

TÜBİTAK

National Natural Science Foundation of China

Publisher

Oxford University Press (OUP)

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3