摘要
The relation between the spin period and the orbital period in high-mass X-ray binaries is investigated.Be/X-ray binaries and SG/X-ray binaries occupy different areas in Corbet's diagram.The two SG/X-ray binaries,IGR J18483-0311 and OAO 1657-415,however,appear to occupy a transition region between Be/X-ray binaries and wind-fed SG/X-ray binaries.This can be understood by noting that the neutron stars in the two SG/X-ray binaries have not reached their equilibrium spin periods when the donors evolved off the main sequence.Here,we provide an alternative scenario to explain their location in Corbet's diagram:the SG/X-ray binaries are the descendants of Be/X-ray binaries,i.e.the supergiants in these systems were formed from O-type emission line stars instead of normal main-sequence stars.Furthermore,we suggest that there are two types of SG/X-ray binaries:one is directly evolved from a normal OB-type main sequence and neutron star system without an X-ray history,and the other evolved from a Be/X-ray binary with an X-ray history.
The relation between the spin period and the orbital period in high-mass X-ray binaries is investigated.Be/X-ray binaries and SG/X-ray binaries occupy different areas in Corbet’s diagram.The two SG/X-ray binaries,IGR J18483-0311 and OAO 1657-415,however,appear to occupy a transition region between Be/X-ray binaries and wind-fed SG/X-ray binaries.This can be understood by noting that the neutron stars in the two SG/X-ray binaries have not reached their equilibrium spin periods when the donors evolved off the main sequence.Here,we provide an alternative scenario to explain their location in Corbet’s diagram:the SG/X-ray binaries are the descendants of Be/X-ray binaries,i.e.the supergiants in these systems were formed from O-type emission line stars instead of normal main-sequence stars.Furthermore,we suggest that there are two types of SG/X-ray binaries:one is directly evolved from a normal OB-type main sequence and neutron star system without an X-ray history,and the other evolved from a Be/X-ray binary with an X-ray history.
作者
LIU QingZhong1,2,LI Hui1,3 & YAN JingZhi1,2 1 Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210008,China
2 Service d’Astrophysique,CEA Saclay and University Paris Diderot,91191 Gif-sur-Yvette,France
3 Graduate University of Chinese Academy of Sciences,Beijing 100049,China
基金
supported by the National Basic Research Program of China (Grant No. 2009CB824800)
the National High Technology Research and Development Program of China (Grant No. 2008AA12Z304)
the National Natural Science Foundation of China (Grant Nos. 10873036 and 10673032)
