Applying the timing tools of kilohertz quasi-periodic oscillations(kHz QPOs)and cross-correlations,we study the influence of the magnetosphere-disk relation on the X-ray radiation process of GX 17+2.First,as the spectral state track of X-ray emission evolves along the horizontal branch(HB),the magnetosphere-disk radii of the source derived by kHz QPOs shrink from r～24km to r～18 km,while its average X-ray intensities in≤10 keV and in≥10 keV show the opposite evolutional trends.Moreover,this branch has been detected with the anti-corre-lations between the low-/high-energy(e.g.,2-5 keV/16-30 keV)X-rays.We suggest that in HB there may exist an X-ray radiation transfer process at the disk radii near the neutron star(NS),i.e.,～5-10km away from the surface,which probably originates from the interaction between the corona or jet with high-energy X-rays and accretion disk with low-energy X-rays.Second,as the source evolves along the normal branch(NB)and along the flaring branch(FB),their average X-ray intensities in all～2-30keV show the monotonously decreasing and monotonously increasing trends,respectively.In addition,these two branches are both dominated by the positive correlations between the low-and high-energy(e.g.,2-5 keV/16-30 keV)X-rays.Moreover,the evolution along NB is accompanied by the shrinking of the magnetosphere-disk radii from r～18km to r～16 km.We ascribe these phenomena to that as the shrinking of the accretion disk radius,the piled up accretion matter around the NS surface may trigger the radiation that produces both the low-and high-energy X-rays simultaneously,and then form the branches of NB and FB.

De-Hua Wang;Cheng-Min Zhang;Ya-Juan Lei

School of Physics and Electronic Science,Guizhou Normal University,Guiyang 550001,China;CAS Key Laboratory of FAST,National Astronomical Observatories,Beijing 100101,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Radio Astronomy,Chinese Academy of Sciences,Beijing 100101,China;Key Laboratory of Solar Activity,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China

天文和天体物理学研究

[1]De-Hua Wang;Cheng-Min Zhang;Ya-Juan Lei-.Exploring the Accretion Disk Structure and X-ray Radiation of GX 17+2 Based on kHz QPOs and Cross-correlations)[J].天文和天体物理学研究,2022(12):239-248

17+2,QPOs,flaring,30keV,ascribe

Exploring,Accretion,Disk,Structure,Radiation,GX,Based,kHz,Cross,correlations,Applying,timing,tools,kilohertz,quasi,periodic,oscillations,cross,study,influence,magnetosphere,disk,radiation,process,First,spectral,state,track,emission,evolves,along,horizontal,HB,radii,source,derived,by,from,24km,while,its,average,intensities,show,opposite,evolutional,trends,Moreover,this,has,been,detected,anti,between,low,high,energy,rays,We,suggest,that,there,may,exist,transfer,near,neutron,star,NS,10km,away,surface,which,probably,originates,interaction,corona,jet,accretion,Second,normal,NB,FB,their,all,monotonously,decreasing,increasing,respectively,In,addition,these,two,branches,are,both,dominated,positive,accompanied,shrinking,18km,phenomena,radius,piled,up,matter,around,trigger,produces,simultaneously,then,form

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