{"title":"CONSTRAINING PARAMETERS OF MAGNETIC FIELD DECAY FOR ACCRETING ISOLATED NEUTRON STARS","authors":"S. Popov, M. Prokhorov","doi":"10.1080/01422410108228807","DOIUrl":null,"url":null,"abstract":"The influence of exponential magnetic field decay (MFD) on the spin evolution of isolated neutron stars is studied. The ROSAT observations of several X-ray sources, which can be accreting old isolated neutron stars, are used to constrain the exponential and power-law decay parameters. We show that for the exponential decay the ranges of minimum value of magnetic moment, b, and the characteristic decay time, td, 10 29.5 b 10 28 Gc m 3 ,10 8 td 10 7 yrs are excluded assuming the standard initial magnetic moment, 0a10 30 Gc m 3 . For these parameters, neutron stars would never reach the stage of accretion from the interstellar medium even for a low space velocity of the stars and a high density of the ambient plasma. The range of excluded parameters increases for lower values of 0. We also show, that, contrary to exponential MFD, no significant restrictions can be made for the parameters of power-law decay from the statistics of isolated neutron star candidates in ROSAT observations. Isolated neutron stars with constant magnetic fields and initial values of them less than 010 29 Gc m 3 never come to the stage of accretion. We briefly discuss the fate of old magnetars with and without MFD, and describe parameters of old accreting magnetars.","PeriodicalId":264948,"journal":{"name":"Surveys in High Energy Physics","volume":"28 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2000-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Surveys in High Energy Physics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1080/01422410108228807","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 4
Abstract
The influence of exponential magnetic field decay (MFD) on the spin evolution of isolated neutron stars is studied. The ROSAT observations of several X-ray sources, which can be accreting old isolated neutron stars, are used to constrain the exponential and power-law decay parameters. We show that for the exponential decay the ranges of minimum value of magnetic moment, b, and the characteristic decay time, td, 10 29.5 b 10 28 Gc m 3 ,10 8 td 10 7 yrs are excluded assuming the standard initial magnetic moment, 0a10 30 Gc m 3 . For these parameters, neutron stars would never reach the stage of accretion from the interstellar medium even for a low space velocity of the stars and a high density of the ambient plasma. The range of excluded parameters increases for lower values of 0. We also show, that, contrary to exponential MFD, no significant restrictions can be made for the parameters of power-law decay from the statistics of isolated neutron star candidates in ROSAT observations. Isolated neutron stars with constant magnetic fields and initial values of them less than 010 29 Gc m 3 never come to the stage of accretion. We briefly discuss the fate of old magnetars with and without MFD, and describe parameters of old accreting magnetars.
研究了指数磁场衰减(MFD)对孤立中子星自旋演化的影响。ROSAT对几个x射线源的观测,这些x射线源可以吸积古老的孤立中子星,用来约束指数和幂律衰变参数。我们发现,对于指数衰减,磁矩的最小值b和特征衰减时间td, 10 29.5 b 10 28 Gc m 3,10 8 d 10 7年,假设标准初始磁矩为0a10 30 Gc m 3,则不包括在指数衰减范围内。根据这些参数,即使中子星的空间速度很低,周围等离子体密度很高,中子星也永远不会达到从星际介质吸积的阶段。当值为0时,排除的参数范围会增大。我们还表明,与指数MFD相反,ROSAT观测中孤立中子星候选者的统计数据对幂律衰减参数没有明显的限制。孤立的中子星磁场恒定,初始值小于010 29 Gc m3,永远不会进入吸积阶段。我们简要地讨论了有和没有MFD的老磁星的命运,并描述了老吸积磁星的参数。