The magnetic field of the solar wind near the Sun is very difficult to measure directly. Measurements of Faraday rotation of linearly polarized radio sources occulted by the solar wind provide a unique opportunity to estimate this magnetic field, and the technique has been widely used in the past. However Faraday rotation is a path integral of the product of electron density and the projection of the magnetic field on the path. The electron density near the Sun can be measured by several methods, but it is quite variable. Here we show that it is possible to measure the path integrated electron density and the Faraday rotation simultaneously at 6-10 $R_\odot$ using millisecond pulsars as the linearly polarized radio source. By analyzing the Faraday rotation measurements with and without the simultaneous electron density observations we show that these observations significantly improve the accuracy of the magnetic field estimates.
Do all millisecond pulsars share a common heritage?
低质量X射线双星系统中中子星毫秒脉动的发现证实了毫秒射电双星与低质量X射线双星系统之间的联系。从那时起,从LMXB产生毫秒射电双星,然后由于偶极辐射而自旋下降的过程被认为是毫秒射电双星的“标准进化”。然而,是否所有观测到的毫秒射电暴都可以由LMXB产生的问题直到现在还没有得到定量的解决。标准的演化过程产生的毫秒周期(P)和自旋下降速率(Pdot)并不完全独立。毫秒级射电望远镜可能达到的P-Pdot值受到联合约束。为了检验观测到的毫秒射电天体是否是毫秒X射线天体(MSXP)的明确后代,我们制作了一张概率图,它代表了标准模型下毫秒射电天体的预期分布。我们以超过95%的置信度表明,在标准模型的框架内,所观测到的毫秒X射线天体不能产生具有高磁场的最快旋转毫秒射电天体,例如PSR B 1937 +21。
In this paper, we have investigated the accreting millisecond X-ray pulsars, which are rapidly rotating neutron stars in low-mass X-ray binaries. These systems show coherent X-ray pulsations that arise when the accretion flow is magnetically channeled to the stellar surface. Here, we have developed the fundamental equations for an accretion disc around accreting millisecond X-ray pulsars in the presence of a dynamo generated magnetic fields in the inner part of the disc and we have also formulated the numerical method for the structure equations in the inner region of the disc and the highest …
On the connection between accreting X-ray and radio millisecond pulsars
多年来,人们已经认识到,在低质量X射线双星(LMXB)的质量转移的终端阶段应该导致吸积中子星的磁层膨胀,导致制动扭矩作用于旋转的脉冲星。因此,在发现射电毫秒双星(MSP)之后,这些双星如何在罗氏瓣退耦阶段(RLDP)之后保持其快速自旋就成了一个悖论(例如Ruderman et al. 1989)。在这里,我提出了一个解决这个所谓的“关断问题”,这是最近发现的结合二进制恒星演化模型与扭矩计算(陶里斯2012)。解决的办法是,在RLDP期间,脉冲星的自旋平衡被打破,因此它仍然是一个快速旋转的物体。我简要地讨论了这些发现,鉴于两个观察到的自旋分布在人口的吸积X射线毫秒双星(AXMSP)和无线电MSP。
The globular cluster Omega Centauri is the most massive and luminous cluster in the Galaxy. The $γ$-ray source FL8Y J1326.7$-$4729 is coincident with the core of the cluster, leading to speculation that hitherto unknown radio pulsars or annihilating dark matter may be present in the cluster core. Here we report on the discovery of five millisecond pulsars in Omega Centauri following observations with the Parkes radio telescope. Four of these pulsars are isolated with spin periods of 4.1, 4.2, 4.6 and 6.8 ms. The fifth has a spin period of 4.8 ms and is in an eclipsing binary system with an orb…