标题： 关于射电脉冲星 B1944+17 的长零点和短零点、模式和间歇脉冲辐射 显示英文标题

标题： On the long and short nulls, modes and interpulse emission of radio pulsar B1944+17

摘要： 我们对脉冲星B1944+17进行了单脉冲研究，其随机关闭态（nulls）几乎占到其脉冲的70%，并且通常发生在模式边界处。 当不在关闭态时，该脉冲星显示出四种明亮的辐射模式，其中三种表现出漂移子脉冲。 B1944+17显示一个弱回程脉冲，我们发现它相对于主脉冲的位置是频率无关的。 其辐射几乎100%偏振，其偏振角变化轨迹非常平缓且方向与主脉冲相反，并且大约三分之二的时间处于关闭态。 几何建模表明，这颗脉冲星是一个近乎对齐的旋转器，其α值仅为约2度——即其磁轴与自转轴如此接近地对齐，以至于其视线轨道始终在其锥状波束内。 该星的关闭态似乎有两种不同类别：长度小于约8个自转周期的关闭态似乎是伪关闭态——即由视线穿越锥状波束系统中的“空”区域产生；而较长的关闭态则似乎代表了脉冲星发射引擎的实际停止。 显示英文摘要

摘要： We present a single pulse study of pulsar B1944+17, whose non-random nulls dominate nearly 70% of its pulses and usually occur at mode boundaries. When not in the null state, this pulsar displays four bright modes of emission, three of which exhibit drifting subpulses. B1944+17 displays a weak interpulse whose position relative to the main pulse we find to be frequency independent. Its emission is nearly 100% polarized, its polarization-angle traverse is very shallow and opposite in direction to that of the main pulse, and it nulls approximately two-thirds of the time. Geometric modeling indicates that this pulsar is a nearly aligned rotator whose alpha value is hardly 2 degrees--i.e., its magnetic axis is so closely aligned with its rotation axis that its sightline orbit remains within its conal beam. The star's nulls appear to be of two distinct types: those with lengths less than about 8 rotation periods appear to be pseudonulls--that is, produced by "empty" sightline traverses through the conal beam system; whereas the longer nulls appear to represent actual cessations of the pulsar's emission engine.