The radio pulsar population of the Small Magellanic Cloud

脉冲星脉冲射电辐射的过渡阶段及其与射电脉冲星消零的潜在关联

On the transition stage of pulsar pulsed radio emission and its potential association with radio pulsar nulling

本文基于内间隙模型将脉冲星磁层等效为RC电路，解释持续射电辐射到射电宁静之间的过渡阶段，并指出年老脉冲星会因延迟火花逐渐进入脉冲消零状态。

Radio efficiency of pulsars

We investigate radio emission efficiency $ξ$ of pulsars and report a near linear inverse correlation between $ξ$ and the spindown power $\dot E$, as well as a near linear correlation between $ξ$ and pulsar age $τ$. This is a consequence of very weak, if any, dependences of radio luminosity $L$ on pulsar period $P$ and period derivative $\dot{P}$, in contrast to X-ray or $γ$-ray emission luminosities. The analysis of radio fluxes suggests that these correlations are not due to a selection effect, but are intrinsic to the pulsar radio emission physics. We have found that, although with a large v…

Detection of radio emission from the gamma-ray pulsar J1732-3131 at 327 MHz

Although originally discovered as a radio-quiet gamma-ray pulsar, J1732-3131 has exhibited intriguing detections at decameter wavelengths. We report an extensive follow-up of the pulsar at 327 MHz with the Ooty radio telescope. Using the previously observed radio characteristics, and with an effective integration time of 60 hrs, we present a detection of the pulsar at a confidence level of 99.82%. The 327 MHz mean flux density is estimated to be 0.5-0.8 mJy, which establishes the pulsar to be a steep spectrum source and one of the least-luminous pulsars known to date. We also phase-aligned the…

辐照效应与带有巨星伴星的双星射电脉冲星

Irradiation effect and binary radio pulsars with giant companions

本文利用MESA恒星演化代码研究辐照效应对带有巨星伴星的双星射电脉冲星参数空间的影响，发现辐照可显著扩展其参数空间并可能使亚毫秒脉冲星伴有巨星伴星，为相关观测提供指导。

The Period-Width relationship for radio pulsars revisited

In the standard picture of radio pulsars, the radio emission arises from a set of open magnetic field lines, the extent of which is primarily determined by the pulsar's spin period, P, and the emission height. We have used a database of parameters from 600 pulsars to show that the observed profile width, W, follows W proportional to P^-0.3 albeit with a large scatter, emission occurs from heights below 400 km and that the beam is underfilled. Furthermore, the prevalence in the data for long period pulsars to have relatively wide profiles can only be explained if the angle between the magnetic …

Radio Searches for Pulsars and Short-Duration Transients

I discuss methods and current software packages for radio searches for pulsars and short-duration transients. I then describe the properties of the current pulsar population and the status of and predictions for ongoing and future surveys. The presently observed pulsar population numbers around 2000 and is expected to roughly double over the next five years, with the number of millisecond pulsars expected to more than triple. Finally, I discuss individual objects discovered in the Green Bank Telescope 350-MHz Drift-Scan Survey and the Arecibo Pulsar ALFA Survey.

Orbital eccentricity of binary radio pulsars in globular clusters and interaction between stars

We analyze the observed distribution of the orbital eccentricity and period of binary radio pulsars in globular clusters using computational tools to simulate binary-single star interactions. Globular clusters have different groups of pulsars arising from separate interaction scenarios. Intermediate eccentricities of cluster pulsars can be mostly accounted by fly-bys although locally lower stellar densities at pulsar positions may alter the situation. Very high eccentricities are likely to be results of exchanges and/or mergers of single stars with the binary companion of the pulsar.

The timing behaviour of radio pulsars

The purpose of this review paper is to summarise the pulsar timing method, to provide an overview of recent research into the spin-down of pulsars over decadal timescales and to highlight the science that can be achieved using high-precision timing of millisecond pulsars.

Are the infrared-faint radio sources pulsars?

Infrared-Faint Radio Sources (IFRS) are objects which are strong at radio wavelengths but undetected in sensitive Spitzer observations at infrared wavelengths. Their nature is uncertain and most have not yet been associated with any known astrophysical object. One possibility is that they are radio pulsars. To test this hypothesis we undertook observations of 16 of these sources with the Parkes Radio Telescope. Our results limit the radio emission to a pulsed flux density of less than 0.21 mJy (assuming a 50% duty cycle). This is well below the flux density of the IFRS. We therefore conclude t…

Constraining the Vela Pulsar's Radio Emission Region Using Nyquist-Limited Scintillation Statistics

Using a novel technique, we achieve ~100 picoarcsecond resolution and set an upper bound of less than 4 km for the characteristic size of the Vela pulsar's emission region. Specifically, we analyze flux-density statistics of the Vela pulsar at 760 MHz. Because the pulsar exhibits strong diffractive scintillation, these statistics convey information about the spatial extent of the radio emission region. We measure both a characteristic size of the emission region and the emission sizes for individual pulses. Our results imply that the radio emission altitude for the Vela pulsar at this frequenc…