发表机构
Sternberg Astronomical Institute, Lomonosov Moscow State University; Department of Physics, Lomonosov Moscow State University; The Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University; Theoretical Astrophysics, IAAT, University of Tübingen（列别捷夫天体物理研究所，莫斯科国立大学; 物理学系，莫斯科国立大学; 雷蒙德和贝弗利·萨克勒物理与天文学院，特拉维夫大学; 理论天体物理学，IAAT，蒂宾根大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文通过种群合成研究发现，仅约0.02%的孤立吸积中子星能形成吸积盘，这类盘吸积中子星在亮X射线源中较多，或可作为长周期射电暂现源。
AI 中文摘要
成熟的孤立中子星可从星际介质吸积物质，因湍流作用，吸积气体能拥有足够角动量，在致密天体周围形成盘。本文对银河系孤立中子星开展种群合成研究，专门追踪盘形成的可能性，盘形成通常要求致密天体的空间速度较低（≤40 km s⁻¹）。总体而言，弱磁场有利于盘形成，因为磁层占据的体积更小；即便磁场以约1.5 Gyr的特征时间指数衰减，针对几种实际的螺旋桨制动模型，我们发现仅很小比例的吸积体（低至约0.02%）能形成盘。不过，盘吸积的孤立中子星在最亮的源中相对较多，我们估计在X射线流量≥10⁻¹⁴ erg s⁻¹ cm⁻²时，这类天体的数量可达数百个。我们推测盘吸积的孤立中子星可通过电子回旋脉泽发射表现为长周期射电暂现源，并预测了其光谱及猝灭的临界条件。
英文摘要
Mature, isolated neutron stars can accrete from the interstellar medium. Due to turbulence, the accreted gas can have a substantial angular momentum and form a disc around the compact object. In this paper, we perform a population synthesis of isolated neutron stars in the Milky Way that specifically tracks the possibility of disc formation, which typically requires a low spatial velocity of the compact object ($\lesssim 40$ km s$^{-1}$). In general, weak magnetic fields favour disc formation as the magnetosphere occupies a smaller volume. Still, even in the case of fields decaying exponentially over a characteristic timescale of $\sim 1.5$ Gyr, we find that for several realistic models of propeller spin-down, only a small fraction of accretors (down to $\sim 0.02$ %) attain discs. However, disc-accreting isolated neutron stars are relatively numerous among the brightest sources. We estimate that their number can reach a few hundred at X-ray fluxes of $\gtrsim 10^{-14}$ erg s$^{-1}$ cm$^{-2}$. We speculate that disc-accreting isolated neutron stars can manifest as long-period radio transient sources via electron cyclotron maser emission, predicting spectra and critical conditions for quenching.
Comments21 pages, 6 figures, submitted to JHEAP
