[论文解读] Magnetar counterparts, kinematics and birth sites with HST and JWST

A. A. Chrimes, J. D. Lyman+8 more|arXiv (Cornell University)|Mar 16, 2026

Pulsars and Gravitational Waves Research被引用 0

一句话总结

该研究利用 HST 和 JWST 识别新的近红外磁星对应对象，测量它们的自行与运动，并分析它们的出生位置和速度，以比较磁星运动学与更广泛的年轻中子星群体。

ABSTRACT

Magnetars are highly magnetised, isolated neutron stars with uncertain formation channels. They comprise a potentially significant fraction of the young neutron star population in the Milky Way, and are implicated in the explosion mechanisms of some of the most powerful explosions in nature. We aim to identify magnetars in the near-infrared with Hubble Space Telescope (HST) and James Webb Space Telescope (JWST) imaging, in order to measure their proper motions and search for their birth sites. Candidate infrared counterparts are selected based on variability, colours and proper motions which are outliers with respect to other sources in the field. Precise proper motions are obtained by tying HST/WCF3 and JWST/NIRcam images to the Gaia reference frame. We newly identify counterpart candidates for PSRJ1622-4950, 1RXSJ 170849.0-400910 and CXOUJ164710.2-455216. The past trajectory of the 1RXSJ 170849.0-400910-associated source coincides with the supernova remnant G346.6-0.2. The transverse velocity distribution of magnetars is found to be marginally inconsistent with young pulsars, due primarily to a dearth of high velocity magnetars. A candidate birth site is identified inside the cone of possible past trajectories in nearly every case. We show, based on the inferred kinematic ages, that characteristic ages may frequently be lower than the true age, but caution that this depends on the reliability of the birth site associations. We conclude that magnetars are similar in terms of their kinematics and birth sites to the wider Galactic neutron star population, consistent with magnetar formation being a common outcome of massive star core-collapse. However, tentative evidence for a dearth of high-velocity magnetars is emerging. If real, this may arise from physical differences in the progenitor population giving rise to magnetars, or from differences in their post-formation velocity evolution.

研究动机与目标

• 通过太空成像（HST 与 JWST）识别磁星的近红外对应对象。
• 通过与 Gaia 天区测量联动，获得精确的自行和横向速度。
• 追溯运动，识别可能的出生地（SNR、星团），并推断运动学年龄。
• 将磁星运动学和出生地分布与银河系内更广泛的年轻中子星群体进行比较。
• 基于运动学分析，评估磁星形成途径（化石磁场与发根动力学发）及形成后的演化对运动学的意味。

提出的方法

• 在 HST/WFC3-IR 数据上使用 dolphot 进行光度测量；用各滤波器的偏移将 Vega 度量转化为 AB 度量。
• 以 Gaia DR3 为锚定的天体测量；将 Gaia 位置转换到仪器坐标系并解全球天文测量解以获得绝对自行。
• 通过要求自行、颜色或变异性相对于野外群体为离群值（3σ 或 2σ 标准）来识别对应候选对象。
• 使用多历元的 HST（CXOU J164710.2-455216 使用 JWST）来推导与银河自转和局部静止参考系相关的特异自行。
• 将 X 射线误差圆与近红外源进行交叉匹配，并通过运动学、变异性及颜色来评估以确立候选对应对象。

Figure 1: HST cutouts with magnetar 3 $\sigma$ X-ray localisations indicated by blue dashed circles (from Olausen and Kaspi, 2014 , and references therein) . If a counterpart candidate is identified, its position is indicated by a red circle. Only the latest (2025 epoch) F160W images are shown, with

实验结果

研究问题

• RQ1 样本中的磁星近红外对应对象有哪些？
• RQ2 这些近红外磁星对应对象的自行和横向速度是多少？
• RQ3 磁星出生地是否与已知的 SNR 或星团对齐，及其推断年龄？
• RQ4 磁星横向速度分布是否与其他年轻中子星不同？
• RQ5 运动学结果对磁星形成途径（化石磁场 vs 动力学发）与形成后演化有何启示？

主要发现

• 为 PSRJ1622−4950、1RXS J170849−400910 与 CXOU J164710.2−455216 识别出新的红外对应候选对象。
• 与 1RXS J170849−400910 相关联的源的过去轨迹与 SNR G346.6−0.2 相吻合。
• 磁星的横向速度分布在统计上与年轻脉冲星不完全一致，主要原因是高速度磁星数量较少。
• 几乎在每个个案的可能过去轨迹圆锥内都识别出一个候选出生地。
• 磁星的运动学和出生地模式与更广泛的银河中子星群体大致相似，支持共同的高质量恒星核心坍缩起源。
• 有初步证据表明高速度磁星较少，这可能反映前体星差异或形成后速度演化。

Figure 2: For the cases where a good candidate was identified in the 3 $\sigma$ error circle based on distinct kinematics, colour and/or variability, and four epochs were available. Counterparts are labelled with diamonds/triangles/pentagons, other objects in the X-ray localisation regions are label