发表机构
University College London; Smithsonian Astrophysical Observatory（伦敦大学学院; 史密森尼天体物理台）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
利用WISE 14.5年多历元数据，发现52颗含尘白矮星碎片盘普遍存在亮度变化且红外超持续，通量长期偏向减小，支持尘埃逐渐耗损，并揭示盘光度与钙丰度正相关。
AI 中文摘要
本研究利用广域红外巡天探测器（WISE）的多历元测光数据，结合其低温与低温后阶段完整的14.5年任务数据集，调查白矮星碎片盘中的变异性。在52颗已确认的含尘白矮星中，大部分探测到了明确的亮度变化，且在针对WISE相对于斯皮策（Spitzer）的灵敏度进行校正后，这些变化与普遍存在的变异性一致。部分碎片盘的光变曲线呈现出趋势性特征，如可能的振荡、突然增亮以及持续衰减的通量，但所有红外超均完全持续存在。在超过0.5年的基线上，通量变化显著偏向于减小，这与斯皮策在较短基线上发现的对称分布形成对比，与随时间逐渐发生的尘埃耗损相一致。碎片盘辐射通常在变暗时变得更红，在变亮时变得更蓝，这与碰撞后颗粒尺寸分布的变化一致，不过有五个碎片盘表现出相反趋势，可能源于近拱点附近的尘埃产生。观测到碎片盘光度与光球层钙丰度之间存在中等程度的正相关，这与光学薄构型下盘物质的吸积相一致。结合斯皮策对含尘白矮星的长期观测遗产，这些结果提供了碎片盘变异性全景视图，并为碎片盘结构与演化模型提供了经验约束。
英文摘要
This study presents multi-epoch photometry from the Wide-field Infrared Survey Explorer to investigate variability in white dwarf debris disks, utilizing the full 14.5 yr mission datasets pre- and post-cryogen. Unambiguous variations are detected across the bulk of the 52 confirmed dusty white dwarfs and are consistent with universal variability after correcting for the sensitivity of WISE relative to Spitzer. Some disk light curves exhibit trends such as possible oscillations, sudden brightening, and steadily decaying fluxes, but all infrared excesses persist utterly. On baselines longer than 0.5 yr, flux changes are significantly skewed toward decreases, in contrast to the symmetric distribution found at shorter baselines with Spitzer, consistent with gradual dust depletion over time. Disk emission generally becomes redder when dimmer and bluer when brighter, consistent with changes in the grain size distribution following collisions, although five disks exhibit the opposite trend possibly due to dust production near apastron. A moderate positive correlation is observed between disk luminosity and photospheric Ca abundance, consistent with the accretion of disk material in an optically thin configuration. Taken together with the Spitzer legacy of dusty white dwarfs, these results provide a comprehensive view of debris disk variability and provide empirical constraints on models of disk structure and evolution.
Comments20 pages, 3 tables, 8 figures (including appendices). Submitted to MNRAS (in revision)
