Infrared imaging and polarimetric observations of the pulsar wind nebula in SNR G21.5-0.9
A. Zajczyk, Y. A. Gallant, P. Slane, S. P. Reynolds, R. Bandiera, C. Gouiffès, E. Le Floc'h, F. Comerón, L. Koch Miramond
备注：
11 pages, 13 figures, accepted by A&A; more detailed discussion of the reduction and analysis of the narrow-band imaging data added in Sect. 2.4, which results in the change of the structure of Fig.4; uncertainty of the infrared power-law index re-estimated, results in updating Fig.6; minor changes in Sect. 4.2 to estimates of X-ray fluxes and their uncertainties and also to the radio upper limit
We present infrared observations of the supernova remnant G21.5-0.9 with the Very Large Telescope, the Canada-France-Hawaii Telescope and the Spitzer Space Telescope. Using the VLT/ISAAC camera equipped with a narrow-band [FeII] 1.64um filter the entire pulsar wind nebula in SNR G21.5-0.9 was imaged. This led to detection of iron line-emitting material in the shape of a broken ring-like structure following the nebula's edge. The detected emission is limb-brightened. We also detect the compact nebula surrounding PSR J1833-1034, both through imaging with the CFHT/AOB-KIR instrument (K' band) and the IRAC camera (all bands) and also through polarimetric observations performed with VLT/ISAAC (Ks band). The emission from the compact nebula is highly polarised with an average value of the linear polarisation fraction $P_{L}^{avg} \simeq 0.47$, and the swing of the electric vector across the nebula can be observed. The infrared spectrum of the compact nebula can be described as a power law of index $α_{IR} = 0.7 \pm 0.3$, and suggests that the spectrum flattens between the infrared and X-ray bands.
Detailed Interstellar Polarimetric Properties of the Pipe Nebula at Core Scales
我们使用R波段CCD线性偏振仪收集了约12000背景场恒星在46个领域的看法对烟斗星云的整个黑暗的云的偏振特性进行调查。根据2MASS的存档数据，我们估计调查区域的总视觉反射率在0.6 < Av < 4.6的范围内。虽然观察到的偏振显示出一个有序的大尺度模式，偏振矢量几乎垂直对准云的长轴，在核心尺度上，人们看到的细节是每个核心的特征。虽然许多观测到的恒星呈现出对普通星际介质来说不寻常的偏振度，但我们的分析表明，构成烟斗星云弥漫部分的尘埃颗粒似乎与正常的银河系星际介质具有相同的性质。偏振角的二阶结构函数的估计表明，大部分的烟斗星云是磁占主导地位，湍流是次Alvenic。烟斗星云当然是一个有趣的区域，在那里可以研究低质量恒星形成的初始阶段的主要过程。
NAS RA V.Ambartsumian Byurakan Astrophysical Observatory (BAO)（亚美尼亚国家科学院瓦·安巴尔楚勉比尤拉坎天体物理观测台）；The Silk Road Project at the National Astronomical Observatory, Chinese Academy of Sciences（中国科学院国家天文台丝绸之路项目）
Exploring the central region of SNR 0540-69.3 with JWST I: 3D morphology
KTH Royal Institute of Technology（皇家理工学院）；Stellenbosch Institute for Advanced Study (STIAS)（斯坦伦布什高等研究院）；Stellenbosch University（斯坦伦布什大学）；Stockholm University（斯德哥尔摩大学）；European Southern Observatory（欧洲南方天文台）
