SOFIA Far-infrared Imaging Polarimetry of M82 and NGC 253: Exploring the Supergalactic Wind
SOFIA Far-infrared Imaging Polarimetry of M82 and NGC 253: Exploring the Supergalactic Wind
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M82 和 NGC 253 的 SOFIA 远红外成像偏振测量：探索超星系风
DOI：
10.3847/2041-8213/aaf8b9
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Edward J. Wollack
中科院分区：
文献类型：
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作者：
T. Jones;C. Dowell;E. L. Rodriguez;E. Zweibel;M. Berthoud;D. Chuss;P. Goldsmith;R. Hamilton;S. Hanany;D. Harper;7. A. Lazarian;L. Looney;J. Michail;M. Morris;G. Novak;F. Santos;K. Sheth;G. Stacey;J. Staguhn;I. Stephens;K. Tassis;C. Trinh;C. Volpert;M. Werner;Edward J. Wollack
本文介绍了在平流层红外天文台上用高分辨率机载宽带相机（HAWC+）在偏振测量模式下对M82在53和154 μ m以及NGC 253在89 μ m的远红外偏振测量观测。M82在53 μ m处的偏振清楚地显示了在热尘埃发射中垂直于盘的磁场几何形状。对于M82，在154 μ m处的偏振显示了在核区域中垂直于圆盘的场几何结构的组合，但在远离核的区域中更接近于平行于圆盘。在53 μ m（154 μ m）处的部分偏振范围从离核7%（3%）到近核0.5%（0.3%）。对M82观测结果的一个简单解释是，从一个直径约为700 pc的区域中产生了一个巨大的极地外流，拖着磁场沿着运动，这个区域夹带了一些气体和尘埃，产生了一个垂直的磁场几何形状，主要见于较热的（53 μ m）尘埃发射。这种外流位于一个更大的圆盘内，具有更典型的平面几何形状，更强烈地促进了较冷（154 μ m）的尘埃排放。对于NGC 253，在89 μ m处的偏振主要由倾斜盘中的平面几何结构所控制，在核平面的上方和下方有微弱的垂直几何结构。NGC 253在53 μ m处的偏振观测的信噪比不足以进行详细的分析。
We present far-infrared polarimetry observations of M82 at 53 and 154 μm and NGC 253 at 89 μm, which were taken with High-resolution Airborne Wideband Camera-plus (HAWC+) in polarimetry mode on the Stratospheric Observatory for Infrared Astronomy. The polarization of M82 at 53 μm clearly shows a magnetic field geometry perpendicular to the disk in the hot dust emission. For M82 the polarization at 154 μm shows a combination of field geometry perpendicular to the disk in the nuclear region, but closer to parallel to the disk away from the nucleus. The fractional polarization at 53 μm (154 μm) ranges from 7% (3%) off nucleus to 0.5% (0.3%) near the nucleus. A simple interpretation of the observations of M82 invokes a massive polar outflow, dragging the field along, from a region ∼700 pc in diameter that has entrained some of the gas and dust, creating a vertical field geometry seen mostly in the hotter (53 μm) dust emission. This outflow sits within a larger disk with a more typical planar geometry that more strongly contributes to the cooler (154 μm) dust emission. For NGC 253, the polarization at 89 μm is dominated by a planar geometry in the tilted disk, with weak indication of a vertical geometry above and below the plane from the nucleus. The polarization observations of NGC 253 at 53 μm were of a insufficient signal-to-noise ratio for a detailed analysis.