Astronomy Picture of the Day——雪茄星系的中央磁场
The Central Magnetic Field of the CigarGalaxy
Image Credit: NASA, SOFIA, E.Lopez-Rodriguez; NASA, Spitzer, J. Moustakas et al.
Explanation: Are galaxies giant magnets?Yes, but the magnetic fields in galaxies are typically much weaker than onEarth\'s surface, as well as more complex and harder to measure. Recently,though, the HAWC+ instrument onboard the airborne (747) SOFIA observatory hasbeen successful in detailing distant magnetic fields by observing the polarizedinfrared light emitted by elongated dust grains rotating in alignment with thelocal magnetic field. HAWC+ observations of M82, the Cigar galaxy, show thatthe central magnetic field is perpendicular to the disk and parallel to thestrong supergalactic wind. This observation bolsters the hypothesis that M82\'scentral magnetic field helps its wind transport the mass of millions of starsout from the central star-burst region. The featured image shows magnetic fieldlines superposed on top of an optical light (gray) and hydrogen gas (red) imagefrom Kitt Peak National Observatory, further combined with infrared images(yellow) from SOFIA and the Spitzer Space Telescope. The Cigar Galaxy is about12 million light years distant and visible with binoculars towards theconstellation of the Great Bear.
雪茄星系的中央磁场
星系是巨大的磁体吗？回答是肯定的，但是星系的磁场通常比地球表面的弱得多，而且更复杂，更难测量。然而，最近，机载（747）索菲亚平流层红外天文台上的HAWC+仪器通过观察尘埃颗粒反射的偏振红外光，成功描述了遥远的磁场。在上面的这幅特征图像中，HAWC+对雪茄星系M82的观测表明，中央磁场垂直于星系盘，并与强烈的超星系风平行。这个观测结果支撑了一则假设，M82的中央磁场有助于它的星系风将数百万恒星的质量从中心恒星爆发区传送出去。这幅特征图像呈现了叠加在基特峰国家天文台拍摄的一幅可见光（灰色）和氢气（红色）影像之上的磁场线，并进一步与索菲亚平流层红外天文台和斯皮策望远镜拍摄的红外影像（黄色）相结合。雪茄星系距离地球约1200万光年，用双筒望远镜朝向大熊座方向可以发现它。
参考文献：
https://apod.nasa.gov/apod/image/1903/M82Magnet_SOFIA_2412.jpg
近期文章：
Astronomy Picture of the Day——朱诺号拍摄到形似大理石的木星