标题： 一颗在近日点附近的NH$_2$丰富的星际彗星 2I/Borisov 的画像 显示英文标题

标题： A portrait throughout perihelion of the NH$_2$-rich interstellar comet 2I/Borisov

摘要： 星际彗星2I/Borisov是第一个在其整个近日点通过过程中能够进行成分表征的星际物体。 我们报告了使用ESO VLT的积分场光谱仪MUSE进行的全面光学观测活动的所有16个时相，时间跨度为126天，从2019年11月14日到2020年3月19日。 2I/Borisov的空间尘埃发射主要平滑，没有季节性影响。 一个类似喷流的特征一直可见。 其彗发的气体生成形态也是平滑的，对于C$_2$，NH$_2$和CN来说，围绕光中心对称。 这些物质的生成率在近日点前后逐渐下降，直到2I在2020年3月初爆发和分裂事件。 C$_2$，NH$_2$和 CN的生成率都增加了，其中NH$_2$增加最为显著；尘埃发射也略微变红。 与太阳系中迄今测量的彗星相比，2I/Borisov是一个碳贫乏、相对NH$_2$含量丰富的彗星。 显示英文摘要

摘要： The interstellar comet 2I/Borisov is the first interstellar object where compositional characterisation was possible throughout its entire perihelion passage. We report all 16 epochs of a comprehensive optical observation campaign with ESO VLT's integral field spectrograph MUSE, spanning 126 days from 2019 November 14 to 2020 March 19. The spatial dust emission of 2I/Borisov was predominantly smooth, with no seasonal effect. A jet-like feature was consistently visible. The gas production morphology of its coma was also smooth and similar for C$_2$, NH$_2$, and CN: symmetric around the photocentre. The production rates of these species gently declined into and beyond perihelion, until 2I's outburst and splitting event in early 2020 March. C$_2$, NH$_2$, and CN production rates all increased, with NH$_2$ being the most significant; the dust emission also slightly reddened. 2I/Borisov is a carbon-depleted, relatively NH$_2$-rich comet when compared to those comets yet measured in the Solar System.