标题： SPHEREx对3I/ATLAS中强水冰吸收和扩展二氧化碳彗发的发现 显示英文标题

标题： SPHEREx Discovery of Strong Water Ice Absorption and an Extended Carbon Dioxide Coma in 3I/ATLAS

摘要： 2025年8月中旬，获得了星际物体3I ATLAS的0.75-5.0微米SPHEREx成像光谱测光以及辅助的NASA-IRTF SpeX 0.7-2.5微米低分辨率光谱观测数据。 组合光谱主要由水冰吸收特征和CO2气体发射特征主导。 一个明亮的、半径为3角分的CO2气体彗发被清晰分辨，对应的Qgas,CO2 = 9.4 x 10{^26} 分子/秒。 根据SPHEREx测光，我们对H2O和CO的气体生成速率给出了保守的初步3sigma上限，分别为1.5 x 10{^26} 和2.8 x 10{^26} 分子/秒。 在SPHEREx图像中未发现明显的喷流、尾部或轨迹结构。 假设所有观测到的1微米通量都是来自albedo = 0.04的球形核的散射光，其半径将是23公里。 与Jewitt+ 2025给出的核大小限制r = 2.8公里相比，这表明测量的SPHEREx连续谱通量的99%以上来自彗发尘埃。 显示英文摘要

摘要： In mid-August 2025, 0.75-5.0 micron SPHEREx imaging spectrophotometric and ancillary NASA-IRTF SpeX 0.7-2.5 micron low-resolution spectral observations of Interstellar Object 3I ATLAS were obtained. The combined spectrophotometry is dominated by features due to water ice absorption and CO2 gas emission. A bright, 3 arcmin radius CO2 gas coma was clearly resolved, corresponding to Qgas,CO2 = 9.4 x 10{^26} molec/sec. From the SPHEREx photometry, we put conservative, preliminary 3sigma upper limits on the gas production rates for H2O and CO of 1.5 x 10{^26} and 2.8 x 10{^26} molec/sec. No obvious jet, tail, or trail structures were found in SPHEREx images. Assuming all observed 1-um flux is scattered light from an pv = 0.04 albedo spherical nucleus, its radius would be 23 km. Compared to the nucleus size limit r = 2.8km of Jewitt+ 2025, this suggests that greater than 99 percent of the measured SPHEREx continuum flux is from coma dust.