摘要
碳是宇宙中仅次于氢、氦、氧的第4丰富的元素.在恒星演化晚期形成的碳元素,进入星际空间以后,以离子、原子、分子以及固体尘埃微粒的多种形式存在.含碳有机复杂分子是生命起源的基本物质.碳质尘埃是星际尘埃的主要成分之一,其红外光谱是探测各种天体环境物理和化学条件的重要指针.碳质尘埃如石墨、纳米金刚石、多环芳香烃、富勒烯、氢化非结晶碳等尘埃微粒是星际尘埃的重要研究对象,在星际空间广泛存在,它们是星际消光2175?驼峰、星际红外辐射谱带、星际弥散吸收带等光谱特征的最可能载体.本文主要介绍星际碳质尘埃的天文观测及其物理化学特性.近年来,石墨烯、碳纳米管逐渐进入人们的视野,本文亦将讨论与此相关的天文观测和理论模型的最新进展.
Carbon is the fourth most abundant element in the Universe after hydrogen, helium and oxygen. Synthesized at the late evolutionary stage of stars, carbon is ejected from stars through mass loss of asymptotic giant branch stars and explosion of supernovae and then enters the interstellar medium in the form of ions, atoms, molecules and solid dust particles. Carbon-containing complex organic molecules are essential for the origins of life, and carbonaceous dust is a major component of interstellar grains whose infrared absorption and emission spectra provide a powerful diagnosis of the physical and chemical conditions of astrophysical regions where the dust is found. Carbonaceous dust materials such as graphite, nanodiamonds, polycyclic aromatic hydrocarbon molecules, fullerene, and hydrogenated amorphous carbon are ubiquitously present in the interstellar space and are the most promising candidate carriers of the unidentified 2175 A extinction bump, the unidentified infrared emission bands at 3.3, 6.2, 7.7, 8.6, and 11.3 μm, and the mysterious diffuse interstellar absorption bands. Here we focus on the observational properties of interstellar carbonaceous grains and their physical and chemical characteristics. Also discussed are graphene and carbon nanotubes which may be present in the interstellar space.
作者
陈秀慧
李爱根
向福元
杨雪娟
钟建新
CHEN XiuHui LI AiGen XIANG FuYuan YANG XueJuan ZHONG JianXin(School of Physics and Optoelectronics Department of Phystcs and Astronomy, Xiangtan University, Xiangtan 411105, China University of Missouri, Columbia 65211, USA)
出处
《中国科学:物理学、力学、天文学》
CSCD
北大核心
2017年第8期60-73,共14页
Scientia Sinica Physica,Mechanica & Astronomica
基金
国家自然科学基金(编号:11473023
11273022
U1531108)
美国自然科学基金(编号:NSF AST-1311804)
美国国家航空航天局基金(编号NNX13AE63G)
湖南省研究生科研创新项目(编号:CX2015B213)资助
关键词
星际碳尘埃
星际消光
星际红外辐射
星际弥散带
interstellar carbonaceous dust, interstellar extinction, interstellar infrared emissions, diffuse interstellar bands