星际2175A消光驼峰  

Interstellar 2175 A extinction bump

作　　者：王倩 杨雪娟 李爱根[2] WANG Qian;YANG XueJuan;LI AiGen(School of Physics and Optoelectronics,Xaingtan University,Xiangtan 411105,China;Department of Physics and Astronomy,University of Missouri,Columbia 652ll,USA)

机构地区：[1]湘潭大学物理与光电工程学院,湘潭411105 [2]美国密苏里大学物理和天文学系,美国哥伦比亚65211

出　　处：《中国科学：物理学、力学、天文学》2023年第1期137-151,共15页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:12122302,U2031114);中国载人航天工程巡天空间望远镜专项科学研究经费(编号:CMS-CSST-2021-A09)资助项目。

摘　　要：星际消光曲线包含星际尘埃化学组分和尺寸分布的重要信息.2175A消光驼峰是星际消光曲线上最为显著的光谱特征.自1965年首次观测发现以来,人们注意到,2175A消光驼峰的强度随天体环境而变化,但其峰值波长基本恒定,变化小于0.5%.我们基于国际紫外卫星(International Ultraviolet Explorer,IUE)的观测光谱以及Kurucz恒星大气模型光谱,得到了26条星际视线的紫外消光曲线.我们发现,这些星际视线的2175A消光驼峰的中心波长并不恒定在2175A附近,而是在2130–2300A范围内呈现显著变化,这与半个多世纪以来人们对2175?消光特征的通常认识不同.2175A消光驼峰的中心波长并不恒定这一新的观测特性,对驼峰载体的证认提出了新的限制.The interstellar extinction curve contains important information about the chemical composition and size distribution of interstellar dust.The 2175 A extinction bump is the most prominent spectral feature on the interstellar extinction curve.Ever since its first detection in 1965,it is well recognized that although the strength of the 2175 A extinction bump varies with astrophysical environments,its peak wavelength is invariant and is independent of environmental conditions.We derived the UV extinction curves for 26 interstellar lines of sight based on data from the International Ultraviolet Explorer(IUE)and the Kurucz stellar model atmospheric spectra.It is found that the central wavelength of the 2175 Aextinction bump of these interstellar lines of sight is not invariant around 2175 A.Instead,it exhibits considerable variation in the 2130–2300 A wavelength range,in stark contrast to the over-half-a-century-long,common belief of a stable peak wavelength of 2175 A for the extinction bump.The new observational property that the central wavelength of the 2175 A extinction bump is not constant imposes a new constraint on identifying the bump carrier.

关 键 词：2175A消光驼峰 星际消光曲线 多环芳香烃 星际尘埃 

分 类 号：P155.2[天文地球—天文学]