Energetic photon irradiation of carbonaceous icy grains–laboratory studies on the interstellar ice-dust interface in star-forming regions

碳质冰粒的高能光子辐照——恒星形成区星际冰尘界面的实验室研究

• 批准号: 468269691
• 负责人: Dr. Cornelia Jäger
• 金额: --
• 依托单位: Sterrewacht Leiden
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/468269691?language=en
• 关键词: Energetic; photon; irradiation; carbonaceous; icy

In the dense interstellar medium, cosmic dust grains are covered by a molecular ice layer. These grains consisting of a refractory and a volatile component are expected to be continuously irradiated by energetic photons. Thin molecular ice layers of about 10 nm on dust grains can be penetrated by photons. They can interact with the refractory dust material activating photon-induced reactions in the ice/dust material and at the ice-dust interface. The proposed project between the Laboratory Astrophysics and Cluster Physics Group in Jena and the Photoprocessing Spectroscopy Laboratory in Taiwan is dedicated to the investigation of photon-induced modifications of ice-dust grains in the interstellar medium and in star-forming regions. The interface between ice and dust is characterized by a large contact area due to the small sizes of particles and the high porosity of the dust agglomerates. The joint research project under the DFG-MOST program is established to study the ice-dust interface processing triggered by energetic photons comprising vacuum ultraviolet photons (E <10.9 eV), extreme ultraviolet photons (E=11-40 eV), and soft X-ray photons (E= 80-1200 eV). This research will address three different objectives namely the possible interactions of radicals with carbonaceous dust surfaces leading to the erosion of the material, the formation of organic and prebiotic molecules at the ice-dust interface and the effect of energetic photons on the composition and structure of the refractory dust materials. We will include amorphous and hydrogenated amorphous carbon nanoparticles with fullerene-like structural subunits and silicate/carbon mixtures. Systematic experimental studies as a function of typical interstellar parameters such as temperature and photon energy will be performed on dust analogs covered by pure ices including H2O, NH3, CH4, H2S, N2 and O2. The outcome of this project on energetic grain/ice processing will improve our knowledge on the interstellar grain evolution and will help to better understand the ingredients of planetary systems and planets. It will also be important for Astrochemistry, Astrobiology, and (Exo-)Planetary Science. The research project is an innovative and timely preparation of the upcoming James Webb Space Telescope expected to be launched in 2021, which will reveal the details of interstellar ice and dust in exceptionally high IR spectral resolution and sensitivity.

在密集的星际介质中，宇宙尘埃颗粒被分子冰层覆盖。这些由耐火材料和挥发性成分组成的颗粒预计将受到高能光子的持续照射。尘埃颗粒上约10 nm的分子冰层可以被光子穿透。它们可以与难熔的尘埃材料相互作用，在冰/尘埃材料和冰尘界面上激活光子引发的反应。设在耶拿的实验室天体物理和星团物理小组与台湾的光处理光谱实验室之间的拟议项目致力于研究星际介质和恒星形成区域中冰尘颗粒的光子诱导修改。冰尘界面的特点是接触面积大，这是由于颗粒尺寸小，粉尘团聚的高孔隙率所致。DFG-MOST计划下的联合研究项目是为了研究由高能光子触发的冰尘界面过程，高能光子包括真空紫外线光子(E&lt；10.9 eV)、极端紫外线光子(E=11-40 eV)和软X射线光子(E=80-1200 eV)。这项研究将涉及三个不同的目标，即自由基与碳质粉尘表面可能导致材料侵蚀的相互作用，在冰尘界面形成有机分子和益生菌分子，以及高能光子对耐火粉尘材料的组成和结构的影响。我们将包括具有富勒烯结构亚单位的非晶态和氢化非晶态碳纳米颗粒以及硅酸盐/碳混合物。系统的实验研究将作为典型星际参数的函数，如温度和光子能量，将在包括H2O、NH3、CH4、硫化氢、氮气和氧气在内的纯冰覆盖的尘埃类似物上进行。这一高能谷物/冰加工项目的成果将提高我们对星际谷物演化的认识，并将有助于更好地了解行星系统和行星的成分。它对天体化学、天体生物学和(外)行星科学也将是重要的。该研究项目是对即将到来的詹姆斯·韦伯太空望远镜的创新和及时准备，预计将于2021年发射，该望远镜将以异常高的红外光谱分辨率和灵敏度揭示星际冰和尘埃的细节。