论文标题
深入寻找过氧化氢朝向前和原始物体 - 测试谷物地表水的途径
Deep search for hydrogen peroxide toward pre- and protostellar objects -- Testing the pathway of grain surface water formation
论文作者
论文摘要
背景:在实验室中,证明过氧化氢(HOOH)是固态反应方案中的中间产品,导致在冰灰尘上形成水。当Hooh从冰冷的晶粒中解脱时,可以在气相中检测到它。结合水检测,它可以提供有关水反应网络的其他信息。先前已经发现了$ρ$ OPH A的过氧化氢A。但是,其他来源中该分子的进一步搜索失败。过氧化氢在了解幼体恒星物体(YSO)中对固态水的理解和整体水库中起着基本作用。没有进一步的HOOH检测,很难评估和开发合适的化学模型,这些化学模型正确考虑了冰冷表面上的水的形成。目的:这项工作的目的是识别YSO中的HOOH,从而限制谷物地表水的形成假设。方法:使用基于先前工作的天体化学模型与YSO的物理模型结合使用,来源r cra-irs \,5a,ngcc1333-iras \,2a,2a,l1551-irs \,5,5和L1544被鉴定为可用于HOOH检测的合适候选者。在这些来源中搜索Hooh签名的最高点12M和IRAM 30M望远镜上的长时间集成时间。结果:所研究的四个来源中没有一个表现出令人信服的HOOH光谱特征。基于该分子的频率位置的噪声水平的HOOH丰度的上限对于源r cra-irs \,5a的上限接近预测值。对于NGC1333-IRA 2A,L1544和L1551-IRS \,5,该模型高估了过氧化氢的丰度。
Context: In the laboratory, hydrogen peroxide (HOOH) was proven to be an intermediate product in the solid-state reaction scheme that leads to the formation of water on icy dust grains. When HOOH desorbs from the icy grains, it can be detected in the gas phase. In combination with water detections, it may provide additional information on the water reaction network. Hydrogen peroxide has previously been found toward $ρ$ Oph A. However, further searches for this molecule in other sources failed. Hydrogen peroxide plays a fundamental role in the understanding of solid-state water formation and the overall water reservoir in young stellar objects (YSOs). Without further HOOH detections, it is difficult to assess and develop suitable chemical models that properly take into account the formation of water on icy surfaces. Aims: The objective of this work is to identify HOOH in YSOs and thereby constrain the grain surface water formation hypothesis. Methods: Using an astrochemical model based on previous work in combination with a physical model of YSOs, the sources R CrA-IRS\,5A, NGCC1333-IRAS\,2A, L1551-IRS\,5, and L1544 were identified as suitable candidates for an HOOH detection. Long integration times on the APEX 12m and IRAM 30m telescopes were applied to search for HOOH signatures in these sources. Results: None of the four sources under investigation showed convincing spectral signatures of HOOH. The upper limit for HOOH abundance based on the noise level at the frequency positions of this molecule for the source R CrA-IRS\,5A was close to the predicted value. For NGC1333-IRAS 2A, L1544, and L1551-IRS\,5, the model overestimated the hydrogen peroxide abundances.