Accretion Disks Around Young Massive Stars

年轻大质量恒星周围的吸积盘

• 批准号: 0098524
• 负责人: Peter Hofner
• 金额: $ 18.8万
• 依托单位: University of Puerto Rico-Rio Piedras
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-01 至 2004-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0098524&HistoricalAwards=false
• 关键词: Accretion; Disks; Around; Young; Massive

" Accretion Disks Around Young Massive Stars"AST- 0098524Massive stars are responsible for many of the basic characteristics of spiral galaxies. They effectively dictate the properties of the interstellar medium through their strong ionizing radiation, vigorous outflowing winds and eventual demise as supernovae explosions. They also influence the formation of subsequent generations of stars by triggering the initial collapse of cloud cores of molecular dust and gas. The dominant mechanism by which high mass stars form remains one of the outstanding problems of stellar astrophysics. Most likely, the mechanism is similar to that which produces low mass stars through the formation and collapse of protostellar disks. But, in the case of massive stars, there must be important modifications to the star forming process brought on by the enormous radiation pressure from the massive protostars. The possibility exists that there is an alternative route for producing stars in the high-mass range but first it is important to look hard for the signatures of disks. Through this award the PI will turn to radio astronomy and exploit the capabilities of the Very Large Array (VLA) and the Very Large Baseline Array to search for and subsequently study disks of this type. The VLA will be used to directly image the dust continuum emission from the accretion disk at a wavelength of 7 mm. The VLBA will be used to identify accretion disks in another way, via the strong water maser line at a wavelength of 1.3 cm and to use this as a kinetic probe. Whether the accretion disks are detected or not, the proposed observations will provide high angular resolution observations of matter in the vicinity of young massive stars.

“年轻大质量恒星周围的吸积盘”AST-0098524 大质量恒星造成了螺旋星系的许多基本特征。它们通过强烈的电离辐射、剧烈的外流风以及最终作为超新星爆炸而消亡，有效地决定了星际介质的特性。它们还通过引发分子尘埃和气体云核的初始塌陷来影响后代恒星的形成。高质量恒星形成的主导机制仍然是恒星天体物理学的突出问题之一。最有可能的是，该机制类似于通过原恒星盘的形成和坍缩产生低质量恒星的机制。但是，就大质量恒星而言，来自大质量原恒星的巨大辐射压力必然会对恒星形成过程产生重要的改变。存在一种可能性，即存在一种替代途径来产生高质量范围内的恒星，但首先重要的是要努力寻找圆盘的特征。通过该奖项，PI 将转向射电天文学，并利用甚大阵列 (VLA) 和甚大基线阵列的功能来搜索并随后研究此类磁盘。 VLA 将用于直接对吸积盘发出的波长为 7 毫米的尘埃连续谱发射进行成像。 VLBA 将用于以另一种方式识别吸积盘，即通过波长为 1.3 厘米的强水脉瑟线，并将其用作动力学探针。无论是否检测到吸积盘，所提出的观测都将为年轻大质量恒星附近的物质提供高角分辨率观测。