Collaborative Project: Star Formation Processes in Irregular Galaxies

合作项目：不规则星系中的恒星形成过程

• 批准号: 9802193
• 负责人: Deidre Hunter
• 金额: $ 22.33万
• 依托单位: Lowell Observatory
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-15 至 2001-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9802193&HistoricalAwards=false
• 关键词: Collaborative; Project; Star; Formation; Processes

AST-9802193 Hunter Irregular galaxies are the most common type of galaxy in the Universe. Because they have evolved relatively slowly over time, they chemically resemble the outer parts of present day spirals and young galaxies seen at large look-back times. Unlike spirals, however, irregulars have no density waves and less shear in their interstellar media. Yet, most irregulars have on-going star formation. Therefore, non-interacting irregular galaxies give us the opportunity to examine processes of star formation in the absence of spiral density waves and external perturbations. These processes may play an important role in spiral galaxies too, but there they are masked by the consequences of the density wave. Dr. Hunter is collaborating with Dr. Elmegreen to answer the question: What regulates the star formation activity in irregular galaxies on global and local scales? They are proceeding (1) to quantify the nature and distribution of the star formation activity, (2) to characterize the interstellar medium out of which clouds and stars form, and (3) to combine the observations with models to develop a realistic picture for the onset of star formation in these systems. The observations probe star formation on three timescales: H a images trace the most recent star formation, UBV images integrate the star formation over the past Gyr, and JHK images integrate the star formation over the lifetime of the galaxy. To characterize the interstellar medium, the team is using radio interferometer maps of HI line emission and absorption. ***

AST-9802193 Hunter 不规则星系是宇宙中最常见的星系类型。 因为它们随着时间的推移演化得相对缓慢，所以它们在化学上类似于现在的螺旋星系和年轻星系的外部。 然而，不规则星与螺旋星不同，它们的星际介质中没有密度波，切变也较少。然而，大多数不规则星都有持续的星星形成过程。 因此，非相互作用的不规则星系使我们有机会在没有螺旋密度波和外部扰动的情况下研究星星的形成过程。 这些过程可能在螺旋星系中也扮演重要角色，但在那里，它们被密度波的结果所掩盖。 亨特博士正在与埃尔默格林博士合作回答这个问题：是什么在全球和局部尺度上调节不规则星系中的星星形成活动？ 他们正在着手（1）量化星星形成活动的性质和分布，（2）描述形成云和恒星的星际介质的特征，以及（3）将观测与模型相结合，为这些系统中星星形成的开始绘制一幅真实的图像。 观测探测星星的形成在三个时间尺度上：H a图像跟踪最近的星星形成，UBV图像整合了过去Gyr的星星形成，JHK图像整合了星系一生中的星星形成。 为了描述星际介质的特征，研究小组正在使用HI线发射和吸收的无线电干涉仪图。 ***