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

基本信息

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

项目摘要

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猎人不规则星系是宇宙中最常见的星系类型。由于它们随着时间的流逝的发展相对较慢，因此它们在化学上类似于当今的螺旋和年轻星系的外观，在大量外观时代看到。然而，与螺旋形不同，不规则的人星际介质中没有密度波，剪切较少。然而，大多数不规则的恒星形成。因此，在没有螺旋密度波和外部扰动的情况下，非相互作用的不规则星系使我们有机会检查恒星形成的过程。这些过程也可能在螺旋星系中起重要作用，但是在那里，它们被密度波的后果所掩盖。 Hunter博士正在与Elmegreen博士合作回答以下问题：是什么调节了全球和本地尺度上不规则星系中的星形形成活动？他们正在进行（1）量化恒星形成活性的性质和分布，（2）表征星际介质的云层和恒星形成，以及（3）将观测值与模型相结合，以开发这些系统中恒星形成的现实情况。观察结果探测三个时标：H图像追踪最新的恒星形成，UBV图像在过去的回旋中整合了恒星形成，JHK图像在银河系的寿命中整合了恒星形成。为了表征星际介质，团队使用了HI线发射和吸收的无线电干涉仪图。 ***