Testing Claims of Different Stellar Initial Mass Functions

他们将研究恒星是否以同样的方式在整个宇宙中形成。他们的具体问题是，在附近星系中形成的恒星是否遵循与我们星系中相同的星星出生重量分布。我们银河系中的一些恒星出生时是巨大的巨星，而另一些则是小矮星，但天文学家发现了恒星大小的模式，称为初始质量函数（IMF）。 他们设计了一个实验来确定这种模式是否具有普遍性。 他们问题的答案对于理解星系如何形成以及这些星系是否包含暗物质非常重要。基于对银河系星星形成区的广泛研究，传统观点认为IMF是不变的。然而，基于对星暴星系、椭圆星系和高红移宇宙的观测的间接证据表明存在一些变化。这两个论点都没有说服力。银河系的研究并不限制IMF在所有的环境，因为他们探测一个有限的参数范围（星际辐射场，密度）。另一方面，河外星系的论点是基于高度简化的恒星种群模型，对星星形成历史和演化恒星的光度几乎没有限制。扎里茨基之前已经发现了本星系群内IMF变化的直接证据，在那里可以详细研究恒星种群，并且比太阳附近的环境范围更广。在大多数较老的星团中，推断的IMF与太阳附近的恒星分布一致。他们将尝试使用一种观测遥远星星群的新型摄像系统来证明出生体重变化的重要性。他们的项目将培养一名研究生，并证明这种新型高灵敏度摄像系统的能力。 此外，他们还计划以他们的研究成果为基础，举办一系列公开讲座，阐述科学思想是如何发展的。

They will study whether stars form in the same manner throughout the Universe. Their specific question is whether stars form in nearby galaxies follow the same distribution of star birth weights as is found in our galaxy. Some stars in our galaxy are born as massive giants and others are small dwarfs, but astronomers have found a pattern in the sizes of stars, called the Initial Mass Function (IMF). They have devised an experiment to determine whether this pattern is universal. The answer to their question is important for understanding how galaxies form and whether these galaxies contain dark matter. Conventional wisdom, based on extensive studies of Galactic star formation regions, is that the IMF is invariant. However, indirect evidence based on observation of starburst galaxies, elliptical galaxies, and the high redshift universe suggests that some variations exist. Neither argument is convincing. Galactic studies do not constrain the IMF in all environments because they probe a limited parameter range (interstellar radiation field, density). On the other hand, the extragalactic arguments are based on highly simplified stellar population modeling, with few constraints on star formation histories and the luminosities of evolved stars.Zaritsky has previously uncovered straightforward evidence for IMF variations within the Local Group of galaxies, where it is possible to study the stellar populations in detail and over a wider range of environments than found near the Sun. In mostly older stellar clusters, the inferred IMF is consistent with distribution of stars in the local neighborhood near our Sun. They will attempt to prove the significance of the variations in birth weights using a remarkable new camera system for observing distant star clusters.Their project will train a graduate student and prove the capabilities of the new high sensitivity camera system. In addition, they plan to use their research results as the basis for a set of public lectures to illustrate how scientific thought develops.