Fundamental Characteristics of Very Low Mass Objects

奖项编号：AST-0606748 PI：Gilbor Basri机构：加州伯克利大学标题：极低质量天体的基本特征摘要本研究的中心是收集观测数据和发展分析工具，以进一步了解极低质量恒星、棕矮星、和巨大的太阳系外行星（统称为极低质量物体）的基本参数的确定问题（质量、半径、温度、表面重力、成分、旋转和磁场）和大气过程（尘埃形成、磁加热和光谱形成）以及它们的形成、频率和双星性。将采用的主要工具是高分辨率光谱学，它将通过“精细分析技术”得到单个极低质量物体的基本参数。这些将依次应用于一个广泛的领域对象和对象在星星形成地区。此外，这些导出的参数将用于校准和改进非常低质量物体的演化模型，既可以理解它们的早期演化，也可以将演化模型的使用置于理解非常低质量的星星形成的更好基础上。观测双星中的低质量物体将被用来更好地了解极低质量天体的双星频率和分离分布，作为测试其形成模式模型的一种手段，并有助于了解在新的参数制度中多物体形成过程本身。此外，将继续对低质量物体的旋转和活动进行研究，进行实际的磁场测量，并对不同类型的物体进行更广泛的取样。最后，作为校准M星和早期L星基本参数工作的一部分，将开始研究组成对极低质量天体大气化学和光谱形成的影响，这一项目将支持一名新研究生的论文工作，并有助于培养在这一小组工作的下一代科学家。巴斯里博士定期通过会谈和媒体参与公共外联活动，他在这些领域的活动将继续下去。

AWARD NO: AST-0606748PI: Gilbor BasriINSTITUTION: University of California BerkeleyTITLE: Fundamental Characteristics of Very Low Mass ObjectsABSTRACTThis research centers on the collection of observations and the development of analysistools to further our understanding of the characteristics of very low mass stars, browndwarfs, and giant extrasolar planets (collectively referred to as very low mass objects).The work is intended to address issues with the determination of the fundamentalparameters very low mass objects (mass, radius, temperature, surface gravity,composition, rotation, and magnetic fields) and atmospheric processes (dust formation,magnetic heating, and spectral formation) as well as their formation, frequency and thebinarity. The principle tool to be employed is high resolution spectroscopy which herewill be developed and calibrated through "fine analysis techniques" for obtainingfundamental parameters of single very low mass objects. These will in turn be applied toa broad set of both field objects and objects in star forming regions. Moreover, thesederived parameters will be used to calibrate and improve evolutionary models of verylow mass objects, both to understand their early evolution and to place the use ofevolutionary models in understanding star formation on a better footing for very lowmasses. Observations of low mass objects in binaries will be used to gain a betterunderstanding of the binary frequency and separation distribution of very low massobjects as a means of testing models of their formation modes and to help inunderstanding the process of multi-object formation itself in a new parameter regime. Inaddition, studies of studies of rotation and activity in low mass objects will be continuedby pursuing actual magnetic field measurements as well as a broader sample of differenttypes of objects. Finally, the study of the effects of composition on the atmosphericchemistry and spectral formation in very low mass objects will be begun as part of theeffort to calibrate the fundamental parameters of M and early L stars.This project will support the thesis work of a new graduate student as well as contributeto the training of the next generation of scientists in working in this group. Dr. Basriregularly engages in public outreach through talks and through the media and hisactivities in these areas will continue.