arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1104.4718astro-ph.GA
收藏

暗能量巡天:解析恒星星族的前景

The Dark Energy Survey: Prospects for Resolved Stellar Populations

B. M. Rossetto, B. X. Santiago, L. Girardi, J. I. B. Camargo, E. Balbinot, L. N. da Costa, B. Yanny, M. A. G. Maia, M. Makler, R. L. C. Ogando, P. S. Pellegrini… 展开作者

B. M. Rossetto, B. X. Santiago, L. Girardi, J. I. B. Camargo, E. Balbinot, L. N. da Costa, B. Yanny, M. A. G. Maia, M. Makler, R. L. C. Ogando, P. S. Pellegrini, B. Ramos, F. de Simoni, R. Armstrong, E. Bertin, S. Desai, N. Kuropatkin, H. Lin, J. J. Mohr, D. L. Tucker

摘要:

广角和深度巡天,无论其主要目的如何,总是对银河系及其卫星系统中的大量恒星进行采样。我们在这里作出预测的预期恒星样本产生的暗能量调查和角度,它将打开研究银河系结构和解决恒星星族一般。估计将在DES grizY滤波器中采样1.2x10^8颗恒星。这大约相当于所有DES来源的20%。这些恒星大多属于银河系的恒星厚盘和晕。DES将探测比SDSS大3至8倍的深度的低质量恒星和亚恒星物体。主序列的暗端将被密集采样超过10千秒差距。恒星IMF低质量端的斜率将被限制在百分之几的范围内,即使在厚的盘和晕中也是如此。在亚恒星质量区域,IMF斜率将潜在地被限制在dlog m(m)/ dlog m ~ 0.1$内。大约3x10^4颗褐矮星和至少7.6x10^5颗白矮星候选者将被选中,后者嵌入厚盘和晕中。恒星晕的扁平化也将被限制在百分之几以内。DES将探测新的银河系卫星和晕簇的主要序列,距离约为120 kpc,因此产生的恒星表面密度对比比SDSS大1.6-1.7倍。它还将允许在恒星晕的远处探测这些物体,大大增加探测银河系潜力的数量和质量。结合北方的样本,如SDSS,DES恒星样本将产生前所未有的详细限制银河系成分的结构和恒星星族。特别是,从两个半球的合并样本将允许详细研究晕和厚盘的不对称性和三轴性。

英文摘要:

Wide angle and deep surveys, regardless of their primary purpose, always sample a large number of stars in the Galaxy and in its satellite system. We here make a forecast of the expected stellar sample resulting from the Dark Energy Survey and the perspectives that it will open for studies of Galactic structure and resolved stellar populations in general. An estimated 1.2x10^8 stars will be sampled in DES grizY filters. This roughly corresponds to 20% of all DES sources. Most of these stars belong to the stellar thick disk and halo of the Galaxy. DES will probe low-mass stellar and sub-stellar objects at depths from 3 to 8 times larger than SDSS. The faint end of the main-sequence will be densely sampled beyond 10 kpc. The slope of the low mass end of the stellar IMF will be constrained to within a few hundredth dex, even in the thick disk and halo. In the sub-stellar mass regime, the IMF slope will be potentially constrained to within dlog ϕ(m) / dlog m ~ 0.1$. About 3x10^4 brown dwarf and at least 7.6x10^5 white dwarf candidates will be selected, the latter embedded into the thick disk and halo. The stellar halo flattening will also be constrained to within a few percent. DES will probe the main sequence of new Milky Way satellites and halo clusters for distances out to ~ 120 kpc, therefore yielding stellar surface density contrasts 1.6-1.7 times larger than those attainable with SDSS. It will also allow detection of these objects in the far reaches of the stellar halo, substantially increasing the number and quality of probes to the Galactic potential. Combined with northern samples, such as the SDSS, the DES stellar sample will yield constraints on the structure and stellar populations of Galactic components in unprecedented detail. In particular, the combined sample from both hemispheres will allow detailed studies of halo and thick disk asymmetries and triaxiality.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑