arXiv 1809.014742018-09astro-ph.SR

利用WISE全天巡天追踪北冕座R星

Tracking down R Coronae Borealis stars using the WISE All-Sky survey

P. Tisserand, G. C. Clayton, D. L. Welch

备注：: Article withdraw as its contents was merged into the following article arXiv:1809.01743 titled "A plethora of new R Coronae Borealis stars discovered from a dedicated spectroscopic follow-up survey"

摘要：

北冕座R星（RCB）是中等质量白矮星（$0.4<M_{tot}<1.1$ M $_{\odot}$）合并的最佳候选者。在合并之后，He包层围绕着CO核心，并且开始了短暂的超巨星阶段。RCB对应于该阶段。它们是贫氢富碳的超巨星。它们是罕见的;它们在化学丰度，亮度和光球温度方面也高度多样化。为了了解它们的进化路径，限制它们的空间分布并测试它们的形成率，我们的目标是显着增加已知RCB的数量。要做到这一点，我们首先需要创建一个富含RCB恒星的目标列表，随后将通过光谱进行跟踪，以揭示它们的真实性质。幸运的是，RCB正在产生尘埃，因此被温暖的拱星尘埃壳包围。利用全天2 MASS和WISE红外巡天，我们的目标是在其他产生尘埃的恒星中区分RCB。一系列的选择标准适用于颜色-颜色图和所有编目对象的亮度。该标准是使用所有102颗已知的RCB恒星设计的。RCB SED模型也被用来了解标准的限制和可能的偏差，在壳温度选择。RCB恒星已知会经历不可预测的光度下降，这使得分析变得复杂。在探测效率约为85%的情况下，我们的分析仅在WISE全天巡天中编目的5.63亿个对象中选择了2356个目标。这份简短的目标清单取代了先前发布的WISE初步数据。这份发表在CDS Vizier数据库中的名单将使我们能够显着增加已知RCB恒星的数量。

英文摘要：

R Coronae Borealis stars (RCBs) are the best candidates to be the products of white dwarf mergers in the intermediate mass range ($0.4<M_{tot}<1.1$ M$_{\odot}$). After a merger, a He envelope surrounds a CO core, and a short-lived supergiant phase starts. RCBs correspond to that phase. They are known to be hydrogen-deficient and carbon-rich supergiant stars. They are rare; They are also highly diverse in chemical abundances, brightness and photosphere temperature. To understand their evolutionary path, constrain their spatial distribution and test their formation rate, we aim to increase significantly the number of known RCBs. To do so, we need first to create a list of targets of interest rich in RCB stars, that will be subsequently followed-up spectroscopically to reveal their true nature. Fortunately, RCBs are producing dust and are therefore surrounded by warm circumstellar dust shells. Using the all-sky 2MASS and WISE infrared surveys, our goal is to discriminate RCBs among other dust-producing stars. A series of selection criteria was applied to colour-colour diagrams and to the brightness of all objects catalogued. The criteria were designed using all 102 known RCB stars. RCB SED models were also used to understand the limits of the criteria and the possible bias in terms of shell temperature selected. The analysis was complicated by the unpredictable photometric declines that RCB stars are known to undergo. With a detection efficiency of about 85\%, our analysis selected only 2356 targets among the 563 million objects catalogued in the WISE All-Sky survey. This short list of targets of interest supersedes a previously published one made from the preliminary WISE data release. This list, published in the CDS Vizier database, will allow us to increase significantly the number of known RCB stars.

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。

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英文摘要：

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