天文学进展
天文學進展
천문학진전
PROGRESS IN ASTRONOMY
2014年
4期
462-480
,共19页
白矮-主序双星%双星演化%后共包层双星
白矮-主序雙星%雙星縯化%後共包層雙星
백왜-주서쌍성%쌍성연화%후공포층쌍성
white dwarf-main sequence binary%binary evolution%post-common-envelope binaries
白矮–主序双星是银河系中最常见的致密双星系统，它包含一颗白矮星主星和一颗小质量主序星伴星，由主序双星演化而来。大约1/4的白矮–主序双星经历过一个公共包层演化阶段，其轨道间距较小，周期很短，被称为后共包层双星；而另外3/4的白矮–主序双星则从未经历过公共包层演化，其轨道间距几乎与其最初的主序双星的相同，被称为宽距白矮–主序双星。在光学波段，一般从白矮–主序双星的光谱上能明显地看出其有两个成分。随着大型巡天项目如SDSS、LAMOST巡天的开展，近年来搜寻到的白矮–主序双星的数目越来越多。通过对搜寻到的白矮–主序双星进行大量的后续观测，已从中发现并确认了一大批后共包层双星。利用观测到的白矮–主序双星及后共包层双星样本，有助于我们进一步理解密近双星的演化过程，尤其是公共包层演化的物理机制等重要的天体物理热点议题。介绍了白矮–主序双星的形成和演化，回顾了大型巡天项目中白矮–主序双星的系统搜寻，以及基于这些白矮–主序双星样本获得的研究成果，最后对白矮–主序双星的搜寻研究做了展望。
白矮–主序雙星是銀河繫中最常見的緻密雙星繫統，它包含一顆白矮星主星和一顆小質量主序星伴星，由主序雙星縯化而來。大約1/4的白矮–主序雙星經歷過一箇公共包層縯化階段，其軌道間距較小，週期很短，被稱為後共包層雙星；而另外3/4的白矮–主序雙星則從未經歷過公共包層縯化，其軌道間距幾乎與其最初的主序雙星的相同，被稱為寬距白矮–主序雙星。在光學波段，一般從白矮–主序雙星的光譜上能明顯地看齣其有兩箇成分。隨著大型巡天項目如SDSS、LAMOST巡天的開展，近年來搜尋到的白矮–主序雙星的數目越來越多。通過對搜尋到的白矮–主序雙星進行大量的後續觀測，已從中髮現併確認瞭一大批後共包層雙星。利用觀測到的白矮–主序雙星及後共包層雙星樣本，有助于我們進一步理解密近雙星的縯化過程，尤其是公共包層縯化的物理機製等重要的天體物理熱點議題。介紹瞭白矮–主序雙星的形成和縯化，迴顧瞭大型巡天項目中白矮–主序雙星的繫統搜尋，以及基于這些白矮–主序雙星樣本穫得的研究成果，最後對白矮–主序雙星的搜尋研究做瞭展望。
백왜–주서쌍성시은하계중최상견적치밀쌍성계통，타포함일과백왜성주성화일과소질량주서성반성，유주서쌍성연화이래。대약1/4적백왜–주서쌍성경력과일개공공포층연화계단，기궤도간거교소，주기흔단，피칭위후공포층쌍성；이령외3/4적백왜–주서쌍성칙종미경력과공공포층연화，기궤도간거궤호여기최초적주서쌍성적상동，피칭위관거백왜–주서쌍성。재광학파단，일반종백왜–주서쌍성적광보상능명현지간출기유량개성분。수착대형순천항목여SDSS、LAMOST순천적개전，근년래수심도적백왜–주서쌍성적수목월래월다。통과대수심도적백왜–주서쌍성진행대량적후속관측，이종중발현병학인료일대비후공포층쌍성。이용관측도적백왜–주서쌍성급후공포층쌍성양본，유조우아문진일보리해밀근쌍성적연화과정，우기시공공포층연화적물리궤제등중요적천체물리열점의제。개소료백왜–주서쌍성적형성화연화，회고료대형순천항목중백왜–주서쌍성적계통수심，이급기우저사백왜–주서쌍성양본획득적연구성과，최후대백왜–주서쌍성적수심연구주료전망。
White dwarf-main sequence binaries (WDMS) are the most common compact binary ob jects in the Galaxy, each of which consists of a white dwarf and a main sequence star and is evolved from main sequence binary. About 25 percent of the WDMS binaries are close WDMS binaries that evolved through a common envelope phase, and are commonly referred to as post-common-envelope binaries (PCEBs). The remaining 75 percent are wide WDMS binaries that did not evolve through a common envelope phase, with the orbital separation roughly the same as the orbital separation of the initial main sequence binary. Generally, the two components can be seen clearly from the WDMS binary spectra optically. <br> Thanks to the large spectroscopic survey like SDSS and LAMOST, the number of WDMS binaries has been increased dramatically recently. A large number of wide WDMS binaries and PCEBs have been identified by the follow-up observations of these WDMS bina-ries. Currently, more than 2000 WDMS binaries have been discovered spectroscopically and about 200 PCEBs have been confirmed. Upon the large sample of SDSS WDMS binaries and PCEBs identified, many important researches have been carried on, such as the com-mon envelope theory, the origin of low mass white dwarf, mass-radius relations of both white dwarfs and low mass main sequence stars, and the pairing properties of main sequence stars. However, as the SDSS WDMS binaries sample has serious selection effects, which is strongly biased against binary systems containing cool white dwarf and/or early type companions, we still need to search more WDMS binaries to enlarge the sample. The LAMOST sky survey began its five years regular survey from September 2012, which will observe a large number of targets in the Milky Way. From the recent data release (DR1) of LAMOST, more than 100 WDMS binaries have been found. With the ongoing SDSS and LAMOST survey, more WDMS binaries are hoped to be identified and extend the existing WDMS binary sample. <br> In this paper, we give a detailed review on WDMS binaries including the formation and evolution of WDMS PCEBs, the identification of WDMS binaries, and the recent research progresses and future prospects.
