中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
THE QUENCHED MASS PORTION OF STAR-FORMING GALAXIES AND THE ORIGIN OF THE STAR FORMATION SEQUENCE SLOPE

文献类型:期刊论文

作者Pan, Zhizheng; Zheng, Xianzhong; Kong, Xu
刊名ASTROPHYSICAL JOURNAL
出版日期2017
卷号834期号:1页码:39-39
英文摘要Observationally, a massive disk galaxy can harbor a bulge component that is comparably inactive as a quiescent galaxy. It has been speculated that the quenched component contained in star-forming galaxies (SFGs) is the reason why the star formation main sequence (MS) has a shallow slope at high masses. In this paper, we present a toy model to quantify the quenched mass portion of SFGs (f(Q)) at fixed stellar mass (M-*) and to reconcile the MS slopes in both the low-and the high-mass regimes. In this model, each SFG is composed of a star-forming plus a quenched component. The mass of the star-forming component (M-SF) correlates with the star formation rate (SFR) following a relation SFR alpha M-SF(alpha SF), where alpha(SF) similar to 1.0. The quenched component contributes to the stellar mass but not to the SFR. It is thus possible to quantify f(Q) based on the departure of the observed MS slope a from aSF. Adopting the redshift-dependent MS slope reported by Whitaker et al., we explore the evolution of the f(Q) -M-* relations over z = [0.5, 2.5]. We find that Milky Way-like SFGs (with M-* approximate to 10(10.7) M-circle dot) typically have an f(Q) = 30%-40% at z similar to 2.25, whereas this value rapidly rises up to 70%-80% at z similar to 0.75. The origin of an alpha similar to 1.0 MS slope seen in the low-mass regime is also discussed. We argue for a scenario in which the majority of low-mass SFGs stay in a "steady-stage" star formation phase. In this phase, the SFR is mainly regulated by stellar feedback and not significantly influenced by the quenching mechanisms, thus remaining roughly constant over cosmic time. This scenario successfully produces an alpha similar to 1.0 MS slope, as well as the observed MS evolution from z = 2.5 to z - 0 at low masses.
语种英语
源URL[http://libir.pmo.ac.cn/handle/332002/17394]  
专题中国科学院紫金山天文台
推荐引用方式
GB/T 7714
Pan, Zhizheng,Zheng, Xianzhong,Kong, Xu. THE QUENCHED MASS PORTION OF STAR-FORMING GALAXIES AND THE ORIGIN OF THE STAR FORMATION SEQUENCE SLOPE[J]. ASTROPHYSICAL JOURNAL,2017,834(1):39-39.
APA Pan, Zhizheng,Zheng, Xianzhong,&Kong, Xu.(2017).THE QUENCHED MASS PORTION OF STAR-FORMING GALAXIES AND THE ORIGIN OF THE STAR FORMATION SEQUENCE SLOPE.ASTROPHYSICAL JOURNAL,834(1),39-39.
MLA Pan, Zhizheng,et al."THE QUENCHED MASS PORTION OF STAR-FORMING GALAXIES AND THE ORIGIN OF THE STAR FORMATION SEQUENCE SLOPE".ASTROPHYSICAL JOURNAL 834.1(2017):39-39.

入库方式: OAI收割

来源:紫金山天文台

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