arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1604.01698astro-ph.GA
收藏

COSMOS场中的星暴星系:红移0 < z < 0.5时的星团恒星形成

Starburst galaxies in the COSMOS field: clumpy star-formation at redshift 0 < z < 0.5

R. Hinojosa-Goñi, C. Muñoz-Tuñón, J. Méndez-Abreu

摘要:

在高红移,星暴星系呈现不规则的形态,10- 20%的恒星形成发生在巨大的团块中。这些星团星系被认为是本地盘星系的祖先。要了解中低红移的恒星爆的性质,必须追踪它们的演化以及与高$z$系统的可能联系。利用哈勃空间望远镜/高级巡天照相机(HST/ACS)图像,对COSMOS领域中的星暴星系($0 < z < 0.5$)进行了广泛、系统、多波段的搜索和分析,并详细研究了它们的成星团特征。它们的主要性质、大小、质量和恒星形成率都被提供。在我们的样本中,单个的恒星形成结遵循与局部巨HII区相同的L(H $α$)与大小的比例关系(Fuentes-Masip et al. 2000)。然而,它们与使用高红移样品提供的结果略有不同。这一结果突出了空间分辨恒星形成区域对这种研究的重要性。Mknot星系中心区域的恒星形成团块比外围区域的质量更大,恒星形成率也更高。当我们考虑质量表面密度或表面恒星形成率时,这种趋势就模糊了。Sknot星系在表面亮度($μ$)与$B-$带中的M $_{host}$图(Amorín et al. 2012)中确实显示出类似于矮椭圆星系和不规则星系的性质,在$μ$与$V-$带中的M $_{host}$图(Kormendy \&\ Bender 2012)中也显示出类似于椭球星系和椭圆星系的性质。Sknot星系可能是BCD类的过渡阶段,其性质与类球形,但蓝色结构一致。

英文摘要:

At high redshift, starburst galaxies present irregular morphologies, with 10-20\%\ of their star formation occurring in giant clumps. These clumpy galaxies are considered to be the progenitors of local disk galaxies. To understand the properties of starbursts at intermediate and low redshift, it is fundamental to track their evolution and possible link with the systems at higher $z$. We present an extensive, systematic, and multi-band search and analysis of the starburst galaxies at redshift ($0 < z < 0.5$) in the COSMOS field, as well as detailed characteristics of their star-forming clumps by using Hubble Space Telescope/Advance Camera for Surveys (HST/ACS) images. Their principal properties, sizes, masses, and star formation rates are provided. The individual star-forming knots in our sample follow the same L(H$α$) vs. size scaling relation than local giant HII regions (Fuentes-Masip et al. 2000). However, they slightly differ from the one provided using samples at high redshift. This result highlights the importance of spatially resolving the star-forming regions for this kind of study. Star-forming clumps in the central regions of Mknots galaxies are more massive, and present higher star formation rates, than those in the outskirts. This trend is smeared when we consider either the mass surface density or surface star formation rate. Sknot galaxies do show properties similar to both dwarf elliptical and irregulars in the surface brightness ($μ$) versus M$_{host}$ diagram in the $B-$band (Amorín et al. 2012), and to spheroidals and ellipticals in the $μ$ versus M$_{host}$ diagram in the $V-$band (Kormendy \&\ Bender 2012). Sknot galaxies might be transitional phases of the BCD class, with their properties consistent with spheroidal like, but blue structures.

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。

↑