论文标题

烛台遇到GSWLC:自z = 2以来形态与恒星形成之间关系的演变

CANDELS Meets GSWLC: Evolution of the Relationship Between Morphology and Star Formation Since z = 2

论文作者

Osborne, Chandler, Salim, Samir, Damjanov, Ivana, Faber, S. M., Huertas-Company, Marc, Koo, David C., Mantha, Kameswara Bharadwaj, McIntosh, Daniel H., Primack, Joel R., Tacchella, Sandro

论文摘要

星系形态及其对宇宙时代的演变具有理解恒星形成(SF)调节的重要线索。但是,研究形态与SF之间的关系受到不同红移的一致数据的可用性的阻碍。我们的样品结合了烛台(0.8 <z <2.5)和Galex-SDSS-Wise Legacy Catalog(GSWLC; Z〜0),具有使用一致的SED拟合及其柔性灰尘衰减定律得出的物理参数。我们采用Kartaltepe等人的视觉分类。 2015年,使用SDSS图像将其扩展到Z〜0,与烛台的物理分辨率匹配REST-FRAME光学图像和Deep Fuv Galex图像,与烛台的物理分辨率匹配REST-FRAME FUV图像。我们的主要发现是,在Z〜0处具有SF团块的磁盘将星形的星系的比例(约15%)与Z〜2时相似。集块磁盘对SF预算峰值的质量磁盘在Z〜1而不是Z〜2,这表明磁盘组件的主要时期均继续降低送货。恒星形成的球体(“蓝块”)虽然比淬灭球体的集中浓缩较少,但在Z〜1-2时对SF预算的贡献显着(〜15%),这表明压实在淬火之前。在绿色谷和静态星系中,纯球体分数从Z〜1起下降,而带有磁盘(S0类)的球体占主导地位。相对于所有红移的主要序列,SFR的合并或接近结合的合并增强了约2倍,但贡献了$ \ lyssim $ 5%的SF预算,其贡献保持在主要序列以上。

Galaxy morphology and its evolution over the cosmic epoch hold important clues for understanding the regulation of star formation (SF). However, studying the relationship between morphology and SF has been hindered by the availability of consistent data at different redshifts. Our sample, combining CANDELS (0.8 < z < 2.5) and the GALEX-SDSS-WISE Legacy Catalog (GSWLC; z ~ 0), has physical parameters derived using consistent SED fitting with flexible dust attenuation laws. We adopt visual classifications from Kartaltepe et al. 2015 and expand them to z ~ 0 using SDSS images matching the physical resolution of CANDELS rest-frame optical images and deep FUV GALEX images matching the physical resolution of the CANDELS rest-frame FUV images. Our main finding is that disks with SF clumps at z ~ 0 make a similar fraction (~15%) of star-forming galaxies as at z ~ 2. The clumpy disk contribution to the SF budget peaks at z ~ 1, rather than z ~ 2, suggesting that the principal epoch of disk assembly continues to lower redshifts. Star-forming spheroids ("blue nuggets"), though less centrally concentrated than quenched spheroids, contribute significantly (~15%) to the SF budget at z ~ 1-2, suggesting that compaction precedes quenching. Among green valley and quiescent galaxies, the pure spheroid fraction drops since z ~ 1, whereas spheroids with disks (S0-like) become dominant. Mergers at or nearing coalescence are enhanced in SFR relative to the main sequence at all redshifts by a factor of ~2, but contribute $\lesssim$5% to the SF budget, with their contribution remaining small above the main sequence.

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