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arXiv 1703.04801astro-ph.GA
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从{ \it Herschel}和{ \it Subaru}观测高红移星暴星系的亮面和暗面

The Bright and Dark Sides of High-Redshift starburst galaxies from {\it Herschel} and {\it Subaru} observations

A. Puglisi, E. Daddi, A. Renzini, G. Rodighiero, J. D. Silverman, D. Kashino, L. Rodríguez-Muñoz, C. Mancini, V. Mainieri, A. Man, A. Franceschini, F. Valentino… 展开作者

A. Puglisi, E. Daddi, A. Renzini, G. Rodighiero, J. D. Silverman, D. Kashino, L. Rodríguez-Muñoz, C. Mancini, V. Mainieri, A. Man, A. Franceschini, F. Valentino, A. Calabrò, S. Jin, B. Darvish, C. Maier, J. S. Kartaltepe, D. B. Sanders

摘要:

我们目前的休息帧光学光谱从FMOS-COSMOS调查的12个$z \sim 1.6$ \textit{Herschel}星暴星系,与恒星形成率(SFR)平均提高了$\times$ 8,以上的恒星形成的主序星(MS)。比较H $α$与IR的光度比和巴尔末减量,我们发现源的光学薄区域平均只包含总SFR的$\sim 10$ %,而$\sim90$ %来自一个非常模糊的成分,它只被远红外观测揭示,即使在H $α$中也是光学厚的。我们测量的[NII] $_{6583}$ /H $α$比,这表明在相同的恒星质量和红移,较不模糊的地区有类似的MS人口的金属含量。然而,我们的对象似乎是金属丰富的离群值从金属性SFR的关系,在固定的恒星质量MS人口。平均光谱的[SII] $_{6732}$ /[SII] $_{6717}$比率表明电子密度$n_{\rm e} \sim 1,100\ \mathrm{cm}^{-3}$大于MS星系的估计值,但仅在1.5 $σ$水平。我们的研究结果提供了支持的证据,高$z$ MS离群值是类似的本地ULIRGs,并与一个主要的合并起源的星爆事件是一致的。

英文摘要:

We present rest-frame optical spectra from the FMOS-COSMOS survey of twelve $z \sim 1.6$ \textit{Herschel} starburst galaxies, with Star Formation Rate (SFR) elevated by $\times$8, on average, above the star-forming Main Sequence (MS). Comparing the H$α$ to IR luminosity ratio and the Balmer Decrement we find that the optically-thin regions of the sources contain on average only $\sim 10$ percent of the total SFR whereas $\sim90$ percent comes from an extremely obscured component which is revealed only by far-IR observations and is optically-thick even in H$α$. We measure the [NII]$_{6583}$/H$α$ ratio, suggesting that the less obscured regions have a metal content similar to that of the MS population at the same stellar masses and redshifts. However, our objects appear to be metal-rich outliers from the metallicity-SFR anticorrelation observed at fixed stellar mass for the MS population. The [SII]$_{6732}$/[SII]$_{6717}$ ratio from the average spectrum indicates an electron density $n_{\rm e} \sim 1,100\ \mathrm{cm}^{-3}$, larger than what estimated for MS galaxies but only at the 1.5$σ$ level. Our results provide supporting evidence that high-$z$ MS outliers are the analogous of local ULIRGs, and are consistent with a major merger origin for the starburst event.

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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