A high redshift population of galaxies at the North Ecliptic Pole
A high redshift population of galaxies at the North Ecliptic Pole
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DOI：
10.1051/0004-6361/202037838
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发表时间：
2020-07
影响因子：
6.5
通讯作者：
L. Barrufet;C. Pearson;S. Serjeant;K. Małek;I. Baronchelli;M. C. Campos-Varillas;G. White;I. Valtchanov;H. Matsuhara;L. Conversi;S. Kim;T. Goto;N. Oi;M. Malkan;Helen K. Kim;H. Ikeda;T. Takagi;Y. Toba;T. Miyaji
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文献类型：
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作者：
L. Barrufet;C. Pearson;S. Serjeant;K. Małek;I. Baronchelli;M. C. Campos-Varillas;G. White;I. Valtchanov;H. Matsuhara;L. Conversi;S. Kim;T. Goto;N. Oi;M. Malkan;Helen K. Kim;H. Ikeda;T. Takagi;Y. Toba;T. Miyaji
上下文尘埃高z星系是具有高星星形成率（SFR）和光度的极端天体。描述这个群体的特性并分析它们在宇宙时间内的演化是理解早期宇宙中星系演化的关键。目标。我们选择了一个样本的高Z尘埃恒星形成星系（DSFG）和评估其位置的主要序列（MS）的恒星形成星系，恒星质量和SFR之间的众所周知的相关性。我们的目标是了解他们的高星星形成的原因，并量化的百分比DSFG以上的MS。我们采用了多波长的方法，从光学到亚毫米波长的数据，从调查在北极研究一个亚毫米样本的高红移星系。使用了两种亚毫米选择方法，包括：用亚毫米普通用户测辐射热计阵列2）SCUBA-2仪器在850微米处选择源，用赫歇尔光谱和光度成像接收器选择源（彩色图和500微米彩色图），发现185个源具有良好的多波长覆盖。所得的185个高z候选者的样品通过用CIGALE拟合代码进行光谱能量分布拟合来进一步研究。我们推导出光度红移，恒星质量，SFR，和额外的物理参数，如红外光度和活动星系核（AGN）的贡献。结果我们发现，Herschel-SPIRE选择的DSFG通常具有更高的红移（z = 2.57−0.09+0.08）比单独使用SCUBA-2方法选择的源（z = 1.45−0.06+0.21）。我们发现中等SFR（797−50+108 M yr−1），通常低于其他研究中发现的值。我们发现，文献中的不同结果，只是部分，由于选择效应，即使在最极端的情况下，SFR仍然低于几千太阳质量每年。在测量的SFR的差异影响的位置的DSFG的MS的星系;大多数的DSFG谎言的MS（60%）。最后，我们发现星系中星星形成效率（SFE）依赖于星系中星星形成爆发的时代和强度，爆发越晚，星星形成越强烈。我们讨论是否较高的SFE在DSFG可能是由于合并。
Context. Dusty high-z galaxies are extreme objects with high star formation rates (SFRs) and luminosities. Characterising the properties of this population and analysing their evolution over cosmic time is key to understanding galaxy evolution in the early Universe. Aims. We select a sample of high-z dusty star-forming galaxies (DSFGs) and evaluate their position on the main sequence (MS) of star-forming galaxies, the well-known correlation between stellar mass and SFR. We aim to understand the causes of their high star formation and quantify the percentage of DSFGs that lie above the MS. Methods. We adopted a multi-wavelength approach with data from optical to submillimetre wavelengths from surveys at the North Ecliptic Pole to study a submillimetre sample of high-redshift galaxies. Two submillimetre selection methods were used, including: sources selected at 850 μm with the Sub-millimetre Common-User Bolometer Array 2) SCUBA-2 instrument and Herschel-Spectral and Photometric Imaging Receiver (SPIRE) selected sources (colour-colour diagrams and 500 μm risers), finding that 185 have good multi-wavelength coverage. The resulting sample of 185 high-z candidates was further studied by spectral energy distribution fitting with the CIGALE fitting code. We derived photometric redshifts, stellar masses, SFRs, and additional physical parameters, such as the infrared luminosity and active galactic nuclei (AGN) contribution. Results. We find that the Herschel-SPIRE selected DSFGs generally have higher redshifts (z = 2.57−0.09+0.08) than sources that are selected solely by the SCUBA-2 method (z = 1.45−0.06+0.21). We find moderate SFRs (797−50+108 M⊙ yr−1), which are typically lower than those found in other studies. We find that the different results in the literature are, only in part, due to selection effects, as even in the most extreme cases, SFRs are still lower than a few thousand solar masses per year. The difference in measured SFRs affects the position of DSFGs on the MS of galaxies; most of the DSFGs lie on the MS (60%). Finally, we find that the star formation efficiency (SFE) depends on the epoch and intensity of the star formation burst in the galaxy; the later the burst, the more intense the star formation. We discuss whether the higher SFEs in DSFGs could be due to mergers.