Clustering of the AKARI NEP deep field 24 μm selected galaxies
Clustering of the AKARI NEP deep field 24 μm selected galaxies
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AKARI NEP 深场 24 μm 选定星系的聚类
DOI：
10.1051/0004-6361/201423370
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发表时间：
2015
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影响因子：
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通讯作者：
M.
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文献类型：
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作者：
Solarz;A.; Pollo;A.; Takeuchi;T. T.; Malek;K.; Matsuhara;H.; White;G.;J.; Pepiak;A.; Goto;T.; Wada;T.; Oyabu;S.; Takagi;T.; Ohyama;Y.; Pearson;C. P.; Hanami;H.; Ishigaki;T.; Malkan;M.
目的提出一种从AKARI北黄道极（NEP）深场至150μJy范围内选取24μm星系的方法，并测量它们的两点相关函数。我们的目标是将不同的24μm星系群与现今的星系相关联，并研究它们的环境对它们随后演化方向的影响。MethodsWe讨论了使用支持向量机（SVM）算法应用于红外光度数据进行星-星系分离，其中我们达到了80%以上的精度。通过CIGALE码获得的光度红移信息，被用来探索红移相关函数参数（r 0）的依赖以及线性偏压的演变。该参数将星系分布与底层暗物质的分布联系起来。我们通过一个简化的模型的集群演化没有interactions.ResultsWe观察到两个不同的人口的恒星形成星系，atzmed~ 0.25，zmed ~ 0.9，我们调查的来源，他们潜在的本地后代。红外总光度（LTIR）的测量结果表明，atzmed~ 0.25的样品主要由本星系组成，atzmed~ 0.9的样品主要由LTIR ~ 1011.62L的亮红外星系组成。我们发现暗晕质量与LTIR并不必然相关：对于LTIR = 1011.15L λ atzmed~ 0.7的子样本，我们观察到比平均LTIR = 1011.84L λ atzmed~ 1.1的子样本（r 0 = 5.86 ± 0.69h-1 Mpc）更高的聚类长度（r 0 = 6.21 ± 0.78[h-1 Mpc]）。我们发现zmed ~ 0.9的星系可能是现今L型星系的祖先，它们具有很高的r 0 ~ 8h-1 Mpc。
AimsWe present a method of selection of 24μm galaxies from the AKARI north ecliptic pole (NEP) deep field down to 150μJy and measurements of their two-point correlation function. We aim to associate various 24μm selected galaxy populations with present day galaxies and to investigate the impact of their environment on the direction of their subsequent evolution.MethodsWe discuss using of Support Vector Machines (SVM) algorithm applied to infrared photometric data to perform star-galaxy separation, in which we achieve an accuracy higher than 80%. The photometric redshift information, obtained through the CIGALE code, is used to explore the redshift dependence of the correlation function parameter (r0) as well as the linear bias evolution. This parameter relates galaxy distribution to the one of the underlying dark matter. We connect the investigated sources to their potential local descendants through a simplified model of the clustering evolution without interactions.ResultsWe observe two different populations of star-forming galaxies, atzmed~ 0.25,zmed~ 0.9. Measurements of total infrared luminosities (LTIR) show that the sample atzmed~ 0.25 is composed mostly of local star-forming galaxies, while the sample atzmed~ 0.9 is composed of luminous infrared galaxies (LIRGs) withLTIR~ 1011.62L⊙. We find that dark halo mass is not necessarily correlated with theLTIR: for subsamples withLTIR= 1011.15L⊙atzmed~ 0.7 we observe a higher clustering length (r0= 6.21 ± 0.78[h-1Mpc ]) than for a subsample with meanLTIR= 1011.84L⊙atzmed~ 1.1 (r0= 5.86 ± 0.69h-1Mpc). We find that galaxies atzmed~ 0.9 can be ancestors of present dayL∗early type galaxies, which exhibit a very highr0~ 8h-1Mpc.