http://arxiv.org/abs/1702.05107
We conduct a systematic search for galaxies at $z=0.1-1.5$ with [OII]$\lambda3727$, [OIII]$\lambda5007$, or H$\alpha$ $\lambda6563$ emission lines extended over at least 30 kpc by using deep narrowband and broadband imaging in Subaru-XMM Deep Survey (SXDS) field. These extended emission-line galaxies are dubbed [OII], [OIII], or H$\alpha$ blobs. Based on a new selection method that securely select extended emission-line galaxies, we find 77 blobs at $z=0.40-1.46$ with the isophotal area of emission lines down to $1.2\times10^{-18}$ erg s$^{-1}$ cm$^{-2}$ kpc$^{-2}$. Four of them are spectroscopically confirmed to be [OIII] blobs at $z=0.83$. We identify AGN activities in 8 blobs with X-ray and radio data, and find that the fraction of AGN contribution increases with increasing isophotal area of the extended emission. With the Kolmogorov-Smirnov (KS) test, we confirm that the stellar-mass distributions of blobs are not drawn from those of the normal emitters at the $>95$% confidence level, but cannot reject null hypothesis of being the same distributions in terms of the specific star formation rates. Exploiting our sample homogeneously selected over the large area, we derive the number densities of blobs at each epoch. The number densities of blobs decrease drastically with redshifts at the rate that is larger than that of the decrease of cosmic star formation densities.
S. Yuma, M. Ouchi, A. Drake, et. al.
Mon, 20 Feb 17
32/37
Comments: 16 pages, 16 figures, Submitted to ApJ
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