Systematic Survey for [O ii], [O iii], and Hα Blobs at z = 0.1–1.5: The Implication for Evolution of Galactic-scale Outflow

Journal Article · Thu Jun 01 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA709F· OSTI ID:22872667

Yuma, Suraphong ^[1]; Ouchi, Masami; Fujimoto, Seiji; Kojima, Takashi; Sugahara, Yuma ^[2]

---

1. Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400 (Thailand)
2. Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa-no-ha, Kashiwa 277-8582 (Japan)

We conduct a systematic search for galaxies at z=0.1--1.5 with [O ii]λ3727, [O iii]λ5007, or Hα λ6563 emission lines extended over at least 30 kpc by using deep narrowband and broadband imaging in the Subaru-XMM Deep Survey field. These extended emission-line galaxies are dubbed [O ii], [O iii], or Hα blobs. Based on a new selection method that securely selects extended emission-line galaxies, we find 77 blobs at z=0.40--1.46 with the isophotal area of emission lines down to 1.2×10{sup −18} erg s{sup −1} cm{sup −2} kpc{sup −2}. Four of them are spectroscopically confirmed to be [O iii] blobs at z = 0.83. We identify AGN activities in eight 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) and Anderson–Darling tests, we confirm that the stellar-mass distributions of Hα and [O ii] blobs are not drawn from those of the emitters at the >90% confidence level in that Hα and [O ii] blobs are located at the massive end of the distributions, but cannot reject a null hypothesis of being the same distributions in terms of the specific star formation rates. It is suggested that galactic-scale outflows tend to be more prominent in more massive star-forming galaxies. 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 a rate that is larger than that of the decrease of cosmic star formation densities.

• OSTI ID: 22872667
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 841; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
EMISSION
GALACTIC EVOLUTION
GALAXIES
MASS DISTRIBUTION
OXYGEN
RED SHIFT
STARS
WAVELENGTHS