A Deep Lyα Survey in ECDF-S and COSMOS. I. General Properties of Lyα Emitters at z ∼ 2

• Published in: The Astrophysical journal Vol. 864; no. 2; p. 145
• Main Authors: Hao, Cai-Na, Huang, Jia-Sheng, Xia, Xiaoyang, Zheng, Xianzhong, Jiang, Chunyan, Li, Cheng
• Format: Journal Article
• Language: English
• Published: Philadelphia IOP Publishing 10.09.2018
• Subjects: Astrophysics; Cluster analysis; Clustering; Dark matter; Emitters; Galactic halos; Galaxies; Halos; Low mass stars; Luminosity; Magellanic clouds; Narrowband; Polls & surveys; Properties (attributes); Space telescopes; Spectral energy distribution; Star & galaxy formation; Star formation; Star formation rate; Stars; Stellar mass; Ultraviolet emission
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/aad80b

Ly α emitters (LAEs) may represent an important galaxy population in the low-mass regime. We present our deep narrowband imaging surveys in the COSMOS and ECDF-S fields and study the properties of LAEs at z  = 2.23 ± 0.03. The narrowband surveys conducted at the Magellan II telescope allow us to obtain a sample of 452 LAEs, reaching a 5 σ limiting magnitude of ∼26 mag. Our Ly α luminosity functions extend to L(Ly α ) =10 41.8 erg s −1 with a steep faint-end slope. Using multiwavelength ancillary data, especially the deep Spitzer /IRAC 3.6 and 4.5 μ m photometric data, we obtained reliable stellar mass estimates for 130 IRAC-detected LAEs, spanning a range of 8 < log( M ⋆ / M ⊙ ) < 11.5. For the remaining IRAC-undetected LAEs, the median-stacked spectral energy distribution yields a stellar mass of and the rest-frame ultraviolet emission indicates a median star formation rate (SFR) of log (SFR/ M ⊙ yr −1 ) = −0.14 ± 0.35. There are six LAEs detected by the Spitzer /MIPS 24 μ m or even Herschel far-infrared observations. Taking into account the six mid-IR/far-IR-detected LAEs, our LAEs cover a wide range in the SFR (1 M ⊙ yr −1  < SFR < 2000 M ⊙ yr −1 ). Although LAEs as a population are diverse in their stellar properties, they are mostly low-mass star-forming galaxies and follow the star formation main-sequence relations or their extrapolations to the low-mass end, implying a normal star-forming nature of LAEs. The clustering analysis indicates that our LAEs reside in dark matter halos with , suggesting that they are progenitors of local LMC-like galaxies.