학술논문

ALMA [C II] 158 μm Detection of a Redshift 7 Lensed Galaxy behind RX J1347.1-1145
Document Type
article
Source
Astrophysical Journal Letters. 836(1)
Subject
dark ages
reionization
first stars
galaxies: clusters: individual
galaxies: high-redshift
gravitational lensing: strong
astro-ph.GA
astro-ph.CO
dark ages
reionization
first stars
Astronomy & Astrophysics
Astronomical and Space Sciences
Language
Abstract
We present the results of ALMA spectroscopic follow-up of a z =6.766 Lyα emitting galaxy behind the cluster RX J1347.1-1145. We report the detection of [C ii] 158 μm line fully consistent with the Lyα redshift and with the peak of the optical emission. Given the magnification of μ =5.0 ±0.3, the intrinsic (corrected for lensing) luminosity of the [C ii] line is L [C ii] = 1.4+0.2-0.3 × 107 L⊙, roughly ∼5 times fainter than other detections of z ∼ 7 galaxies. The result indicates that low L [C ii] in z ∼ 7 galaxies compared to the local counterparts might be caused by their low metallicities and/or feedback. The small velocity offset (δv = 20+140-40 Km s-1) between the Lyα and [C ii] line is unusual, and may be indicative of ionizing photons escaping.