Abstract
Abstract
We present results of [C ii] 158 μm emission line observations, and report the spectroscopic redshift confirmation of a strongly lensed (μ ∼ 20) star-forming galaxy, MACS0308-zD1 at z = 6.2078 ± 0.0002. The [C ii] emission line is detected with a signal-to-noise ratio >6 within the rest-frame UV-bright clump of the lensed galaxy (zD1.1) and exhibits multiple velocity components; the narrow [C ii] has a velocity full width half maximum (FWHM) of 110 ± 20 km s−1, while broader [C ii] is seen with an FWHM of 230 ± 50 km s−1. The broader [C ii] component is blueshifted (−80 ± 20 km s−1) with respect to the narrow [C ii] component, and has a morphology that extends beyond the UV-bright clump. We find that, while the narrow [C ii] emission is most likely associated with zD1.1, the broader component is possibly associated with a physically distinct gas component from zD1.1 (e.g., outflowing or inflowing gas). Based on the nondetection of λ
158μm dust continuum, we find that MACS0308-zD1's star formation activity occurs in a dust-free environment indicated by a strong upper limit of infrared luminosity ≲9 × 108
L
⊙. Targeting this strongly lensed faint galaxy for follow-up Atacama Large Millimeter/submillimeter Array and JWST observations will be crucial to characterize the details of typical galaxy growth in the early Universe.
Funder
National Astronomical Observatory of Japan
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
Swedish National Space Agency
Javna Agencija za Raziskovalno Dejavnost RS
United States-Israel Binational Science Foundation
National Science Foundation
Agencia Nacional de Investigación y Desarrollo
ANID ∣ Fondo Nacional de Desarrollo Científico y Tecnológico
MEXT ∣ Japan Society for the Promotion of Science
Publisher
American Astronomical Society
Subject
Space and Planetary Science,Astronomy and Astrophysics