| Journal Title /掲載ジャーナル名 |
The Astrophysical Journal Letters |
| Publication Year and Month /掲載年月 |
July, 2022 |
| Paper Title /論文タイトル |
Possible Systematic Rotation in the Mature Stellar Population of a z=9.1 Galaxy |
| DOI /論文DOI |
10.3847/2041-8213/ac7447 |
| Author of Waseda University /本学の著者 |
INOUE, Akio(Professor(without tenure), Faculty of Science and Engineering, School of Advanced Science and Engineering):Corresponding Author |
| Related Websites /関連Web |
– |
| Abstract /抄録 |
We present new observations with the Atacama Large Millimeter/submillimeter Array for a gravitationally lensed galaxy at z = 9.1, MACS1149-JD1. [O iii] 88 μm emission is detected at 10σ with a spatial resolution of ∼0.3 kpc in the source plane, enabling the most distant morphokinematic study of a galaxy. The [O iii] emission is distributed smoothly without any resolved clumps and shows a clear velocity gradient with ΔVobs/2σtot = 0.84 ± 0.23, where ΔVobs is the observed maximum velocity difference and σtot is the velocity dispersion measured in the spatially integrated line profile, suggesting a rotating system. Assuming a geometrically thin self-gravitating rotation disk model, we obtain  , where Vrot and σV are the rotation velocity and velocity dispersion, respectively, still consistent with rotation. The resulting disk mass of  M⊙ is consistent with being associated with the stellar mass identified with a 300 Myr old stellar population independently indicated by a Balmer break in the spectral energy distribution. We conclude that the most of the dynamical mass is associated with the previously identified mature stellar population that formed at z ∼ 15. |
