We present the results of near-infrared spectroscopy using Keck/MOSFIRE for 23 member galaxies in the X-ray cluster XCS 2215 (z = 1.46) to investigate the environmental dependence of gaseous flows and metallicities. We find that the metallicities derived from Hα and [N II] emission lines of the cluster galaxies are enhanced by 0.08─0.15 dex with

The Milky Way serves as a template for understanding the formation and evolution of late-type massive disk galaxies since we can obtain detailed chemical and kinematic information for large samples of individual stars. However, the early formation of the disk and the dichotomy between the chemically thick and thin disks remain under intense debate

Scattering polarization signals offer unique diagnostics of the physical conditions in the solar atmosphere, in particular magnetic fields via the Hanle effect. However, their spatial structure remains poorly constrained due to the difficulty of achieving a high spatial resolution and polarimetric sensitivity simultaneously. We present the first

Aims. Determining the dynamical mass profiles of dispersion-supported galaxies is particularly challenging due to projection effects and the unknown shape of their velocity anisotropy profile. Traditionally, this task relies on time-consuming methods that require profile parameterisation and the assumption of dynamical equilibrium and spherical

We report the discovery of a new directly imaged brown-dwarf companion with Keck/NIRC2+pyWFS around a nearby mid-type M-dwarf LSPM J1446+4633 (hereafter J1446). The L ' -band contrast (4.5 × 10 ‑3) is consistent with a ∼20–60 M Jup object at 1–10 Gyr and our two-epoch NIRC2 data suggest a ∼30% (∼3.1σ) variability in its L ' -band flux. We