Quiescent Galaxies 1.5 Billion Years after the Big Bang and Their Progenitors
Quiescent Galaxies 1.5 Billion Years after the Big Bang and Their Progenitors
We report two secure ($z=3.775, 4.012$) and one tentative ($z\approx3.767$) spectroscopic confirmations of massive and quiescent galaxies through $K$-band observations with Keck/MOSFIRE and VLT/X-Shooter. The stellar continuum emission, the absence of strong nebular emission lines and the lack of significant far-infrared detections confirm the passive nature of these objects, disfavoring …