The Typical Massive Quiescent Galaxy at z\sim3 is a Post-starburst

We have obtained spectroscopic confirmation with Hubble Space Telescope WFC3/G141 of a first sizeable sample of nine quiescent galaxies at 2.4<z<3.3. Their average near-UV/optical rest-frame spectrum is characterized by low attenuation (Av\sim0.6 mag) and a strong Balmer break, larger than the 4000 A break, corresponding to a fairly young age... Show more