TY - JOUR
T1 - The Typical Massive Quiescent Galaxy at z ∼ 3 is a Post-starburst
AU - D'Eugenio, C.
AU - Daddi, E.
AU - Gobat, R.
AU - Strazzullo, V.
AU - Lustig, P.
AU - Delvecchio, I.
AU - Jin, S.
AU - Puglisi, A.
AU - Calabró, A.
AU - Mancini, C.
AU - Dickinson, M.
AU - Cimatti, A.
AU - Onodera, M.
N1 - Publisher Copyright:
© 2020. The American Astronomical Society. All rights reserved..
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/3/20
Y1 - 2020/3/20
N2 - 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 ∼ 0.6 mag) and a strong Balmer break, larger than the 4000 break, corresponding to a fairly young age of ∼300 Myr. This formally classifies a substantial fraction of classically selected quiescent galaxies at z ∼ 3 as post-starbursts, marking their convergence to the quenching epoch. The rapid spectral evolution with respect to z ∼ 1.5 quiescent galaxies is not matched by an increase of residual star formation, as judged from the weak detection of [O ii]λ3727 emission, pointing to a flattening of the steep increase in gas fractions previously seen from z ∼ 0 to 1.8. However, radio 3 GHz stacked emission implies either much stronger dust-obscured star formation or substantial further evolution in radio-mode AGN activity with respect to z ∼ 1.5.
AB - 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 ∼ 0.6 mag) and a strong Balmer break, larger than the 4000 break, corresponding to a fairly young age of ∼300 Myr. This formally classifies a substantial fraction of classically selected quiescent galaxies at z ∼ 3 as post-starbursts, marking their convergence to the quenching epoch. The rapid spectral evolution with respect to z ∼ 1.5 quiescent galaxies is not matched by an increase of residual star formation, as judged from the weak detection of [O ii]λ3727 emission, pointing to a flattening of the steep increase in gas fractions previously seen from z ∼ 0 to 1.8. However, radio 3 GHz stacked emission implies either much stronger dust-obscured star formation or substantial further evolution in radio-mode AGN activity with respect to z ∼ 1.5.
UR - http://www.scopus.com/inward/record.url?scp=85084464779&partnerID=8YFLogxK
U2 - 10.3847/2041-8213/ab7a96
DO - 10.3847/2041-8213/ab7a96
M3 - Article
AN - SCOPUS:85084464779
SN - 2041-8205
VL - 892
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1
M1 - L2
ER -