ZANELLA, ANITAANITAZANELLA0000-0001-8600-7008Scarlata, C.C.ScarlataCorsini, E. M.E. M.CorsiniBedregal, A. G.A. G.BedregalDalla Bontà, E.E.Dalla BontàAtek, H.H.AtekBunker, A. J.A. J.Bunker. Colbert, J.J.. ColbertDai, Y. S.Y. S.DaiHenry, A.A.HenryMalkan, M.M.MalkanMartin, C.C.MartinRafelski, M.M.RafelskiRutkowski, M. J.M. J.RutkowskiSiana, B.B.SianaTeplitz, H.H.Teplitz2020-05-072020-05-0720160004-637Xhttp://hdl.handle.net/20.500.12386/24593We analyze how passive galaxies at z ∼ 1.5 populate the mass-size plane as a function of their stellar age, to understand if the observed size growth with time can be explained with the appearance of larger quenched galaxies at lower redshift. We use a sample of 32 passive galaxies extracted from the Wide Field Camera 3 Infrared Spectroscopic Parallel (WISP) survey with spectroscopic redshift 1.3 ≲ z ≲ 2.05, specific star formation rates lower than 0.01 Gyr<SUP>-1</SUP>, and stellar masses above 4.5 × 10<SUP>10</SUP> M <SUB>☉</SUB>. All galaxies have spectrally determined stellar ages from fitting of their rest-frame optical spectra and photometry with stellar population models. When dividing our sample into young (age ≤2.1 Gyr) and old (age >2.1 Gyr) galaxies we do not find a significant trend in the distributions of the difference between the observed radius and that predicted by the mass-size relation. This result indicates that the relation between the galaxy age and its distance from the mass-size relation, if it exists, is rather shallow, with a slope α ≳ -0.6. At face value, this finding suggests that multiple dry and/or wet minor mergers, rather than the appearance of newly quenched galaxies, are mainly responsible for the observed time evolution of the mass-size relation in passive galaxies. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.STAMPAenArticle10.3847/0004-637X/824/2/682-s2.0-84978194339000381912800004https://iopscience.iop.org/article/10.3847/0004-637X/824/2/682016ApJ...824...68ZFIS/05 - ASTRONOMIA E ASTROFISICA