THE ROLE OF QUENCHING TIME IN THE EVOLUTION OF THE MASS–SIZE RELATION OF PASSIVE GALAXIES FROM THE WISP SURVEY
- Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis MN 55455 (United States)
- Dipartimento di Fisica e Astronomia “G. Galilei,” Università di Padova, vicolo dell’Osservatorio 3, I-35122 Padova (Italy)
- Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States)
- Spitzer Science Center, Caltech, Pasadena, CA 91125 (United States)
- Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX13RH (United Kingdom)
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
- Infrared Processing and Analysis Center, 770 South Wilson Avenue, Pasadena, CA 91125 (United States)
- Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States)
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095 (United States)
- Department of Physics, University of California, Santa Barbara, CA, 93106 (United States)
- Department of Physics and Astronomy, University of California Riverside, Riverside, CA 92521 (United States)
We 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}, and stellar masses above 4.5 × 10{sup 10} M {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.
- OSTI ID:
- 22666186
- Journal Information:
- Astrophysical Journal, Vol. 824, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Early-type galaxies at intermediate redshift observed with Hubble space telescope WFC3: perspectives on recent star formation
The ages, metallicities, and element abundance ratios of massive quenched galaxies at z≃1.6