The Role of Quenching Time in the Evolution of the Mass-size Relation of Passive Galaxies from the WISP Survey

Authors

A. Zanella, University of Minnesota
C. Scarlata, University of MinnesotaFollow
E. Corsini, University of Padua
A. Bedregal, Tufts University
E. Bontà, University of Padua
H. Atek, California Institute of TechnologyFollow
A. Bunker, University of OxfordFollow
J Colbert, Harvard UniversityFollow
Y. Dai, Infrared Processing and Analysis Center, 770 South Wilson Avenue, Pasadena, CA 91125, USAFollow
A. Henry, Goddard Space Flight CenterFollow
M. Malkan, University of California, Los AngelesFollow
C. Martin, University of California, Santa BarbaraFollow
M. Rafelski, Goddard Space Flight CenterFollow
Michael J. Rutkowski, Minnesota State University, Mankato
B. Siana, University of California, RiversideFollow
H. Teplitz, California Institute of TechnologyFollow

Document Type

Article

Publication Date

6-14-2016

Abstract

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−1, and stellar masses above 4.5 × 1010M⊙. 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.

Department

Physics and Astronomy

Print ISSN

0004-637X

Online ISSN

1538-4357

Publication Title

The Astrophysical Journal

Recommended Citation

Zanella, A., Scarlata, C., Corsini, E. M., Bedregal, A. G., Dalla Bonta, E., Atek, H., Bunker, A. J., Colbert, J., Dai, Y. S., Henry, A., Malkan, M., Martin, C., Rafelski, M., Rutkowski, M. J., Siana, B., Teplitz, H. (2016). The role of quenching time in the evolution of the mass-size relation of passive galaxies from the WISP survey. The Astrophysical Journal, 824(2), Article 68. https://doi.org/10.3847/0004-637X/824/2/68

DOI

10.3847/0004-637X/824/2/68

Link to Publisher Version (DOI)

https://doi.org/10.3847/0004-637X/824/2/68

Publisher's Copyright and Source

Copyright © 2016. The American Astronomical Society. All rights reserved.