# Extending the evolution of the stellar mass–size relation at <i>z</i> ≤ 2 to low stellar mass galaxies from HFF and CANDELS

Nedkova, Kalina V and Häußler, Boris and Marchesini, Danilo and Dimauro, Paola and Brammer, Gabriel and Eigenthaler, Paul and Feinstein, Adina D and Ferguson, Henry C and Huertas-Company, Marc and Johnston, Evelyn J and Kado-Fong, Erin and Kartaltepe, Jeyhan S and Labbé, Ivo and Lange-Vagle, Daniel and Martis, Nicholas S and McGrath, Elizabeth J and Muzzin, Adam and Oesch, Pascal and Ordenes-Briceño, Yasna and Puzia, Thomas and Shipley, Heath V and Simmons, Brooke D and Skelton, Rosalind E and Stefanon, Mauro and van der Wel, Arjen and Whitaker, Katherine E (2021) Extending the evolution of the stellar mass–size relation at <i>z</i> ≤ 2 to low stellar mass galaxies from HFF and CANDELS. Monthly Notices of the Royal Astronomical Society, 506 (1). pp. 928-956. ISSN 0035-8711

Text (nedkova_etal_2021)
nedkova_etal_2021.pdf - Accepted Version

## Abstract

We reliably extend the stellar mass–size relation over 0.2 ≤ z ≤ 2 to low stellar mass galaxies by combining the depth of Hubble Frontier Fields with the large volume covered by CANDELS. Galaxies are simultaneously modelled in multiple bands using the tools developed by the MegaMorph project, allowing robust size (i.e. half-light radius) estimates even for small, faint, and high redshift galaxies. We show that above 107 M⊙, star-forming galaxies are well represented by a single power law on the mass–size plane over our entire redshift range. Conversely, the stellar mass–size relation is steep for quiescent galaxies with stellar masses $\ge 10^{10.3}\, {\rm M}_\odot$ and flattens at lower masses, regardless of whether quiescence is selected based on star-formation activity, rest-frame colours, or structural characteristics. This flattening occurs at sizes of ∼1 kpc at z ≤ 1. As a result, a double power law is preferred for the stellar mass–size relation of quiescent galaxies, at least above 10$^7\, {\rm M}_\odot$. We find no strong redshift dependence in the slope of the relation of star-forming galaxies as well as of high mass quiescent galaxies. We also show that star-forming galaxies with stellar masses $\ge 10^{9.5}\, {\rm M}_\odot$ and quiescent galaxies with stellar masses $\ge 10^{10.3}\, {\rm M}_\odot$ have undergone significant size growth since z ∼ 2, as expected; however, low mass galaxies have not. Finally, we supplement our data with predominantly quiescent dwarf galaxies from the core of the Fornax cluster, showing that the stellar mass–size relation is continuous below 10$^7\, {\rm M}_\odot$, but a more complicated functional form is necessary to describe the relation.

Item Type:
Journal Article
Journal or Publication Title:
Monthly Notices of the Royal Astronomical Society
This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version Kalina V Nedkova, Boris Häußler, Danilo Marchesini, Paola Dimauro, Gabriel Brammer, Paul Eigenthaler, Adina D Feinstein, Henry C Ferguson, Marc Huertas-Company, Evelyn J Johnston, Erin Kado-Fong, Jeyhan S Kartaltepe, Ivo Labbé, Daniel Lange-Vagle, Nicholas S Martis, Elizabeth J McGrath, Adam Muzzin, Pascal Oesch, Yasna Ordenes-Briceño, Thomas Puzia, Heath V Shipley, Brooke D Simmons, Rosalind E Skelton, Mauro Stefanon, Arjen van der Wel, Katherine E Whitaker, Extending the evolution of the stellar mass–size relation at z ≤ 2 to low stellar mass galaxies from HFF and CANDELS, Monthly Notices of the Royal Astronomical Society, Volume 506, Issue 1, September 2021, Pages 928–956, https://doi.org/10.1093/mnras/stab1744 is available online at: https://academic.oup.com/mnras/article/506/1/928/6307033
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1900/1912
Subjects:
Departments:
ID Code:
174787
Deposited By:
Deposited On:
23 Aug 2022 10:55
Refereed?:
Yes
Published?:
Published