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An Evolving and Mass-dependent σsSFR–M ⋆ Relation for Galaxies

Katsianis, Antonios; Zheng, Xianzhong; Gonzalez, Valentino; Blanc, Guillermo; P. Lagos, Claudia del; Davies, Luke J.M.; Camps, Peter; Trčka, Ana; Baes, Maarten; Schaye, Joop; Trayford, James W.; Theuns, Tom; Stalevski, Marko

An Evolving and Mass-dependent σsSFR–M ⋆ Relation for Galaxies Thumbnail


Antonios Katsianis

Xianzhong Zheng

Valentino Gonzalez

Guillermo Blanc

Claudia del P. Lagos

Luke J.M. Davies

Peter Camps

Ana Trčka

Maarten Baes

Joop Schaye

James W. Trayford

Marko Stalevski


The scatter (σsSFR) of the specific star formation rates of galaxies is a measure of the diversity in their star formation histories (SFHs) at a given mass. In this paper, we employ the Evolution and Assembly of GaLaxies and their Environments (EAGLE) simulations to study the dependence of the σsSFR of galaxies on stellar mass (Må) through the σsSFR–Må relation in z∼0–4. We find that the relation evolves with time, with the dispersion depending on both stellar mass and redshift. The models point to an evolving U-shaped form for the σsSFR–Må relation, with the scatter being minimal at a characteristic mass Må of 109.5 Me and increasing both at lower and higher masses. This implies that the diversity of SFHs increases toward both the low- and high-mass ends. We find that feedback from active galactic nuclei is important for increasing the σsSFR for high-mass objects. On the other hand, we suggest that feedback from supernovae increases the σsSFR of galaxies at the low-mass end. We also find that excluding galaxies that have experienced recent mergers does not significantly affect the σsSFR–Må relation. Furthermore, we employ the EAGLE simulations in combination with the radiative transfer code SKIRT to evaluate the effect of SFR/stellar mass diagnostics in the σsSFR–Må relation, and find that the SFR/Må methodologies (e.g., SED fitting, UV+IR, UV+IRX–β) widely used in the literature to obtain intrinsic properties of galaxies have a large effect on the derived shape and normalization of the σsSFR–Må relation.


Katsianis, A., Zheng, X., Gonzalez, V., Blanc, G., P. Lagos, C. D., Davies, L. J., …Stalevski, M. (2019). An Evolving and Mass-dependent σsSFR–M ⋆ Relation for Galaxies. Astrophysical Journal, 879(1), Article 11.

Journal Article Type Article
Acceptance Date May 5, 2019
Online Publication Date Jun 26, 2019
Publication Date Jul 1, 2019
Deposit Date Jul 16, 2019
Publicly Available Date Jul 16, 2019
Journal Astrophysical Journal
Print ISSN 0004-637X
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 879
Issue 1
Article Number 11


Published Journal Article (2.6 Mb)

Copyright Statement
© 2019. The American Astronomical Society. All rights reserved.

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