The high-redshift SFR–M* relation is sensitive to the employed star formation rate and stellar mass indicators: towards addressing the tension between observations and simulations

Katsianis, A; Gonzalez, V; Barrientos, D; Yang, X; Lagos, CDP; Schaye, J; Camps, P; Trčka, A; Baes, M; Stalevski, M; Blanc, GA; Theuns, T

Abstract

There is a severe tension between the observed star formation rate (SFR)–stellar mass (M⋆) relations reported by different authors at z = 1–4. In addition, the observations have not been successfully reproduced by state-of-the-art cosmological simulations that tend to predict a factor of 2–4 smaller SFRs at a fixed M⋆. We examine the evolution of the SFR–M⋆ relation of z = 1–4 galaxies using the SKIRT simulated spectral energy distributions of galaxies sampled from the Evolution and Assembly of GaLaxies and their Environments simulations. We derive SFRs and stellar masses by mimicking different observational techniques. We find that the tension between observed and simulated SFR–M⋆ relations is largely alleviated if similar methods are used to infer the galaxy properties. We find that relations relying on infrared wavelengths (e.g. 24 μm⁠, MIPS – 24, 70, and 160 μm or SPIRE – 250, 350, and 500 μm⁠) have SFRs that exceed the intrinsic relation by 0.5 dex. Relations that rely on the spectral energy distribution fitting technique underpredict the SFRs at a fixed stellar mass by −0.5 dex at z ∼ 4 but overpredict the measurements by 0.3 dex at z ∼ 1. Relations relying on dust-corrected rest-frame ultraviolet luminosities, are flatter since they overpredict/underpredict SFRs for low/high star-forming objects and yield deviations from the intrinsic relation from 0.10 to −0.13 dex at z ∼ 4. We suggest that the severe tension between different observational studies can be broadly explained by the fact that different groups employ different techniques to infer their SFRs.

Citation

Katsianis, A., Gonzalez, V., Barrientos, D., Yang, X., Lagos, C., Schaye, J., Camps, P., Trčka, A., Baes, M., Stalevski, M., Blanc, G., & Theuns, T. (2020). The high-redshift SFR–M* relation is sensitive to the employed star formation rate and stellar mass indicators: towards addressing the tension between observations and simulations. Monthly Notices of the Royal Astronomical Society, 492(4), 5592-5606. https://doi.org/10.1093/mnras/staa157

• Journal Article Type: Article
• Acceptance Date: Dec 24, 2019
• Online Publication Date: Jan 20, 2020
• Publication Date: Mar 31, 2020
• Deposit Date: Mar 25, 2020
• Publicly Available Date: Mar 25, 2020
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 492
• Issue: 4
• Pages: 5592-5606
• DOI: https://doi.org/10.1093/mnras/staa157
• Public URL: https://durham-repository.worktribe.com/output/1267411